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1. LK Transmission Grid A Faultable Transformers Transmission Grid A Power Supply CR 1 Transformer 2 CR2 Load PhaseA N rn N Fe 5 E a u rm ES 2 T IS em 1 2 4 Phase 8 A na H Mo HR A A 3 3 Phase C KA Lach MA U 03 i y eued u01 93UU09 J3 u oo a 8 82829885288 Transmission _ GridA Control Relays Panel 1 CRI A CRIB CR1 AF gt Y e NY T CR2 A CR2 B At O goo 009909 9 aued UONDSUUODISJU EE 990 gt gt T CR1 C CR2 C CY 121 1zovoc CR1 la VU CR2 Figure 22 Transformer Protection Simulation Line Diagram 37 Nicholas Kilburn The interconnection diagram shown in the bottom half of Figure 22 illustrates the connection of the SEL 787 relay to the control relays through the interconnection panel which in term interfaces to the transmission grid three phase contactors The layout of the control relays is directly indicative of that required to properly establish the latching functionality The physical connection of the single line diagram can be seen in Figure 23 below where the output of the relay contactors connection across interconnectors A and B will momentarily energise the relay coi
2. 36 Nicholas Kilburn 7 2 Design Once the operational functionality of the Lab Volt modules was established and the requirements of each component were established the development of the final simulation system became a simple process There is an experiment manual supplied with the protective relaying training system which describes a collection of example experiments These provide a structured process for development implementation and operable testing of the included experiments which helped in the development of the final transformer protection simulation Figure 22 illustrates the final developed simulation layout as adapted from the transformer differential protection example experiment from the experiment s student manual 15 The major modifications include the introduction of a secondary side three phase contactor and the removal of the associated Lab Volt supplied SSR protective relays The SSR Relays are replaced by the SEL 787 and interfaced to the three phase contactors through the latching control relays The interface of the control relays and CTs with the SEL 787 is achieved through the use of the interconnection panel modules and the associated patch cables This minimised clustering cables running between the Lab Volt system and the 787 relay connections The process and methods for this simulation development and operation can be viewed in the user manual available in Appendix 12 2
3. Global Positioning System Human Machine Interface Inputs and Outputs International Electrotechincal Commission Institute of Electrical and Electronics Engineers B type Inter Range Instrument Group time code Metal Oxide Semiconductor Field Effect Transistor National Instruments Phasor Management Unit Residual Current Device Labels associating relay functions to the SELogic equations 8 position 8 contact Registered Jack Supervisory Control and Data Acquisition Schweitzer Engineering Laboratories Source Impedance Ratio Solid State Relay The status indicator of a relay word Time Overcurrent Universal Serial Bus Variable Transformer Voltage Transformer Reactance to Resistance ratio 57 Nicholas Kilburn 12 Appendices 12 1 AcSELerator Quickset Manual Available via the external document titled AcSELerator Quickset User Manual available from the school of Engineering and Information Technology 12 2 Transformer Protection Simulation Manual Available via the external document titled Transformer Protection Simulation User Manual available from the School of Engineering and Information Technology 12 3 Simulation Event Data 12 3 1 Phase Overcurrent Transformer internal short circuit fault EVENT command output gt gt event SEL 787 Date 26 11 2013 Time 10 04 59 148 TRNSFRMR RELAY serial Number 2009300461 FID SEL 787 R202 V0 Z001001 D20100215 CID 53A1 o Iu nt currents A Pri
4. available Figure 9 shows the Expandable I O of the SEL 311L relay to provide a comparison between the two different slot I O systems Like the 751A and 787 the I O terminals can be removed and the relay enclosure opened to allow removal and replacement of individual slot I O cards However with this system there is no room to install extra or optional functionality without sacrificing the default capabilities SERIAL PORT in naling Le ty PORT 5 tu 09 AVL ARJAN ALAT AIS atelat Aid laig WAON ADI 20 ADS Aad ars vgl pa wm d OUT205 0UT206 Praia A N Y act A dei rg We CHANNEL X Figure 9 311L Relay I O 19 Nicholas Kilburn 5 AcSELerator Quickset Chapter 5 address the AcSELerator Quickset PC application including its features capabilities and importance in programing the SEL relays Siting Started wath File Edit View Communications Tools Windows Help Language crnonias esjaon po QUICKSET New Create new settings Read Read settings from a connected device Open Open previously saved settings Device Manager Open Device Manager Communication Configure communication parameters for a connection Manage Manage offline settings and databases Update Install and update Quickset software and drivers TXD GG OE Open Connected COMI Communications Port 9600 8 None 1 Terminal EIA 232 Serial File transfer YModem Y Settings RDB Figure 10 AcSELerat
5. the relay switching would be driven by the signals being supplied from the CT or VT The induction disc relay type is one of the most popular and widely used electromechanical relays because of its short operating time reliability and ability to be applied in almost any form of protective function voltage current frequency power etc 2 5e Nicholas Kilburn Electromechanical relays are generally limited in functionality and operational scope and are designed specifically for the protection function desired This means that to monitor more than one function on one component of the network multiple relay units are required to achieve the desired suite of protective functionality Figure 3 offers an example where each phase and neutral requires its own individual electromechanical relay for protection This often means that the protection relays are housed in large standalone cabinets dedicated specifically for each relay or set of relays for the application 2 2 2 Solid State Solid State protection relays are an alternative analog based system that has recently seen some increased implementation 2 These relays are just as capable as the electromechanical equivalents with a fraction of the footprint and an ability to be more than single phase single contact relays SSR s utilize the electric principles of MOSFETs to operate and thus have no moving parts yielding some fairly significant advantages including faster operation ti
6. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 A 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 2 Event wdgi Ph 50 Trip 10 Targets 11010000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 Freq Hz 50 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 winding One Current mag 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 Taw IBW1 ZC IGw1 11 a 1 0 1 0 1 4 0 00 0 0 0 0 00 00 00 00 0 0 0 0 2 SE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 winding Two Current Mag 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 TAW2 IBW2 Icw2 IGW2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 a 1 4 1 4 1 4 0 05 58 Nicholas Kilburn Line to line fault SUMMARY command output E gt sum SEL 787 Date 26 11 2013 Time 09 24 33 486 TRNSFRMR RELAY serial No 2009300461 FID SEL 787 R202 VO Z001001 D20100215 CID 53A1 EVENT LOGS 18 Event wdgl Ph 50 Trip Targets 11010000 Freq Hz 50 0 winding One Current Mag IAW1 IBWL bad IGW1 A 1 7 2 9 1 7 0 00 Winding Two Current Mag IAW2 IBW2 Icw2 IGW2 CA 1 4 3 7 3 7 0 02 gt 12 3 2 Negative Sequence Overcurrent Line to Line fault event SUMMARY command output F gt gt sum SEL 787 Date 26 11 2013 Time 09 29 34 406 TRNSFRMR RELAY Serial No 2009300461 FID SEL 787 R202 V0 Z001001 D20100215 CID 53A1 EVENT LOGS 20 Event wdgl 50Q Trip Targets 11010000 Freq Hz 50 0 winding One Current Mag Iawl IBWL ICW1 Toi a 1 6 2 9 1 7 0 00 winding Two Current Mag IAW2 IBW2
7. 51VA at 15A AC voltage Inputs Continuous Thermal Control Outputs Make Thermal Protection Pickup Dropout Time Update Rate Control Inputs Direct Coupled Range Accuracy Max Voltage Sample Rate Burden 300V L N 600 Vac for 10 seconds 30A 50A for 1 second 250Vac 330Vdc 6ms 1 8 cycle DC use 15 265Vdc independently adjustable 5 plus 3Vdc 300Vdc 1 16 cycle 0 24W at 125Vdc 60 Nicholas Kilburn 12 4 2 SEL 751A SEL 751A Feeder Protection Relay P N 751A02B1B0X6X811630 S N 2009320380 FID SEL 751A R402 V0 Z006003 D20100129 Power Supply Rated 24 48V DC Range 19 2 60Vdc Burden lt 25W AC CT Inputs Nominal 1A Continuous 15A Thermal 500A for 1 second Burden lt 0 01VA AC Voltage Inputs Rated 100 250Vac Continuous 300Vac Thermal 600 Vac for 10 seconds Burden lt 0 1VA Output Contacts DC Rated 250Vdc Range 19 2 275Vdc Make 30A Thermal 50A for 1 second Protection 360Vdc Output Contacts AC Max 240Vac Protection 270Vac Rated Current 3A at 120Vac 1 5A at 240Vac Thermal 5A Control Inputs Version DC ON DC OFF AC ON AC OFF Current Analog Output Current Voltage Load 1mA Load 20mA Load 10V Refresh Rate Error Analog Input Max Range Impedance Error Optoisolated 24V 15 30Vdc lt 5Vdc 14 30Vac lt 5Vac 10mA 20mA 10V 0 15kO 0 7500 gt 20000 100ms lt 0 55 20mA 10V 2000 current gt 10k
8. Configuration changes Sequential Events Recorder Recording of operations of relay through internal word bit assertion desertion monitoring Various Communication Protocol Support Ability to communicate to a variety of varying devices Modbus DNP3 TCP IP etc Mirrored Bits SEL Proprietary relay to relay communications protocol Synchrophasor PMU Time synchronized measurements monitoring Remote and Local control switches Local and remote control of relay elements Event Reports Reports detailing fault event specifics Metering Real time display of metered values with CT VT compensation HMI PC based control and monitoring of relay functionality Front Panel Interface Local Relay control and Status Monitoring Nicholas Kilburn 4 SEL Units Overview During the initial stages of the project it was found that amongst the relays there were units that shared several functional capabilities were easily replicated through appropriate programing or required additional hardware to be effectively utilized As a result the thesis focused on the following relays 421 751A and 787 All the relays have different power supply requirements nominal CT ratings and I O switching characteristics which are detailed in Appendix 12 4 product number and FID to allow establishment of settings without reading directly from the relay this process is detailed in Appendix 12 1 All the mon
9. PLTO2 COMM SCHEME ENABLED 2 PLTO2R PB2_PUL AND PLTO2 3 PLTO4S PB4_PUL AND NOT PLTO4 RELAY TEST MODE 4 PLTO4R PB4_PUL AND PLTO4 5 PLTOSS PB5_PUL AND NOT PLTOS MANUAL CLOSE ENABLED 6 PLTOSR PB5_PUL AND PLTOS 7 PLTOGS PB6_PUL AND NOT PLTO6 RECLOSE ENABLED 8 PLTOBR PB6_PUL AND PLTO6 3 10 11 45 Figure 18 Free Form Setting Example 6 2 7 3 Variables All the relays without automation free form based logic have the ability to configure a selection of variables and other functional logic bits and equations for various purposes including metering data communications alarming and functional interlocking These variables include latching bits counters timers and variables and math variables e Latching bits as the name suggests is a collection of bit set and reset logic which can be configured to latch the associated bit when the configured SELogic equation is true An example is the indication of momentary alarm conditions having existed and requiring interaction to reset without impacting the status original alarm relay word e The timers and variables can be programed to be time based from a given input trigger where pickup time and dropout time can be configured e The counters can be used to develop user defined count events where the user can program the count up and count down triggers reset trigger initial value and value output location An example where counters are utilised is the breaker wear
10. Thermal IG 0 18A Math Variables UBI 0 00 Analog Inputs Light Intensity FREQ 50 00 Hz Breaker Wear Load Profile Targets Contact I O Status IN101 IN102 SER Control Window OUT101 OUT102 OUT103 User Defined Targets Double Click on Target Label NA NA NA NA NA NA O Oo Oo E mm Oo NA El NA NA NA NA NA NA NA Co Ol O EI Co Ol O AUX 1 ENABLED LOCK O DISABLED BLOCK CLOSE CLOSE O nec seo O BREAKER CLOSED J UNDER FREQUENCY re TRIP BREAKER FAILURE SCH OPEN SEL 751A 003 HMI Driver Driver Version 5 13 1 6 Driver Date Configuration Default 1 TXO pop El Open Connected COM Communications Port 9600 8 None 1 Terminal ElA 232 Serial File transfer YModem 7 Settings RDB Disable Update Figure 16 HMI 751A Device Overview AcSELerator Quickset also offers a HMI window allowing display of all necessary relay elements and variables as well as allowing control of the relays I O and functionality The example illustrated in Figure 16 contains the device overview window for the SEL 751A relay The HMI can be accessed as long as the relay remains connected and can be accessed via a locally connected PC or remote connection However operation of the HMI will consume the communication resource which will cause any automated communications to be impossible Figure 17 contains a command window snapshot illustrating the continual serial communications during HMI operations The screen sho
11. and the variety of testing that could be conducted 40 Nicholas Kilburn 7 3 1 Nominal CT Current The first consideration was that the nominal CT input of the SEL 787 relay is only 1A From the specifications this meant that the steady state current signals being measured could not exceed 19 24 and would be unmeasurable below 0 02A assuming a X R ratio equal to 40 while the continuous current could be no larger than 15A to prevent thermal impacts upon the relay and the maximum current rating under momentary fault conditions is 100A It is common practise to select the CT ratios that will result in a secondary current that is as close as possible to the nominal rating of the relay 12 which provides a suitable overhead in the event of severe fault With the low simulation current and the selection of CTs available through Lab Volt none of these limitations would be exceeded However this did contribute to the simulation being run at 50 of the total possible Voltage to keep nominal currents as close as possible to 1A secondary The limitations imposed by the nominal CT input will need to be further considered during development of the standalone system particularly if the power delivery of the standalone system is significantly higher than that of the current Lab Volt system 7 3 2 Mismatched CT Ratios The Lab Volt protective relaying training system provides two Current Transformer modules one which contains 6 0 5 5 ratio C
12. line to line faults at the transformer terminals load and power supply single phase load removal and power supply control variations to induce a differential fault And for each different configuration settings for pickup levels detection modes phase residual and negative sequence time overcurrent protection and programmed time delays were all configured both individually and as a combination to observe any functional differences or benefits in the responses of the relay For all the simulations operations under nominal conditions were first carried out This involved enabling the relay without any entangled protection functions and using the HMI and command window to read the nominal current metered variables The configuration of the CTs being 1 1 in the relay meant that the displayed metering data was identical to the currents being measured slightly simplifying the configuration process For the purposes of testing a couple of ground fault tests were conducted to confirm that it would be impossible for the relay to properly respond due to the existence of the earth leakage circuit breaker on the three phase power supply This fault was initiated first on the transformer to ground and then using the Universal fault module while the relay was configured to respond as quickly as by through minimising any response delay elements In both cases the three phase power was disconnected before the relay had a chance to respond and the breaker
13. there is a collection of various SEL protective relay devices that remained an unknown entity until semester 1 2012 when the ENG454 students began investigating the devices At that point in time knowledge of how these devices worked and what functionality they could provide was unknown thus the ENG454 students began investigations into the devices As a part of this exercise the students collected and organized the various instruction manuals implemented an enclosure to securely mount the devices installed the required software on associated Computer and began developing a NI LabView cDAQ simulation system This system was to simulate a simple distribution network and a variety of different fault conditions to demonstrate operation of the devices The network illustrated in Figure 1 depicts the intended simulated system including the SEL units as originally designed by Brenton Sherston and Simon Digby 1 in the final stage of the ENG454 unit Bus 1 Bus 2 Bus 3 SEL 421 Synchronous Machine Transformer Transmission line SEL 311L General Load SEL 751A SEL 787 SEL 311L Figure 1 Designed Simulation Network 0 Nicholas Kilburn Following the completion of ENG454 in semester 1 2012 the final simulation remained incomplete and most of the required knowledge regarding the functionality of the SEL devices remained unknown or improperly defined The current state of the SEL Protection and Monitoring System is illust
14. time of the fault 28 e Nicholas Kilburn One other calculation that needs to be made for distance protection is that of the Source Impedance Ratio SIR which will determine if CVT transient detection is required This is to prevent the instantaneous or underreaching protection zone being tripped through an external fault Equation 3 illustrates the calculation to determine the SIR if this calculation results in a value less than five then the CVT detection can be disabled Equation 3 Source Impedance Ratio 11 lZsourcel SIR gt Reach X Lise More details about these calculations and configuration options can be obtained from the SEL 421 Applications Handbook as supplied with the relay The Applications Handbook contains a variety of example configuration steps to develop a variety of different protection functions that the SEL 421 is capable of providing The examples provided can be used to assist the development of simulations using the SEL 421 relay or similar protection functionality provided by the other available relays within the SEL Protection and Monitoring system 6 2 3 Differential Protection The configuration of the differential protection elements of the SEL 787 relay can be both a pain free or painful process depending on the network components The relay has input fields for the transformer rated MVA primary and secondary winding configuration CT ratio and nominal voltages which are used to calcula
15. use of letters allows quick identification of available protection functions and provides a method for easy identification of the device and or its function in physical installations and any related single line diagrams electrical wiring diagrams or even cable schedules The IEC document IEC 60617 Graphical Symbols for Diagrams defines the graphical symbol for each particular function which improves relay identification in any technical drawings 8 3 1 Protection Functionality The SEL Protection and Monitoring System Provides a variety of protective functionality and in some cases requires specific functional interactions to properly operate and protect electric distribution elements Table 1 contains a list of all the ANSI IEEE defined protection functions 9 that the SEL Protection and Monitoring System currently provides while Table 2 details the lettering variations where the usage will indicate which specific measurement component the function will monitor for fault detection e g phase negative sequence neutral etc Table 1 Available ANSI IEEE Protection Functions ID Variants Name Description 21 Distance Relay Distance protection based on Line Impedances mho relay zoned protection 24 Volts Per Hertz Protection from over excitation of a transformer based upon Relay nominal voltages and frequency 25 Synchronism Check Internal checks for synchronism of relay components 27 S Under voltage Pro
16. where neutral CT protection voltage protection and thermal protection functions can be applied to the transformer protection simulation system Doing so would allow replication of the necessary protective functionality applied to distribution transformers thereby improving the overall performance of the simulation This may be solved by simply borrowing the expansion cards currently installed in the SEL 7514 52 Nicholas Kilburn to explore the possibility of the optional functionality This is possible because both relays are built on the same design platform and the available expansion cards appear to be common in configuration and I O capabilities between the two relays 12 17 The installation of new expansion cards will require proper configuration within the relay and on the I O card itself the transition is not quite the same as a plug and play functionality of the expansion system used in modern desktop PCs 9 Investigate the acquisition of a second SEL 311L to allow development of a Line Current Differential Communications assisted simulation of a long distance transmission line This relay has integrated communication settings within the line current protection functionality The addition of this 294 relay will also allow demonstration of the benefits of relay to relay communications provided by the SEL proprietary Mirrored Bits communication protocol 10 Develop a system that incorporates the SEL 3351 Embedded PC and the mon
17. 113 m TAWL IBW1 Icwi IGwi TAW2 IBW2 ICw2 IGw2 2 2 1 1 0 0 4 0 7 0 0 13 1 1 0 3 0 0 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 1 0 0 4 0 8 00 1 3 1 1 02 00 0 1 0 9 11 00 0 4 0 9 1 4 0 0 2 1 0 0 4 0 9 0 0 1 3 1 1 0 2 0 0 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 1 0 0 4 0 8 00 1 3 1 1 02 0 0 N 0 1 0 9 11 00 0 4 0 9 1 4 0 0 3 1 0 0 4 0 8 0 0 1 3 1 1 0 2 0 0 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 1 0 0 4 0 8 0 0 1 3 1 1 02 00 as 0 1 0 9 1 1 00 0 4 0 9 1 4 0 0 4 1 0 0 4 0 8 0 0 1 3 1 1 0 2 0 0 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 1 0 0 4 0 8 00 1 3 1 1 02 00 Ve 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 5 1 0 0 4 0 8 0 0 1 3 1 1 0 2 0 0 da 0 1 09 1 1 00 04 09 1 4 0 0 Be 1 0 0 4 0 8 00 1 3 1 1 02 0 0 ee Ge 0 1 0 9 11 0 0 0 4 0 9 1 4 00 gt 6 1 0 0 4 0 8 0 0 1 3 1 1 0 2 0 0 2 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 2 1 0 0 4 0 8 00 1 3 11 02 0 0 2 ge 0 1 0 9 1 1 0 0 0 4 0 9 1 4 0 0 2 7 1 0 0 4 0 8 0 0 1 3 1 1 0 2 0 0 2 0 1 0 9 1 1 0 0 04 09 1 4 0 0 2 1 0 0 4 0 8 00 1 2 1 1 02 0 0 2 Gs 0 2 0 8 0 7 0 0 0 2 0 9 11 0 0 2 8 0 5 0 3 0 4 0 0 0 7 0 6 0 1 0 0 2 0 2 0 3 0 2 0 0 0 1 0 4 0 4 0 0 2 0 1 0 1 0 0 0 0 0 1 0 1 0 0 0 0 2 be 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 Serial No 2009300461 FID SEL 787 R202 V0 Z001001 D20100215 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 CID 53A1 EVENT LOGS 37
18. 13 12 Schweitzer Engineering Laboratories Inc SEL 787 Instruction Manual Schweitzer Engineering Laboratories Inc Pullman 2010 13 Schweitzer Engineering Laboratories Inc SEL 351 5 6 7 Protection System Data Sheet Schweitzer Engineering Laboratories Inc Pullman 2012 14 Microsoft Windows XP SP3 and Office 2003 Support Ends April 8 2014 Microsoft 2013 Online Available http www microsoft com en us windows endofsupport aspx Accessed 8 August 2013 15 Lab Volt Ltd INtroduction to Protective Relaying Students Manual LAb Volt Ltd Qu bec 1998 16 I Edmund O Schweitzer Negative Sequence Overcurrent Element Application and Coordination in Distribution Protection Schweitzer Engineering Laboratories Inc Pullman 1997 17 Schweitzer Engineering Laboratories Inc SEL 751A Instruction Manual Schweitzer Engineering Laboratories Inc Pullman 2013 56 Nicholas Kilburn 11 Glossary ANSI BNC cDAQ CT CVT DAQ DMM D Sub ENG454 GE GPS HMI 1 0 IEC IEEE IRIG B MOSFET NI PMU RCD Relay Word RJ45 SCADA SEL SIR SSR Target TOC USB Variac VT X R American National Standards Institute Bayonet Neill Concelman Connector Compaq DAQ Current Transformer Capacitive Transformer Voltage Data Acquisition Digital Multi Meter D Subminture Connector Industrial Computer Systems Design General Electric Company
19. 2013 SEL Protection and Monitoring System A report submitted to the School of Engineering and Information Technology Murdoch University in partial fulfilment of the requirements for the degree of Bachelor of Engineering Nicholas Kilburn Supervisor A Prof Graeme Cole Associate Supervisor Dr Greg Crebbin Nicholas Kilburn Abstract The protection of power distribution and transmission systems is a critical application in ensuring safe reliable and efficient supply of electricity to the consumers The protection allows for the mitigation of damage due to various network faults preventing equipment damage and reducing downtime that can often result Within the University there is a collection of digital protective relays manufactured by Schweitzer Engineering Laboratories where the functionality requirements and operational knowledge of the available devices remains largely unknown Thus this thesis was tasked with drawing out this knowledge and providing a means of demonstrating the functions of the available devices In order to develop this understanding the project was divided into several components familiarisation investigation Simulator development and operations testing The familiarisation and investigation components of the project allowed for acquisition of the required level of knowledge about the devices to enable development of a suitable Simulation platform to demonstrate the func
20. 27 Fault Event Summary 7 5 1 2 Residual For the application of the residual overcurrent protection function only winding two was configurable the use of a delta configuration on the primary side prevents the detection of any residual currents available This residual current protection function is derived directly from the three phase current metering data due to the absence of a neutral CT metering input on the relay Analysing the IGW2 metering element at nominal current yielded a residual current of less than the minimum configurable setting 0 14 thus the residual pickup setting was set to this value Throughout simulations the phase overcurrent elements remained configured to replicate normal operational configurations Figure 27 illustrates that in phase overcurrent trip events the residual element IGW2 is still below the minimum pickup setting During simulation testing the residual element only responded to the removal of one phase of the load This is because under these circumstances there was no introduction of overcurrent conditions on both the primary and secondary windings Figure 28 contains the event summary for the residual fault trip event showing that the residual metering element IGW2 has exceeded the configured pickup setting while not causing phase overcurrent conditions to result due to the removal of a single phase of the load 45 Nicholas Kilburn gt gt sum SEL 787 Date 26 11 2013 Time 09 36 2
21. 5 556 TRNSFRMR RELAY Serial No 2009300461 FID SEL 787 R202 V Z001001 D20100215 CID 53A1 EVENT LOGS 26 Event Wdg2 Gnd 50 Trip Targets 11010000 Freq Hz 50 0 Winding One Current Mag TAW1 IBW1 Icw1 IGW1 A 0 7 1 0 0 8 0 00 Winding Two Current Mag TAW2 IBW2 ICW2 IGW2 A 8 6 1 4 1 4 0 82 Figure 28 Residual Trip Event Summary 7 5 1 3 Negative Sequence Overcurrent Protection The relay provides negative sequence overcurrent protection which is best suited in the detection of and protection from line to line faults Because negative sequence overcurrent elements do not respond to balanced loads they can be set to operate faster and more sensitively than phase overcurrent elements for phase to phase faults on distribution systems Like ground overcurrent elements negative sequence overcurrent elements can be set below load levels 16 To test and confirm this phase overcurrent elements remained configured as previously while the pickup settings for the negative sequence elements were set to the minimum possible 0 1A The usage of this is justified after analysis of the phasor overview HMI window confirmed negative sequence elements to be OA or below minimum pickup during nominal conditions During simulation testing the negative sequence overcurrent protection elements responded to the introduction of line to line and phase load removal faults while the phase overcurrent element responded to the transformer wind
22. 51A02B1B0X6X811630 06BF CONFIG 21220221 03EF iedName 0380 type 028F configVersion 0629 gt 4 Figure 11 Communications Window The command window is a terminal emulator allowing serial based text communications to occur between the relay and PC It provides mechanisms to modify specific settings poll for relay metering event data relay control and status monitoring The command window will also display live communications when other parts of the package are communicating with the relay settings download HMI etc Figure 11 illustrates the appearance of the communications window showing the initial processes of connecting to the SEL 751A relay by entering the appropriate access level and then gathering specific relay version details to allow the settings editor to display the available functionality configurations 21 Nicholas Kilburn gt gt help AFT ANALOG BREAKER Arc Flash Self Test Test an analog output channel Display breaker monitor data Close Breaker Display or clear communications channel data Control Remote Bits and digital outputs Copy 4 settings group into another settings group Show current state of device counters Display Ethernet Status Report Display an event report Work with relay files Display GOOSE Communication Information Change a settings Group Display an event history or clear event data Synchronize the device date and time with t
23. Icw2 IGw2 a 1 4 3 7 3 6 0 02 gt gt Single Phase Load dropout fault SUMMARY command output F gt gt sum SEL 787 Date 26 11 2013 Time 09 33 18 016 TRNSFRMR RELAY serial No 2009300461 FID SEL 787 R202 VO Z001001 D20100215 CID 53A1 EVENT LOGS 22 Event wdgl 50Q Trip Targets 11010000 Freq Hz 50 0 Winding One Current Mag TAWL IBW1 ICW1 IGW1 a 0 8 1 0 0 7 0 00 winding Two Current Mag IAW2 IBW2 Icw2 IGw2 A 0 6 1 4 1 4 0 84 gt gt 12 3 3 Residual Overcurrent Single Phase Load dropout fault SUMMARY command output P gt gt sum SEL 787 Date 26 11 2013 Time 09 36 25 556 TRNSFRMR RELAY serial No 2009300461 FID SEL 787 R202 V0 Z001001 D20100215 CID 53A1 EVENT LOGS 26 Event wdg2 Gnd 50 Trip Targets 11010000 Freq Hz 50 0 winding One Current Mag Iawl IB ICW1 IGW1 A 0 7 1 0 0 8 0 00 winding Two Current Mag IAW2 IBw2 Icw2 IGw2 A 0 6 1 4 1 4 0 82 gt gt 59 Nicholas Kilburn 12 4Important Relay Specifications 12 4 1 SEL 421 SEL 421 P N S N FID Power Supply DC Range AC Range Frequency Range Burden Burden AC CT inputs Nominal Continuous Range Thermal Thermal Burden Protection Automation System 042126152A2AXH35XXXX 2008269404 SEL 421 R128 V0 Z012011 D20090428 125 230V 85 300V 120 230V 85 240V 50 60Hz 30 120Hz 35W lt 120VA 5A 15A 0 25 100A 500A for 1 second 1250A for 1 cycle 0 27VA at 5A 2
24. O voltage lt 0 5 un calibrated 61 Nicholas Kilburn 12 4 3 SEL 787 SEL 787 Transformer Protection Relay P N 27870XA0X0X0X810830 S N 2009300461 FID SEL 787 R202 V0 Z001001 D20100215 Power Supply Rated 110 250V DC 110 240V AC 50 60Hz Range 85 275Vdc 85 264Vac Burden lt 20W dc lt 40VA ac AC CT Inputs Nominal 1A Continuous 15A Range 0 02 19 2A Thermal 100A for 1 second Burden lt 0 01VA Output Contacts DC Rated 250V Range 19 2 275V Make 30A Thermal 50A for 1 second Protection 360V Output Contacts AC Max Protection Rated Current Thermal Control Inputs Version DC ON DC OFF AC ON AC OFF Current 240V 270V 3A at 120Vac 1 5A at 240Vac 5A Optoisolated 125Vdc 100 156 2Vdc lt 75V 85 156 2Vac lt 53Vac 4mA 62 Nicholas Kilburn 12 4 4 Secondary Relays Line Current Protection and SEL 311L SEL 351 Directional Overcurrent Relay Automation System P N 031111HDD3254X2X4 P N 035160H35B4XX1 S N 2009309181 S N 2007110113 FID SEL 311L 1 R410 VO Z104006 FID SEL 351 6 R403 V0 Z008006 D20100312 D20091028 Power Power Supply Supply 48 125V DC 48 125V DC 50 60Hz 125V AC 50 60Hz 120V AC Burden lt 25W Burden 25W Range 38 200Vdc 85 140Vac Range 38 200Vdc 85 140Vac SEL 3351 System Computing Platform SEE ee Protection Relay P N 335135741H0004VV7F3 P N 0387E0Y3X52X4X S N 2007214132 S N 2009131256 SEL 378E R605 V0 Z003003 SS Ae ES D20071025 Powe
25. OP1F2 IOP2F2 IOP3F2 Load Profile 2nd Harmonic 0 00 0 00 0 00 Targets Status IOP1F4 IOP2F4 IOP3F4 SER 4th Harmonic 0 00 0 00 0 00 Control Window IOP1F5 IOP2F5 IOP3F5 5th Harmonic 0 22 0 22 0 37 Figure 30 Initial Differential Metering HMI To account for this the TAPn values were doubled keeping the result within permissible bounds and this resulted in both operate and restraint metered values being within protective configurable bounds reducing these values below 0 68 As such the 087P element was thus configured to 0 7 and the differential protection elements were enabled Table 4 TAPn Calculations shows the TAPn calculations and adjusted calculations that were made to reach the successful configuration of the Differential protection elements The left most section contains the calculations with the real settings for the CT ratios while the middle contains the increased CT ratio calculation and the final section shows the resultant doubling of the configuration to allow operable configuration Table 4 TAPn Calculations Original Calculation CT Correction Calculation Final Adjustments Variable Primary D Secondary Y Primary D Secondary Y Primary D Secondary Y TAPn 23 80952381 15 19342814 2 380952381 1 519342814 4 761904762 3 038685627 MVA 0 005 0 005 0 005 0 005 VWDG 0 21 0 19 0 21 0 19 CTRn 1 1 10 10 C 1 732050808 1 1 732050808 1 Throughout the initial tests the phase overcurrent eleme
26. PG Accessed 5 November 2013 General Electric Company In Defense of Electro Mechanical Relays 2012 Online Available http www gedigitalenergy com multilin resource index htm Accessed 5 November 2013 Schweitzer Engineering Laboratories Inc Our Roots 2013 Online Available https www selinc com aboutSEL our_roots Accessed 5 November 2013 Schweitzer Engineering Laboratories Inc Who we Serve 2013 Online Available https www selinc com aboutSEL who_we_serve Accessed 6 November 2013 ANSI Device Numbers Wikimedia Foundation Inc 28 October 2013 Online Available http en wikipedia org wiki ANSI_Device_Numbers Accessed 5 Novermber 2013 E Csanyi ANSI IEC Relay Symbols Csanyigroup 14 April 2010 Online Available http www csanyigroup com ansi iec relay symbols Accessed 7 November 2013 E Csanyi ANSI Standards for Protection Devices Csanyigroup 13 September 2009 Online Available http www csanyigroup com ansi standards for protection devices Accessed 6 November 2013 10 J Horak Directional Overcurrent Relaying 67 Concepts 31 July 2010 Online Available http www basler com downloads DirectionalOC pdf Accessed 11 November 2013 11 Schweitzer Engineering Laboratories Inc SEL 421 Relay Instruction Manual Schweitzer 55 Nicholas Kilburn Engineering Laboratories Inc Pullman 20
27. TECTION FUNCTIONALITY eege eege ci 53 E IAN O 54 10 REFERENCES sosciseicevssnccseissuescevesuestenseseccensvencseecesneceeusovesseunswsseeusonssasceswsoesussnseseneswecsews 55 11 e D O oe A TA euren E E nenn nie ee e nenne ren e E A 57 12 APPENDICES ioscisessesssscsseissuescevesneseeusesecueuvoncsee sn ouscweuesvesse ue ows sieusowssesueowoswsussnssssesesseuows 58 12 1 ACSELERATOR QUICKSET MANUAL iyscsssecescssscsxeutscdunenes odvventzeverssonsdonoadcoSonesdeetonsadastenensvenenessastecssszsdoveess 58 12 2 TRANSFORMER PROTECTION SIMULATION MANUALE 58 12 3 SIMULATION EVENT DATA AAA Senstcechededeesduusedeenedeeds 58 12 3 1 Phase Overcurrent ss nasneninsri nema aana a AA E EE EAE EE NA E RREAN 58 12 3 2 Negative Sequence Ouercurrent 59 123 3 Residual Overcurrent visic seccivscivisassseccinescvessaceansdesecssssasectedeuessuscsavachedensesusccuvachodagecsesssuvaieadaeness 59 12 4 IMPORTANT RELAY SPECIFICATIONS sssssscccccccssssssnccccescesssssnnseeeeecesssssaeeeeesessssesanseeeeseessssnaeseeeeseeees 60 PAD SPLA E 60 KE EE E 61 DOA EE 62 12 4 4 Secondary Relays cscccscscseesseessessecsseessecescesseesseceseesseesseesseeeseeeeeeseeeeeseeeseeseeeseeeseeeeeeeseeeseeeenes 63 Nicholas Kilburn List of Figures Figure 1 Designed Simulation Network ven 1 Figure 2 SEL Protection and Monitoring Rack ue 2 Figure 3 Overcurrent Protection Relay lol 5 Figure 4 Three Phase Overcurrent Relay cccescsssssssesces
28. Ts designated Module A while the second contains 3 1 5 ratio CTs and 3 2 5 5 CTs designated Module B Initial operative testing with the Module a CTs yielded some unexpected results one of the CTs was failing to scale the input current according to the rated ratio unlike the remaining 5 CTs Upon further investigation it was found that that particular CT was internally shorted causing the undesirable measurement results As result of this the CT module B was to be used for all remaining tests while a replacement CT for Module A was acquired The use of Module B would cause a mismatch in CT ratios for the application of differential protection The mismatch would be partially reduced by the use of a Delta Wye three phase transformer configuration however slight this improvement may become The configuration procedure for the differential protection elements would help to account for this difference and allow differential protection to be appropriately simulated The mismatch in CT ratios between primary and secondary would not have a significant impact upon overcurrent protection elements as each is configurable separately One issue associated with the step up CT ratios results from a programing limitation in the SEL 787 relay configuration where the lowest CT ratio configurable is 1 1 meaning that the relay is incapable of scaling the measured currents to the precise Lab Volt system currents There is an advantage with this configuration which is t
29. a 1kW rated resistor were acquired from within the university for initial testing purposes However shortly after this the testing process was simplified through the acquisition of a collection of various pieces of Lab Volt equipment 7 1 Lab Volt The process of simulation development was streamlined with the discovery of the Lab Volt Protective Relaying Training system available within the university The units available include the Universal Fault Module Faultable Transformers Transmission Grid A Control Relays and a collection of CT and VT modules along with two interconnection modules their associated patch cables and essential power supply units The use of this Lab Volt equipment had not been explored in any of the previous units resulting in a small period of operational investigation to ascertain correct limits procedures and capabilities each module required provided This process proved fairly straight forward through front panel interior and specification analysis leading to a period of operational guess and check testing to ensure that total operational functionality had been acquired The majority of the process was conducted with a multimeter to check for continuity voltage or resistance to confirm operational understandings 33 Nicholas Kilburn 7 1 1 Faultable Transformer Module The Faultable Transformer Module shown in Figure 19 contains three isolation transformers one per phase with a variety of inp
30. a majority of the power wiring and programing requirements and procedures to allow development of a successful protection simulation 6 2 Significant Findings 6 2 1 Compaq DAQ The first and most significant finding is that the minimum CT pickup setting within the available relays is 0 1A or higher a significant increase on the maximum possible current output by the cDAQ card of 20mA This discovery caused the cDAQ LAbView based simulation to becoming infeasible as a means to demonstrate the protective functionality of the relays given that the majority of protective functionality 27 Nicholas Kilburn provided is based upon the CT secondary current being measured This had a significant impact on the project due to the significant amount of time that had elapsed before this fact was confirmed through careful analysis of all the relays documentation and configuration settings This discovery lead to a significant change in the direction of the project resulting in the need to acquire and develop a hardware based simulation The resulting hardware investigations would uncover the existence of the Protective Relaying Lab Volt Training system and the associated available components within the University The details of this system are identified and explored in Section 7 Simulation Development Later investigations have identified a potential application for the cDAQ system this being alarming and remote control functionality where
31. actors Y ENABLED rr gt DIFFERENTIAL INST OVERCURRENT gt TIME OVERCURRENT UNDER VOLTAGE DER FREQUENCY VOLTS HERTZ Figure 26 Fault event SEL 787 Front Panel Figure 27 contains the fault event summary as displayed through the Communications window after the use of the sum command showing that only one phase metering element has exceeded pickup settings enough to generate a trip condition The use of the summary command produces specific fault 44 Nicholas Kilburn information which includes the target relay ID time and date the type of fault event responding relay targets I O and the metering data at the time of fault It should be noted that this report indicates the network frequency however without the ability to measure the network voltages at the time of the fault this is only an indication of the expected frequency There is an alternative command called EVENT which will provide various snapshots of metering data and control status leading up to and following the fault event Further examples can be observed in Appendix 12 3 SEL 787 Date 30 10 2013 Time 11 19 32 088 TRNSFRMR RELAY Serial No 2009300461 FID SEL 787 R202 V0 Z001001 D20100215 CID 53A1 EVENT LOGS 11 Event Wdg1 Ph 50 Trip Targets 11010000 Freq Hz 50 0 Winding One Current Mag TAW1 IBW1 ICW1 IGW1 A 1 4 1 0 1 0 0 00 Winding Two Current Mag TAW2 IBW2 ICW2 IGW2 A 1 4 1 4 1 4 0 04 Figure
32. al contacts and time delayed contacts which enable the introduction of various fault elements dependent upon the usage of the output connectors Figure 21 illustrates the universal fault module which consists of three sections The first is the powered switch and the associated activated contact coils and time delayed coils The second is the collection of control relay contactors and power relay contactors The third section contains a collection of resistive outputs to provide a variety of short circuit current conditions This module allows the introduction of various network level external faults which can be applied to any component of the simulation network UNIVERSAL FAULT MODULE 0 1 10 4 oo INTERNALLY CONTROL RELAY CONTACTS we POWER RELAY CONTACTS tawv man 250 V 254 Fo 09090 2 Goss 6 LINE TO LINE LINE ar FAULT rar 6 1777 er q Aa EV sa Rm Figure 21 Universal Fault Module 7 1 4 Control Relays The control relay modules are a collection of latching non latching and time delayed SPDT and DPDT relays with interconnectors to drive the coil and interface with the contact outputs All of the available control relays are of type C with NO and NC switching terminals Also included is a dedicated DC power supply to provide sufficient voltage to energise or de energise the relay coils through a switching external interface such as the output contacts of the protective relays or suitably rated switches
33. ay with only CT inputs could also be used to emulate negative sequence protection earth fault protection breaker failure protection and thermal overload through appropriate programing This means that one digital relay has the potential to replace any number of electromechanical relays saving space and cost Because of this the digital relays are designed or created to meet the needs of a certain application e g transformer protection feeder protection and not the protective function type required The transition from electromechanical to microcontroller technology has allowed for the inclusion of modern communications related technologies thereby improving the monitoring operability and control and network integration of protection relays Some of the extra features include e The introduction of communications and SCADA the primary source for most of the following features allowing remote and local interactions of other relays users and control systems e GPS integration allowing accurate timekeeping e Synchronized Measurements Synchrophasor synchronized measurements based on the GPS clock which improves fault event monitoring and reporting e Automation the ability to automate functions within the relay and other devices as part of the protection system for example to signal other protection relays to open respective breakers e HMI allows for remote and local monitoring of relay specific values statuses and event
34. capable of reading and driving the digital I O in the initial simulation system and can be used to interface the external control or alarming capabilities as addressed in section 6 2 1 Compaq DAQ Other relays such as the SEL 787 and SEL 751A where these switching pickup levels are indicated on the relay I O tag and related to the power supply the 787 has 110 V AC power supply with 125 V DC switching specs while the 751A has a 24V DC supply with 24V specs The on off levels of both of these specs can be seen in Appendix 12 4 which contains the important relay specifications This means that for both these systems the digital inputs can t be triggered by the low voltage output that the cDAQ currently provides 6 2 6 Communications Functionality There are communication functionalities that either cannot be demonstrated due to lacking necessary hardware The biggest impact of this is seen in the SEL 311L which uses communications to allow operation of the line current differential protection functionality This requires fibre optic hardware and an identical 311L relay to communicate with and allow the protective functionality to be demonstrated in 30 Nicholas Kilburn the context of long distance transmission line protection There are target elements within the relay that become true in the absence of a paired 311L relay impacting the behaviour of the relay often resulting in false trip events due to the lacking incoming differe
35. ce and direction protection functions to be configured to produce a suitable simulation platform By using the Lab Volt Protective Relaying Training system a simulation can be constructed to an extent that the understanding of the operational capability of SEL functionalities can be determined and demonstrated like the Transformer Protection Simulation One suggestion though is to develop the simulation function by function separately the conflicts that can arise when combining operational functionality can result in undesirable operations or unexpected results 9 2 General Hardware 2 Investigate the possible removal of the three phase power supply earth leakage circuit breaker or using an alternative power source without this protection The existence of this circuit breaker prevented the operational analysis of the relay during any form of fault to ground This limited the ability to completely explore the SEL 787 s protective capabilities in a wide range of faults and the configurations required to adequately and simultaneously protect against a variety of different fault conditions Once this is completed the transformer protection simulation system can be upgraded to include ground An improvement to the simulation can result from the acquisition of a more capable higher rated load bank resistive and reactive providing a greater operational capability Doing so will allow for higher fault levels to be developed during simulations allow
36. ce of this device was confirmed by initiating a ground fault on the Faultable Transformer module which caused the three phase power supply to trip off by tripping the earth leakage circuit breaker The low operating pickup 42 Nicholas Kilburn current of this circuit breaker prevents the 787 relay from detecting any kind of fault where reasonable pickup settings are configured 7 4 SEL 787 Configuration The configuration process for the SEL 787 relay included the following steps full details of this process can be found in Appendix 12 2 Transformer Protection Simulation Manual e Disabling all conflicting or unnecessary functionality including most monitoring including the Through Fault feature e Configuring the primary and secondary CT connections and CT ratios e Running a normal non relay protected simulation to obtain the nominal current and differential element data to develop appropriate pickup levels and configuring the elements and enabling the protection functionality e Associating the outputs and inputs to control and monitor the individual control relay three phase contactor status e Modifying the trip and close logic to respond to the protection targets e g 51P1 phase overcurrent 51Q1 negative sequence overcurrent 7 5 Simulation Results For the purposes of testing the simulation a variety of faults were introduced including internal transformer winding short circuits external short circuits
37. chanical protection relay as installed in its electrical cabinet this particular relay is an overcurrent protection relay type 50 used in this instance to protect local generators The black blocks below and above the relays are test points that allow isolation of the relays from the equipment for testing This prevents the test from interrupting supply to the consumers 49 Nicholas Kilburn Figure 3 Overcurrent Protection Relay 3 The vast majority of available electromechanical relays available can be classified under the following types based upon the mechanism responsible for opening closing the relay contactors e Attracted Armature e Induction e Moving Coil e Motor Operated e Thermal All of these types have their advantages and disadvantages such as inherent operation delays or simple and accurate configuration and operation The type selection generally is based on needs of the application The type depicted in Figure 3 is an induction disc where current flowing through a set of electromagnetic coils induces a current on the rotatable disc When this induced current produces a force exceeding that applied by the opposing spring tension the disc will rotate causing the relay contactors to open One advantage of the induction disc mechanism is that a higher fault level results in a higher coil current thus causing faster disc rotation In this instance as with most of the other types of electromechanical relays
38. cteecsceseecesscenes 13 4 1 PRIMARY RELAYS paraire arara LEES EES EEN REN 13 4 1 1 SEL 421 Protection Automation Control 13 4 1 2 SEL 751A Feeder Protection Relay EE 14 4 1 3 SEL 787 Transformer Protection RelAY csccssccssssessssscssscsccessecesesssecseeeeseeeseceseseseseeeeneeeneeenes 15 4 2 SECONDARY REENEN deed a a 16 4 2 1 SEL 311L Line Current Differential Protection and Automotion 16 4 2 2 SEL 351 Directional Overcurrent Relay ooooconoccnononononononanonnnonnnononononononononononono nono nono nono nonnnos 16 4 2 3 SEL 387E Current Differential and Voltage Protection Relay ue 17 4 2 4 SEL 3351 System Computing Diottorm EE 17 4 3 MODULARITY E 18 Nicholas Kilburn 5 ACSELERATOR QUICKSET ssesesssseseesesssscsesseseososessoseosososeosessossoesseseososessosessssosessessos 20 5 1 COMMAND WINDOW isvecniehsrcvvcessenuotencaesscessenuptonchsescossanhedenchddstoesanhsdehcesvodeesheds Ae deeg Gedeelt eegen 21 5 2 el EO E rai 23 5 3 DETTINGS HDITOR AAA O 24 FA AM A TN 25 6 RELAY INVESTIGATION ccccccccccccccccscccccesccscccccescccecsccescccvesscscccccesccescsccecccesessees 27 6 1 FAMILTARIZA TON EE 27 6 2 SIGNIFICANT FINDINGS svesecssccccsescesvcentsececcesvesosntesetercasuedeueneretecsrssenevesteeleceuddetebecteedecondentabectesseyevaieteseses 27 6 2 1 EIERE EE EE 27 622 Distance Protec his tuad seis dscishis edd hes eel a een 28 6 2 3 Differential Protection EE 29 6 2 4 KE 30 6 2 5 Switching R
39. ction The 787 that is available in the project room only offers the basic default suite of protection as there are no expansion I O cards installed The unique feature of the SEL 787 is the Transformer Through Fault event monitor which analyses the network conditions during a fault ride through event and reports back on the thermal operation of the transformer during that fault allowing ride through damage mitigation procedures to occur The configuration for this is user definable by setting alarms and the transformers nominal impedance The monitor will activate for all non internal faults and monitor internal conditions using the measured line currents and calculates thermal characteristics using the configured line to line voltage transformer MVA rating CT ratios and the measured primary current to develop a thermal curve and check that the transformer is not operating beyond the defined limits The report would indicate if this is the case and thus pickup levels would then need to be reduced to prevent thermal overload of the transformer The control of the attached circuit breakers operates similar to the other relays the difference being the control interaction of a Lockout Relay 86 a requirement of the application of transformer protection A Lockout Relay is similar in operation to a latching relay where a manual reset is required to reclose the contactors This is to prevent reconnection of the transformer in the even the transformer
40. e SEL 421 which is known to have digital I O with configurable pickup and dropout levels This would allow the cDAQ to simulate circuit breaker control and monitoring as part of the original software based simulations The use of this could be applied to remote control and monitoring simulations The cDAQ combined with an appropriately developed LabView program could be utilised to simulate a remote HMI panel for manual controls and status monitoring This is possible because the available I O can be tied to replicate or control the status of various relay elements targets and control relay words This can replicate a physical hardwired I O panel and alarming equipment that may normally be attached to provide easy control and monitoring of relays elements without diving into the deep front panel display menus 54 Nicholas Kilburn 10 References 1 2 3 4 5 6 7 8 9 B Sherston and S Digby SEL Power Protection Simulation System Murdoch University Perth 2012 E Csanyi Protection Relays Important Informations Csanyigroup 14 September 2009 Online Available http www csanyigroup com protection relays important informations Accessed 5 November 2013 Wtshymanski File Protective Relays Hydroelectric Station JPG Wikimedia Foundation Inc 8 September 2010 Online Available http en wikipedia org wiki File Protective_Relays_Hydroelectric_Station J
41. ectional Overcurrent Relay The SEL 351 Directional Overcurrent Relay which is the top most relay shown in Figure 7 is a two slot rack mountable protection relay designed to protect against forward and reverse direction overcurrent This is achievable through monitoring the phase relationships of the sequence components of the AC 16 Nicholas Kilburn system 10 The main protective functionality provided by the SEL 351 relay includes 25 27 32 50 50BF 51 59 67 79 and 81 Also available is a collection of monitoring functionality similar to that available from the other relays Again the majority of functionality available can be demonstrated using the three primary relays 4 2 3 SEL 387E Current Differential and Voltage Protection Relay The SEL 387E Current Differential and Voltage Protection Relay is a three slot rack mountable protection relay the third relay shown in Figure 7 which provides localized current differential protection and a variety of voltage based protection including over under voltage and frequency monitoring The relay contains three sets of three phase CT inputs to provide differential protection for 2 or 3 winding transformers or other local network elements There are 3 VT inputs and one neutral connector available to enable the voltage based protection functions The specific protection functions provided by the 387E relay include 24 27 50 51 59 67G and 87 along with a variety of metering and
42. eeseeeeceeceseeeeceacecceseeesecceacesessaeeaceaeeseseaseaeeaeeeseneease 6 Figure 5 Alternative Digital Protection Relay eeessessesceceesceseeecceeceseeseeeeeeceeseeseeceeaeeseeseseaeeaeeseeseseaeeas 9 Figure 6 Primary Relaysyi sccsscieses cesedssueseseescdvsdeoecevedeas eet NEES Eed Snbebeag deyniesssetebsopSnendenseveedensve 13 Higiire 7 A fagssavessetesadt neseaveeezevasastess 16 Figure 8 751A Relay Expandable Slot I O ENEE 18 Higure 9 311L Relay I O ici adn 19 Figure 10 AcSELerator Quickset Home ENEE 20 Figure 11 Communications Window EEN 21 Figure 12 Terminal Commands Overview SA 22 Figure 13 SELogic Equation Field sssssssssscsessescsossncssssoossnseasttscsossocenstssssnssacesstcssessaesssseossossastsssssses 23 Figure 14 SELogic Editor Window ENEE 23 Figure 15 Settings Editor 787 sseccsessscatocessccsves scevdoss scecsveassecuocesscasees io ad a aia piecuoes ENEE ne 24 Figure 16 HMI 751A Device Overview 25 Figure 17 HMI Communications Impact ENEE 26 Figure 18 Free Form Setting Example AANEREN 32 Figure 19 Faultable Transformer Module 34 Figure 20 Transmission Grid Module 35 Figure 21 Universal Fault Module AEN 36 Figure 22 Transformer Protection Simulation Line Diagram EEN 37 Figure 23 Physical Control Relay Connection ecessssesssecceceeeeeeeecceeeeseecceaceaeeseeaseceeaeeseeeceeaeeaeeseeeesenees 38 Figure 24 SEL 787 I O Connection Diagram ccsccssscssscssscs
43. elements analogs and variables to your expression Deviceword Bits Analog Quantities Figure 14 SELogic Editor Window Both Figure 13 and Figure 14 illustrate the SELogic equation for the Unlatch Trip relay word ULTRIP target of the SEL 751A relay where the SELogic equation will remain true as long as the targets for function 51 time overcurrent protection elements remain false and the status of the breaker remains closed 52A The moment either one of those relay word targets becomes true the Unlatch Trip target will become false while the related Trip target should become true indicative of the presence of a fault 232 Nicholas Kilburn 5 3 Settings Editor E AcSELerator Quicks per 787_Current File Edit View Communications Tools Windows Help Language 5 X G EOH H8 R OO e n o 4 0 Global D D General Configuration Event Messenger Settings Group Selection MVA Maximum Transformer Capacity MVA Synchronized Phasor Measurement OFF en Breaker Failure Through Fault Monitor ICOM Define Internal CT Conn Compensation Analog Inputs In w Select Y N Analog Dutputs Input Debounce A Data Reset Control WICT Winding 1CT Connection efec Loro DELTA y Select DELTA WYE 4 0 Group1 4 0 Set CTR1 Winding 1 Phase CT Ratio Identifier i Range 1 5000 Configuration Transtormer Differential Elements WICTC Winding 1 CT Conn Co
44. eption of the 751A and 787 relays Expandable and or modular layout allows easy replacement of devices easy addition removal of optional functionality and devices can be upgraded when new functional sets or inputs are required This is achieved by the slot I O card structure implemented by all the relays and is similar in concept and operation to the expansion cards graphics networking etc found in the modern desktop PC Figure 8 as an example shows the 751A relay with its I O interconnects with the rear panel removed showing the internal slot card structure and internal connections Figure 8 751A Relay Expandable Slot I O The components in this particular relay include Slot A Power supply and base digital I O Slot B CPU and external communications interconnectors serial Ethernet fibre optic Slot C Digital I O expansion 4 inputs and 4 outputs Slot D Empty Slot E Analog I O expansion 4 inputs and 4 outputs Slot Z CT inputs one for each phase and neutral measurement 18 0 Nicholas Kilburn The expansion I O cards allow for additional functionality such as voltage monitoring RTD monitoring expanded external alarming and control to become available to the relay As a point of comparison the 787 relay uses the same I O slot structure as the 751A relay however the available unit only has slots A B and Z occupied meaning that only the basic current protection functionality and circuit breaker control are
45. equirements sccssssscsscesceseeeseescesceeeseseescesceceeseeseesceeaeeseeseeaeeaeeaeeaeeeeeaeeaeeeeeeees 30 6 2 6 Communications bunctionoghtu ue 30 6 27 Configuration Capabilities lt A ih ae eee AN S 31 7 SUIMULATION PLATFORM DEVELOPMENT cccccsscssccesccccccccscccccesccccccccecccevessees 33 7 1 BE e EE 33 7 1 1 Faultable Transformer Module 34 7 1 2 Transmission EE 35 7 1 3 t EE TEE 36 7 1 4 COME RELAYS eege deeg EENS 36 7 2 RE 37 7 3 DESIGN CONSIDERATIONS aaiae a a a aaa E aa a a Eai 40 7 3 1 Nommal CT CUTE ici 41 7 3 2 Mism tched e E 41 7 3 3 RE Te E 42 7 3 4 Type 68 Lockout REGU ccisccastsccssesscsnccestbactaesscdesdessbastaessdascdesdsasdaasadascdessbadsaassnascdeddeasiaesanecaaesiiess 42 7 3 5 Earth Leakage Circuit Breaker EEN 42 SC ER E CONFIGURATION E 43 7 5 SIMULATION RESULTS peiris ioter oreren aE AE ETENEE E EIR EET EEEa 43 7 5 1 Overcurrent Protection EEN 44 7 5 2 Differential Protech A sates sahtacdeadl getsasan E SEENEN E AER 47 8 CONCLUSION scccccccsccccccccccrcccccccrsccsccecsecsccecsecsscessecsccessecsscecsccsscessecsscesecesscesseense 50 9 RECOMMENDATIONS 200ss0ss0sssossassnsnnnsnssnnnnnnsnnnnnnsnnsnennnnnssnnsnnnsnsnnnsnnssnsnnnnnnsnnensnsnsen 51 Nicholas Kilburn 9 1 LAB VOLT EQUIPMENT vassicsciscessonsotecseovecessonnodecsesdesossonteceasesvssvecantecessesVorenshebecenses ocnnchoeeisesesVounkpnenetecsves 51 9 2 GENERAL HARDWARE iio 51 NN EE 52 9 4 PRO
46. evice operations Nicholas Kilburn Figure 5 Alternative Digital Protection Relay 2 4 Schweitzer Engineering Laboratories Inc Schweitzer Engineering Laboratories SEL is a company founded by Edmund O Schweitzer in 1982 it is based in Pullman Washington and was the first company to develop and manufacture digital protection relays in 1984 5 To this date the company continues to develop embedded systems for control metering monitoring and protection of power systems and remains one of the leaders in digital protection relays as ranked by national USA and international utility companies 6 SEL remains at the forefront of innovation as highlighted by the recent introductions of load encroachment protection the standardization of Synchrophasor measurements in all digital relays and the development of a secure and highly reliable relay to relay communications protocol SEL Mirrored Bits As the title of this thesis may suggest SEL manufacture the digital protection relays that comprise the SEL Protection and Monitoring System Or Nicholas Kilburn 3 Relay Functionality The SEL Protection Relays provide a variety of protective functions with a specific means of identifying said functionality The protection function for all protection relays can identifiable by a number which indicates the function of the device and adheres to the ANSI Standard Device Numbers defined in the ANSI IEEE Standard C37 2 7 The
47. for the remaining relays that comprise the SEL Protection and Monitoring System The completion of these tasks would allow demonstration of the vast extent of protective functionality and its incorporation into a comprehensive distribution protection simulation 50 Nicholas Kilburn 9 Recommendations Following completion of this project there are several recommendations that can be made for future project work and overall system improvement 9 1 Lab Volt Equipment 1 Acquisition of a Faultable Transmission Line module not currently available within the university from Lab Volt to allow development of a series of simulations for transmission line feeder directional distance and power protection functions This module simulates the impedance which is a known value of a transmission line and provides a means to introduce faults midway along the simulated line The line and feeder protection functions can be simulated in a similar manner to the transformer protection system already developed The known impedance of the module combined with an addition of voltage monitoring will allow the simulation of power based protection And with the addition of the Source Impedance module already available within the university distance and direction protection can be effectively simulated Like the Faultable Transmission Line module the Source Impedance module has a known value which when configured correctly can permit the distan
48. gs are entered the nominal line voltage fields are disabled preventing these from being adjusted for future calculations 49 Nicholas Kilburn 8 Conclusion The development of a comprehensive understanding of the SEL protective relays available within Murdoch University was the primary focus of this project as this would enable development of a simulation to demonstrate the capabilities and functionality of associated devices Throughout of the project various details and knowledge about the various collective relays have been acquired which includes their scope of operational functionality their individual requirements and the means and methods to program them The use of this acquired knowledge was then used to successfully develop an operational simulation for transformer protection through the use of available Lab Volt equipment and the SEL 787 Transformer Protection Relay The incorporation of the Lab Volt equipment in the final simulation allowed for successful demonstration of the SEL 787 s current based protection functionality and provides the groundwork necessary to allow further development of Lab Volt based simulations for voltage frequency power and other current based protective functions that the remaining relays are capable of providing Despite the development of a successful simulation further hardware acquisition investigations and functional testing is required in order to develop appropriate simulations
49. he IRIG source Display or clear load profile data Test a communications channel Display MAC Addresses View DNP or Modbus Map Display metering data Open Breaker Send Ping messages to a network device Pulse a digital output Exit to Access Level 0 Restore settings to manufacturing default configuration Display Sequential Events Recorder records Modify or display device settings Display or clear relay status Display an event summary Display internal binary variable values CLOSE COMMUNICATIONS LOAD_PROFILE LOOPBACK MAC MAP METER OPEN PING PULSE QUIT RESTORE_RELAY SER SET SHOW STATUS SUMMARY TARGETS 4 Figure 12 Terminal Commands Overview 751A Figure 12 illustrates the command window after the input of the help command Not shown is the requisite procedure to reach level 2 access to enable usage of the visible commands among others available This shows the particular commands available to the SEL 751A relay that enables control monitoring or event report requests The operations available through the communications window can be utilised with another third party terminal or serial communications program However the usage of such programs would require extra background knowledge to establish communication and effectively communicate with the relay One of the more useful commands common to all relays is the Summary command which will display the required data of the most recent fa
50. he fault currents of the simulation are exaggerated permitting the relay to easily detect the smaller fault currents that the Lab Volt system generates in the current configuration 410 Nicholas Kilburn 7 3 3 Lab Volt Ratings The second consideration was the current ratings of the Lab Volt equipment particularly the resistive load modules used Where 0 35A was the maximum possible measured from the primary side of the transformer During initial system testing a multimeter was connected in series with one phase of the load to monitor and ensure safe operation conditions This resulted in the simulation being operated at 50 max voltage which would keep the load current below the limit imposed by the resistive load The current ratings of the other lab Volt modules were also monitored but at this operating limit there were no associated overcurrent issues In an attempt to overcome the limitations imposed by the resistive load a three phase four pole squirrel cage induction motor already installed in the Lab Volt rack was connected in place of the resistors which resulted in a new current limit of 0 46A Despite this increased current limit there was a noticeable drawback in the overall protective operation While normal overcurrent protection functionality would operate normally after reconfiguration the same could not be established for the differential current protection elements With differential protection enabled and appropria
51. iguration elements to be configured without generating errors The calculation of the TAPn Per Unit value element was required to be completed manually as described in section 6 2 3 Differential Protection However with the variables entered to identically match those of the simulation the results were significantly outside the permissible configuration range 0 1 6 20 TAP To overcome this issue the CT ratios used in the calculations were increased by a factor of 10 to reduce the final calculation of TAPn to an acceptable level At this point the O87P element Restrained Element Operating Current PU as a multiple of TAP was set to the maximum and the differential protection functionality was disabled to allow operation and obtain the nominal differential metering data through the Differential HMI window At this point it was found that even with the modified calculations the differential metering values showed that the system was operating beyond a configurable level the O87P element has a configuration range of 0 1 1 PU while the measured data reported 1 32 or higher PU as shown in Figure 30 47 Nicholas Kilburn Device Overview S S Phasors Differential Metering Values Fundamental Min Max SEL 787 Date 26 11 2013 Time 10 09 53 rg TRNSFRMR RELAY Time Source Internal ea oar is IOP1 IOP2 IOP3 hr Operate pu 1 32 2 32 1 32 Energy Metering RMS IRT1 IRT2 IRT3 Thermal Restraint pu 1 35 1 35 1 35 Math Variables Analog Inputs I
52. ing better demonstration of the operable functionalities that the relays can provide Currently the resistive load module available 51 Nicholas Kilburn with the Lab Volt system resulted in a fairly heavy operating restriction on the final simulation in terms of limiting the variety and magnitude of faults being introduced Acquire a collection of better rated hardware transformer contactors relays etc to develop a higher powered and standalone system which can replicate the functionality provided through the Lab Volt system whilst doing so at higher power ratings This will allow a more realistic and self contained simulation to be developed and improve the overall operation of the simulation and its protection capabilities Acquire a wider range of CTs with various ratios to help develop a more ideal simulation that is particularly beneficial to differential protection In differential protection it is desirable to have CTs that result in identical secondary currents to allow easy and ideal configuration and operation of differential protection The current mismatched CTs result in a differential protection system that under nominal operation has a significant difference in currents between the primary and secondary windings once the relay measures the currents The calculations account for a variety of factors but can t eliminate the impact of mismatched CT ratios Acquisition of a non isolation type faultable transformer will imp
53. ing short circuit fault event confirming the ideas presented by Edmund Schweitzer 16 as mentioned previously and confirming a successful simulation configuration Figure 29 illustrates the event summary for the negative sequence 50Q trip event and provides verification the event being identified as Wdg1 50Q Trip that the desired response was obtained during a line to line fault This summary doesn t contain the metered negative sequence component however it does give an indication that both contactors would be tripped and shows the variations in primary and secondary phase currents at the time of the fault 46 Nicholas Kilburn gt gt sum SEL 787 Date 26 11 2013 Time 09 29 34 406 TRNSFRMR RELAY Serial No 2009300461 FID SEL 787 R202 V Z001001 D20100215 CID 53A1 EVENT LOGS 20 Event Wdg1 5 Q Trip Targets 11010000 Freq Hz 58 8 Winding One Current Mag TAW1 IBW1 Icw1 IGw1 A 1 6 2 9 1 7 0 00 Winding Two Current Mag TAW2 IBW2 Icw2 IGW2 A 1 4 E 3 6 0 02 gt gt Figure 29 Negative Sequence Trip Event Summary The negative sequence protection response to phase load removal prevents the residual current protection elements from responding This has been tested and confirmed by configuring the residual component during the previous negative sequence fault simulations 7 5 2 Differential Protection The simulation of differential protection required some cheating to allow for the conf
54. ion in the event of a dropout of local AC voltage inputs where there is no corresponding changes in current signals REF Restricted Earth Protection against internal ground faults in wye Fault transformers AFD Arc Flash Detector Fault protection against internal switchgear arcing Table 2 Letter Variations Variant Definition Extra details P Phase Phase based protection G Ground Residual Type dependent upon CT VT availability Q Negative Sequence Reverse Phase Rotation protection N Neutral Neutral Current Detection Similar to RCD protection principles R Rate of change protection against frequency instability by initiating load shedding RF Aurora Mitigation frequency based protection in detecting islanding S Synchronism localized application of function 25 11 2 Nicholas Kilburn 3 2 Monitoring Functionality There is an assortment of various monitoring metering and relay protective functionality which are common to all the relays available in the SEL Protection and Monitoring System Table 3 lists the common or standardised functions All of these and others which are unique to specific relays are configurable through the AcSELerator Quickset software package from the relay s front panel or through remote network communications based commands Table 3 SEL non ANSI IEEE features Name Details Password Protection Prevention of unwanted operation or
55. is internally faulted or to protect against consecutive reconnection transients damaging the transformer if the fault is still present The manual reset enforces inspection and fault analysis before circuit breaker closure is attempted thereby ensuring it is safe to proceed with re energizing the transformer 152 Nicholas Kilburn 4 2 Secondary Relays Figure 7 Secondary Relays 4 2 1 SEL 311L Line Current Differential Protection and Automation The SEL 311L Line Current Differential Protection and Automation Relay is a three slot rack mountable protection relay designed for current differential protection of long distance transmission lines This is achieved through the integration of fibre optic communications to allow coordination and interaction with another SEL 311L monitoring the breakers at the opposite end of the transmission line Specific protection functions provided include 21 25 50 51 67 79 81 and 87L and monitoring functionality include Breaker Wear monitoring Battery monitor Oscilloscope event recording and Fault Locator capabilities The majority of functionality available within the SEL 311L is also available through the three primary relays to some extent The exception is the communications based differential protection capabilities However a secondary unit would be required to properly demonstrate this functionality The SEL 311L is the second relay from the top shown in Figure 7 4 2 2 SEL 351 Dir
56. itoring communications it can provide Investigations need to be made into configurations that allow the device to simultaneously communicate and receive monitoring data from all the relays If enough of the proper Db 9 type cables are acquired then the 3351 can be used to easily program all relays simultaneously through proper networking configuration via the device manager functionality of the AcSELerator Quickset program Currently the program is installed on a flash drive connected to the device but the on board memory is fairly limited which restricts installation of the program directly One possibility before commencing this course of action is to investigate the possibility of obtaining a replacement updated model The current 3351 operates with Windows XP which encounter the potential security risks when Microsoft drops all support and security updates in the near future This will be an issue if the monitoring and control configuration is to be established through a TCP IP network 9 4 Protection Functionality 11 Incorporate Time Overcurrent elements into the developed simulations the benefits of developing a coordinated protection system may be more observable when a larger simulation is developed better demonstrating the protective benefits 53 Nicholas Kilburn 9 5 cDAQ Potential 12 There is a potential for using the cDAQ with the SEL Protection and Monitoring System the cDAQ has the most potential when used with th
57. itoring functions detailed in Table 3 in section 3 2 Monitoring Functionality are as already stated common to all the relays featured both Primary and Secondary The entirety of this chapter contains details into the design of the relays and their associated functionalities 4 1 Primary Relays Figure 6 Primary Relays 4 1 1 SEL 421 Protection Automation Control The SEL 421 Protection Automation Control Relay is a three slot rack mountable protection relay designed for high speed transmission line protection it is the top most relay shown in Figure 6 above This relay features single and three pole tripping with reclosing control circuit breaker monitoring and failure protection series compensation logic and automation programing logic The relay is capable of 13 Nicholas Kilburn providing the following functions 21 25 49 50 50BF 51 67 68 and 79 To achieve this the relay features two sets of three phase CT and VT inputs 16 digital outputs and 15 digital inputs and communications is supplied via three 9 pin D sub connectors two fibre optic ports and an IRIG B BNC connector From the available digital I O 8 of the digital outputs available in slot 1 offer NO or NC contacts while the remaining 8 available on slot 2 provide NO high speed interrupting outputs The appropriate configuration of the available inputs and outputs allow control and monitoring of attached circuit breakers The SEL 421 can be progra
58. l causing CRn C to close resulting in the coil staying energised the result of directly connecting A to C until the reset button is triggered CRn A and CRn B provide the normal relay contact outputs to control the status of the three phase contactors and report the status back to the SEL 787 inputs for monitoring Figure 23 Physical Control Relay Connection 38 Nicholas Kilburn O 203 D OO zu os OH 0 205 os OH zes N 03 Interconnection Panel A Figure 24 SEL 787 I O Connection Diagram Figure 24 illustrates the connections via the interconnection panel to the SEL 787 relay I O connectors where connections Ao5 to Ao8 are the output terminals responsible for latching the control relays and Ag to A12 provide the inputs for status monitoring Figure 25 displays the complete Transformer Protection Simulation as developed using the Lab Volt equipment visually identifying the configuration and connections including the interfacing of the control relays and eventual connection to the SEL 787 relay through the interconnection panel 39 Nicholas Kilburn rocoso H AA P e Kir e Figure 25 Physical Transformer Protection Simulation System 7 3 Design Considerations Throughout the design and testing of the transmission protection simulation system there were several issues that needed to be considered that could limit the operational levels of the simulation
59. lation 6 1 Familiarization The first component of the investigation was familiarisation This involved simply exploring the system and attempting to replicate and understand the previous works conducted One significant aspect to this was recreating the LabView program previously developed which was the direct result of the program utilising an additional toolkit the Electrical Power Design suite as a trial version The initial program was working towards simulating the network shown in Figure 1 featuring a HMI window detailing the relay connections and their metering data as simulated by the cDAQ This program was designed to simulate the network elements and replicate the circuit breaker status However the attached relay SEL 421 had not been programed to respond to faults and the LabView program was not configured to introduce network faults This investigation yielded significant inroads into how the relays monitor the network elements and allow control of the associated circuit breakers At this stage the program would simulate network conditions and simulate the operation of the circuit breakers This simulation was to be removed from the final simulation platform following the significant discovery detailed in section 6 2 Significant Findings The remaining aspect of this stage of the project involved the detailed study of the relays and software manuals in conjunction with the appropriate relay software exploration which determined
60. ler functionality adds to the programing configuration and development requirements compared to the adjustment of dials or relay selection for the protection function e Relays require their own dedicated power source The microcontrollers require a dedicated power supply to maintain monitoring and protective functionality If the relay loses power their operational protection is lost e Significant transition process significant time and cost is required to successfully migrate from analog to digital relays inclusive of relay cabinet refitting updating required drawings and configuration time e Inability to operate effectively or accurately as designed in harsh conditions such as high temperatures severe environmental conditions and in high EMI or RFI prone areas Some of these disadvantages are the main driving forces behind old mechanical relays being replaced by newer non digital models simply because there is not enough knowledge of digital relays to install configure and operate or the installation environment won t permit the installation of digital relays Evidence of this can be seen through the new installations of GE designed protection relays in Canada where 40 of these were still electromechanical based systems 4 Figure 5 is an example of a digital protection relay developed by an alternative competing company to SEL as a point of comparison to illustrate visually the differences in relay design and implementation and d
61. maining relays 351 311L and 387E only the indicators are changeable the pushbuttons available provide a mechanism to navigate the operations available through the front panel display where various relay functionality can be controlled modified or monitored 6 2 7 2 Automation The automation logic is a separate set of logic equations up to 1000 lines of code fully user programmable and not functionally tied to any particular function within the relays The automation logic also exists separately to any variables and math functions available within the relay The programing of the automation logic is entirely up to the user with respect to the interfacing of relay words metering data the status of I O words and any communications received The programming is free form where the intended target of the equation or function is user definable and can be a math variable or operable relay target The relay uses Aliases to allow this free form logic to be associated directly to relay word bits without modifying the traditional functionality of the associated relay word bit Figure 18 illustrates an example of the free form programing which is typical of that used to program the automation logic The 31 Nicholas Kilburn example shows the configuration for the interlocking of the functionality associated with several of the front panel pushbuttons Protection Free Form Logic Settings PROTSEL1 PROTSEL250 1 PLTO2S PB2_PUL AND NOT
62. me lower burden longer lifespan bounce less operation lower electrical noise and improved sensitivity to operational environment impacts vibration humidity etc However the following disadvantages also exist which prevents their widespread adoption influenced by transient events causing undesired operation and having a high resistance when closed which generates heat and results in a non linear voltage current characteristic which impacts performance Figure 4 below is an example of a Solid State protective relay available as part of the Lab Volt Protective relaying system The three CT inputs are shown at the top potentiometers for setting trip level and time delay are in the middle and at the bottom are the relay contactor outputs with the auxiliary power supply connections Amps Seconds 18 ae LN 14 41 Figure 4 Three Phase Overcurrent Relay Nicholas Kilburn 2 3 Digital Relays Digital relays unlike mechanical relays use microprocessor technology to detect and respond to trip conditions Like other forms of protection relays digital relays measure the secondary elements but convert these to a digital form for the microcontroller to process and respond in the event of a fault Being a digital based fault calculation process digital relays emulate the protection functionality and are thus able to emulate multiple protection functions through the one unit As an example a base overcurrent protection digital rel
63. med with two outputs one to signal open commands and the other to send close commands while one input is used to monitor the status of the circuit breaker Monitoring functionality that is unique to the SEL 421 includes dual circuit breaker condition monitoring station battery monitoring fault locator transient overreach load encroachment monitoring oscilloscope type monitoring and metering capabilities and extensive user programed automation logic The automation logic is programed using SELogic equations to allow user required functionality to be automatically enforced under the required conditions This can include the communications based tripping of other upstream relays automatic report generation and transmission to a local database or the activation of external alarm outputs not normally tied to fault event conditions within the standard relay configuration With the use of SELogic to program the automation functions the user can define any number of conditions that would be required before the automation function can be activated This can include specific pickup levels and the current status of relay I O or internal target or the contents of communications from upstream downstream relays metering information fault data or the status of relay targets 4 1 2 SEL 751A Feeder Protection Relay The SEL 751A Feeder Protection Relay is a six slot I O expandable protection relay shown in the bottom right of Figure 6 It is designed t
64. monitor functionality where the operation of the breaker will trigger a count up event This number can then be compared to operation limit variable to alert to when the life cycle of the breaker has been reached The counters can be programed to monitor a wide variety of relay words targets to indicate the occurrences of status changes e Math variables allow for the storage of real non Boolean type data mostly required for metering data This can be utilised to allow metering data to be communicated over networking or to display data that the HMI or communications reports wouldn t normally generate 32 Nicholas Kilburn 7 Simulation Development The simulation development phase of the project where hardware was compiled and designed to demonstrate the available functionalities of the SEL protection Relays This chapter focuses on the significant pieces of hardware and the uncovered design considerations necessary to produce the final simulation platform The final simulation platform was restricted to transformer protection using the SEL 787 Transformer Protection Relay This restriction was the result of limited hardware availability and time restrictions caused by the early cDAQ simulation focus Original simulation design considerations included the acquisition and construction of a custom made set of components to allow a suitable simulation to be developed To fulfil this task a three phase variac single phase variac and
65. monitoring functionality and additional I O to meet other application requirements The majority of protective functionality on offer is also provided in some form by the three primary relays with the exception of the 3 winding transformer current protection 4 2 4 SEL 3351 System Computing Platform The SEL 3351 System Computing Platform is an Embedded PC running Windows XP that provides a variety of monitoring advantages It is the bottom most device shown in Figure 7 The 3351 relay has the following features e 16 9 pin D sub connectors permitting up to 16 SEL relays to be simultaneously interconnected providing a common access point interface to each relay e The 3351 has its own display keyboard and mouse connectors to locally monitor configure or control any relay connected on a local network or directly to the D sub connectors e RJ45 Megabit network port allowing internet connectivity that permits a remote connection to the device s windows environment and thus to any connected relays e Two fibre optic ports for long distance system communications e 4 USB ports for connecting of external storage drives keyboard and mouse These features benefit the system user both local and remote by providing a single point of access to all the features and functionality of the connected relays within the protection system 170 Nicholas Kilburn 4 3 Modularity All relays available are rack mountable with the technical exc
66. mpensation Restricted Earth Fault T GE Overcurrent Elements Time Overcurrent Elements VWDG1 Winding 1 Line to Line Voltage kV O RTD 138 00 Range 0 20 1000 00 Under Over Voltage Elements V Hz Elements Power Elements Frequency W2CT Winding 2 CT Connection Demand Meter WYE y Select DELTA WYE Trip and Close Logic Logic 1 CTR2 Winding 2 Phase CT Ratio Graphical Logic 1 1 Range 1 5000 Group 2 Group 3 W2CTC Winding 2 CT Conn Compensation Group 4 2 Range 0 12 Front Panel O Report VWDG2 Winding 2 Line to Line Voltage kV e Ge a 13 50 Range 0 20 1000 00 O Por Pot Pat CTRN1 Neutral IN1 CT Ratio Port4 120 Range 1 5000 Modbus User Map DNP Maps one 120 00 Range 1 00 10000 00 VNOM Protected Winding L L Voltage kV 13 80 Range 0 20 1000 00 DELTA_Y Potential Transformer Connection DELTA Select DELTA WYE VIWDG Voltage Current Winding 2 Select 1 2 COMPANG Compensation Angle Deg o Ranne 0 260 x Part 07870X1A0X0X0X810830 Group 1 Configuration TXD ma RXD Es Open Connected COM1 Communications Port 9600 8 None 1 Terminal EIA 232 Serial File transfer YModem Settings RDB Figure 15 Settings Editor 787 The Settings editor is the most important component of the AcSELerator Quickset software package as it provides the mechanism to allow easy programing and configuration of the connected relay Once the connection has been established to the relay
67. ntial metering communications The disappearance of the required relay to relay 9 pin D sub cable and time constraints prevented the testing of the Mirrored Bits communications integration of the SEL 3351 and other relay to relay communications a functionality that would be highly beneficial in integration of a variety of local substation based relays for total protection and automated tripping protection Again the absence of fibre optics prevents the high speed operation capabilities that some of the relays can provide through communications 6 2 7 Configuration Capabilities Besides the ability to configure the protection elements of the relays there are other beneficial configurable components of the relays 6 2 7 1 Front Panel On the SEL 421 751A and 787 the front panel items buttons indicators and controls are user configurable allowing the buttons to control whatever relay functionality the user requires while the indicators can be changed to indicate the status of any required elements targets As an example the Open Trip button on any for the relays could be re configured to directly control the status of the Trip target element rather than control the status of the circuit breakers Of these three relays the SEL 421 and 787 allow the labelling of the buttons and indicators to be changed to reflect the function or element being controlled or monitored while the SEL 751A labels are not removable or changeable For the re
68. nts and any other necessities for successful operation e Develop improve a suitable simulation platform be it LabView or physical hardware based of a basic power distribution system that can demonstrate the operational functionality of the available SEL protection relays e Produce documentation that details the processes required to design program and operate simulations that demonstrate desired functionalities Kb Nicholas Kilburn 2 Protection Relays 2 1 Purpose The protection of power distribution systems is and always has been a critical element in maintaining a stable network for power generation transmission and consumption Protection Relays allow the integrity of the distribution equipment such as transformers generators and transmission lines to be maintained to a high operational standard improving supply and reliability and achieving almost 100 availability of electrical power to consumers Protective Relays provide protection from fault events by opening circuit breakers which isolate the equipment from the fault the relay will also trip the circuit breakers if the equipment is the cause of the fault thereby protecting the network from damage The relays constantly monitor the necessary network elements including Current and Voltage and occasionally temperature or harmonics among others The implementation of these relays depends upon the protection function and the equipment that needs to be protected The
69. nts remained enabled and configured from previous simulations to again provide a realistic operating simulation despite reducing the means to allow development of differential trip event Under these conditions the differential elements would assert when the power supply was increased and the transformer windings were shorted The remaining faults resulted in phase overcurrent faults Figure 31 contains the event summary for the increase in power supply induced fault showing both the primary and secondary currents increasing which caused an increase in the differential elements being measured This change can be observed in the event report generated through the use of the command EVE DIFn n being the required phase 1 2 or 3 which has 48 Nicholas Kilburn the same result as the EVENT but includes the differential metering data for the numbered element set An example of this output can be observed in Appendix 12 3 gt gt sum SEL 787 Date 26 11 2013 Time 09 54 59 778 TRNSFRMR RELAY Serial No 2009300461 FID SEL 787 R202 V0 7001001 D20100215 CID 53A1 EVENT LOGS 32 Event Diff 87 Trip Targets 11100000 Freq Hz 50 0 Winding One Current Mag IAw1 IBW1 Icw1 IGW1 A 1 1 1 1 1 1 0 00 Winding Two Current Mag TAW2 IBW2 Icw2 IGW2 A 1 5 1 5 LoS 0 02 gt Figure 31 Differential Event Summary There were occasions during differential configuration where the initial configuration of the CT ratio alone wa
70. o provide current protection to distribution feeders and localized power equipment The relay provides the following functionality by default 50 51 and 81 while the following is available through the installation of additional I O cards 25 27 32 59 60 79 Arc Flash Detection and RTD based protection The default relay configuration provides 4 CT inputs 2 inputs and 3 type C outputs NO NC two RJ45 connectors one fibre optic port and two serial RS 232 connectors There are two expansion I O cards installed providing 4 digital inputs 4 digital outputs 4 analog inputs and 4 analog outputs which results in a majority of the optional protective functions becoming available The main functional advantage of the 751A relay within the three primary relays is the existence of the Neutral CT connection that allows direct measurement of neutral currents thereby optimizing residual current protection and detection of faults 14 Nicholas Kilburn 4 1 3 SEL 787 Transformer Protection Relay The SEL 787 Transformer Protection Relay is a six slot I O expandable protection relay that is visible in the bottom left of Figure 6 This relay offers current protection functionality targeted specifically for transformers The relay provides the following functionality by default 50 51 87 and breaker failure protection with the following available through the installation of expansion I O cards 50 51N 24 27 32 59 60LOP 81 and REF prote
71. on elements can be enabled without causing undesirable trip conditions This process has pickup elements which are set in multiples of TAP which if the system is ideally configured balance CT ratios then this pickup level could remain at the lower end of the configuration range improving operation response times 6 2 4 The Relays Some specific aspects of the relays suggest that the system is composed of a collection of spares or outdated devices Facts such as the varying power supply requirements the apparent manufacturing dates and the indication that some devices have been replaced updated or superseded support this theory The serial numbers of the relays tend to indicate the date of manufacture with the oldest relay originating from 2007 The datasheets available from the SEL website and list of available relays suggest that a couple of the older relays have undergone significant updates notably the SEL 351 is now referred to as a Protection System 13 while others such as the SEL 3351 no longer exist in the product catalogue although this could be attributed to the impending phase out of Windows XP via Microsoft 14 6 2 5 Switching Requirements For some of the relays the I O switching pickup levels can be configured within AcSELerator Quickset to suit the magnitude of the voltage source being supplied to the relay or to meet the requirements of the device receiving the outputs The SEL 421 is an example of this where the cDAQ was
72. or Quickset Home The software package AcSELerator Quickset is the primary mechanism for communication programing monitoring remote control and metering of the SEL relays as part of the Protection and Monitoring System The program is currently installed on the associated Windows 7 PC and on a USB Flash Drive connected to the SEL 3351 to allow the device to communicate with the relays Figure 10 illustrates the initial start up window where a new settings file can be created Settings can be read from the connected relays Previously saved settings files can be opened from the local database Any connected devices can be managed using port addresses unique names remote connection settings etc or communications parameters can be modified by selecting any of the available options All settings control or communications operations require an elevated operation security level often level 2 this can either be entered into the communications parameters through the tools drop down menu or entered upon each initialisation of communications The current common requisite passwords are included in Appendix 12 1 202 Nicholas Kilburn 5 1 Command Window ACC Password 2 SEL 751A Date 18 11 2013 Time FEEDER RELAY Time Source Internal Level 1 gt id FID SEL 7514 R402 Y0 Z006003 D20100129 08E7 BFID BOOTLDR R500 Y0 Z000000 D20090925 0952 CID 7ADE 027E DEVID SEL 751A 0408 DEVCODE 69 0316 PARTNO 7
73. r Power Supply Supply 48 125V DC Rated 45 125V DC 120V AC 50 60Hz 125V AC 50 60Hz Burden 40W Burden lt 25W Range 38 140Vdc 85 140Vac Range 38 200Vdc 85 140Vac 63 9
74. rated in Figure 2 showing all the relays mounted in their enclosure and the associated PC with required AcSELerator Quickset software installed in the Project Room Not visible is the cDAQ power supplies and I O terminals which are accessible from the rear of the retrofitted IP network server rack Figure 2 SEL Protection and Monitoring Rack 1 2 Purpose The SEL devices are intended for protection of high voltage distribution networks and all equipment types including transformers bus bars feeders etc As such they offer a wide variety of different protection functionalities which in some cases are quite complicated Having a limited knowledge of the functionality and the requirements wiring programing and commissioning to achieve this functionality makes the development of a suitable distribution protection simulation difficult and nearly impossible to achieve 20 Nicholas Kilburn 1 3 Objectives The Primary Objective of this project is to continue on from the works conducted in ENG454 to develop a comprehensive understanding of the SEL devices to allow development of a suitable simulation platform to demonstrate the functionality that the SEL protection devices are capable of providing This is to be achieved through the following steps e Acquire a comprehensive understanding of the available SEL protection equipment including functionality programing requirements physical hardware wiring and power requireme
75. relays measure the network elements current and voltage through step down CT s and VT s and their operations are based upon the secondary magnitude which allows the relays to be of a manageable size and achieve the quickest possible operating time The relays will trip the circuit breakers when the monitored elements reach a pre set value indicative of a potential fault event thus protecting the equipment from the damages that could result if the fault persists 2 2 Analog Relays 2 2 1 Electromechanical Traditionally Protective relays are an analog type electromechanical device designed to measure and calculate network nominal operation conditions and to trip circuit breakers thereby disconnecting the network when a fault is detected These electromechanical relays have well defined and selectable operation parameters based upon the protection function to which the relay belongs These relays operate directly from the current and voltage signals being supplied and converting these into electric or magnetic forces torques via electromagnetic coils which acts against internal springs to open the relays The configuration of these relays is conducted by adjusting the tension of the spring and or taping of the electromagnetic coils thus changing the trip characteristic of the relay Mechanical relays in general have developed a reputation of being highly accurate dependable and reliable 2 Figure 3 shows an example of a traditional electrome
76. required resetting before simulations could resume 43 Nicholas Kilburn 7 5 1 Overcurrent Protection 7 5 1 1 Phase For the Phase overcurrent protection simulations the associated elements were the only ones to be enabled and were configured for instantaneous operation type 50 For these simulations the pickup settings were set to 10 higher than the nominal current for both the primary and secondary to ensure Lab Volt equipment resistive load module wasn t exposed to high currents for a prolonged period The low fault levels produced during testing also justified the use of a small margin However ideally margins in the range of 50 are often desirable to prevent low level tripping due to network fluctuations For the majority of the faults induced line to line winding short circuit phase load removal the response resulted in the primary side contactors being tripped This is evident by the front panel display of the SEL 787 as shown in Figure 26 after a transformer winding short circuit fault event was introduced The one exception to this was the introduction of an overcurrent event through an increase in the power supply voltage where despite the relay response indicating initial fault being detected on the primary winding CTs both contactors were tripped as analysis of the fault event summary showed both primary and secondary currents had exceeded pickup levels causing the relay to trip both primary and secondary cont
77. rove simulation relevance an applicable demonstration The isolation type transformer used in the Faultable Transformer module has a turn s ratio of 1 1 resulting in un realistic simulation circumstances and preventing a differential current across the transformer under fault conditions This is why the Delta wye configuration has been used so that there is a natural adjustment in voltage and current seen between the primary and secondary windings The use of a transformer with a non isolating type turns ratio will help to improve the demonstration of differential protection The fact that the simulations conducted were at similar voltages primary and secondary added to the complications experienced during the configuration of the differential elements 9 3 SEL Relays 7 Further investigate the operable functional capabilities and develop appropriate simulations of the SEL 421 and 751A the completion of which will allow for an understanding of the majority of protective functionality the SEL Protection and Monitoring System provides Paying particular attention to the voltage and power based protective functionality of the SEL 421 features that haven t been deeply assessed during the transformer protection simulation resultant of the availability of current based protection only with the relay Regarding the SEL 787 the acquisition of expansion I O cards should also be considered Doing so would expand the protective functionality to the point
78. rsity Mr lafeta Jeff Laava Mr Will Stirling Mr John Boulton Technical Officers Murdoch University And fellow thesis students family and friends for their support assistance and patience throughout the project Nicholas Kilburn Contents ABSTRACT E I ACKNOWLEDGEMENTS ooccoccococcoccncoccnncnconconcoroncoccoronconcoronroncnronroncnronconcnronconcronconcnronccccncones TI LIST OF FIGURES sissies sscscescsscsccscescactacsscscdacescstescssescdssescecescasesccscssesteseseesciecesesceasseescvacsoesce VI LIST OR TABLES E VU LIST OF EQUATIONS EE VII 1 PROJECT INTRODUCTION csccsscescsccscescsccscescsccscesceccscesceccscescscescescecescescecessessecenes 1 1 1 BACKGROUND EE 1 1 2 A ET EEE TER 2 1 3 Be KE 3 2 PROTECTION RANNER RENE ENEE EENS KEEN ENEE ENEE ou A 2 1 PURPOSE gege e EES A 2 2 ANALOG RELAYS ss senveisheibveatsenevesveadhvsubscnevousecdhvsutacarsssoeadey ssdscuevocesedovecdeceovereeeduvects sa RS EE EEEE PESER 4 2 2 1 ett EH Een a E a a EA ANE N NE RS 4 3292 SOM SE aE este ee 6 323 ICA EE 7 2 4 SCHWEITZER ENGINEERING LABORATORIES IN 9 3 SRELAY FUNCTIONALITY asien ee Edge ehe ersehen 10 3 1 PROTECTION FUNCTIONALITY osss acoisscucvsdessentetensntevcensuatsdenshtdevendaniecencelvovensuohecensedvodonshole deesesVodnnsaehetensves 10 353 MONITORING FUNCTIONALITY s cccisccdssce tice econo anida Aaa 12 4 SEL UNITS OVERVIEW vesscssecesscsessescaceesescciecsnscconssedscteacedscdeccesccdeccasccosecesc
79. s enough to generate errors when attempting to download new settings regardless of whether the differential elements are enabled or not The cause of this is the existence of the automatic calculation function associated with the configuration of the differential elements combined with the relays inability to ignore disabled elements during settings download Even when the differential functionality is disabled the auto calculation still computes and with the non ideal simulation configuration the eroded calculation for TAPn is still generated causing the initial errors The solution is to enable the differential functionality to permit changing of the configuration then reduce the TAPn elements to acceptable bounds and adjust any other elements that will result in the generation of configuration errors Once that is completed disable the differential functionality then initiate the download process This should now complete without error allowing operable testing to begin The issue with the existence of the auto calculation is that every time changes to the CT configuration are made CT ratio nominal voltage if available and CT connection the calculation will compute causing download errors The errors produced are exaggerated by the inability to change the nominal line voltage settings which are disabled the moment a change to the MVA setting is made resulting in auto calculations always being erroneous Even in the event that manual calculation settin
80. s history along with providing a means of manual control over the relay controls e Reporting event report generation containing critical event data measurements statuses etc e Self testing internal checks for failure of relay systems from internal memory to I O contacts in element inputs e Alarming automated alerts to faults relay failures or undesirable operation conditions Besides the improvements in functional operation and availability the microcontroller systems provide more generalized advantages to digital relays including e Increased accuracy reliability and a reduced expense per functionality 4 e Smaller size and significant reduction in cabinet space per protection function ye Nicholas Kilburn e Modular layout and upgradability that allow for easy replacement or expansion as functional demand increases or changes over time e Software interactions providing a gateway for programing monitoring and control e Smaller burden on the CT s or VI s when compared to electromechanical relays as digital relays do not use the signal from the signal transformer secondary to drive the internal tripping circuits thus reducing the applied load However as with many technological advances there are some disadvantages that need to be noted e Increased configuration complexity the transition from analog to digital combined with the consolidation of protective functions and addition of microcontrol
81. secesecesecesecssecssecseecssecsseceseceeeceeeceneceaeenseeneees 39 Figure 25 Physical Transformer Protection Simulation System EE 40 Figure 26 Fault event SEL 787 Front Panel csccssscssscesccssecssecesecesecssecssecssecssecsaeceseceeeceeecsneceeeenseceaeeaes 44 Figure 27 Fault Event Summary ii A Brennen nn inne 45 Figure 28 Residual Trip Event Summary cccssssssscescesseseeecceceeseeeeceececeesseeaceeceneesaseceeacenesseeeaseaeeaseeateeees 46 Figure 29 Negative Sequence Trip Event Summarg EEN 47 Figure 30 Initial Differential Metering HMI ue 48 Figure 31 Differential Event Summary ccscsscssscssscesssssscessssssessscesscssseesseesscssscesssesseesseeseeesseesssesscesseeses 49 Nicholas Kilburn List of Tables Table 1 Available ANSI IEEE Protection Functions ENEE 10 EIA Ee EE 11 Table 3 SEL non ANSI TEEE features ssccsccssesssscssssssssseccsocesstssscossosenstsssecssasssstecssnseassssseossceessesssess 12 Table st TAPn Calculatons 20 aka ren Rene ande tiere de 48 List of Equations Equation 1 Secondary Impedance Ratio fil 28 Equation 2 Secondary Impedance Calculation Il eessen 28 Equation 3 Source Impedance Ratio fol 29 Equation 4 Differential Element Configuration Equation T 29 Nicholas Kilburn 1 Project Introduction 1 1 Background Currently at Murdoch University within the Project Room of the Engineering and Energy Building
82. t shows the data transmission of metering data to operate the HMI Phasors Window 25 Nicholas Kilburn gt gt 1 lt JT gt BH gt gt k BJT z gt GoBH 4 cP w P BHIT i gt S Niv n 8BH gt t u BJT gt 9 RBH O gt t f1 gt CME TA MAG IA ANG IB _MAG IB_ANG IC_MAG IC_ANG IN_MAG IN_ANG IG_MAG 0 1 0 0 0 0 144 2 0 1 166 3 0 3 94 2 0 1 139 8 098D IAV 0150 0 1 00BB 312 UBI 026E 0 1 0 0 0175 FREQ O19E 50 00 011F gt CME TA MAG IA_ANG IB_MAG IB_ANG IC_MAG IC_ANG IN_MAG IN_ANG IG_MAG 0 1 0 0 0 1 106 3 0 0 116 6 0 1 169 7 0 1 57 1 0901 IAV 0150 0 1 00BB 312 UBI 026E Figure 17 HMI Communications Impact 26 Nicholas Kilburn 6 Relay Investigation The relay investigation process was a significant component of the overall thesis as was the achievement of the final simulation outcomes This process yielded all the necessary details regarding the relays the means to program and the capabilities available through accurate configuration the details of which have been covered previously However this process also yielded some significant discoveries some which prevent many of the functionalities being demonstrated while one in particular changed the direction of the project most notably the change from a full Lab View cDAQ based simulation to a completely hardware based simu
83. te configuration of the higher operation current available both primary and secondary caused undesirable differential trip events under nominal system operational conditions which were caused by the non ideal CTs and natural current differential of the Delta Wye transformer used The higher operational current available through using the motor causes a greater current differential across the transformer which is further exaggerated by the CTs preventing easy configuration of the differential protection element With the knowledge that the resistive load provides a more suitable operating condition resulted in the motor being removed as an alternative solution 7 3 4 Type 68 Lockout Relay The absence of a required type 68 lockout relay for the SEL 787 was another design consideration To account for this absence the latching relays were utilised whereby the pushbutton provided would replace the reset operations the SEL 787 would normally control The main reason this was the case was the pulse output nature of the 787 where the relay would not maintain a constant output throughout the occurrence of a fault trip condition 7 3 5 Earth Leakage Circuit Breaker The existence of the earth leakage circuit breaker on the three phase power supply within the room was a significant operations consideration The presence of this circuit breaker would prevent ground fault simulations from being conducted due to the low pickup current of 30mA The existen
84. te the current in terms of Current Tap TAPn as shown in Equation 4 and utilised in the configuration for transformer differential current protection Equation 4 Differential Element Configuration Equation 12 MVA x 1000 TAPn _ _ x V3 xVWDG xCTR Where e C 1 for wye or V3 for Delta e MVA Maximum transformer power Rating e VWDG Line to line winding voltage kV e and CTR CT ratio setting If these elements are correctly entered in the configuration window then this equation is automatically calculated accounting for any current imbalance that would occur from a phase shift within the transformer thus allowing pickup levels and other configuration elements to be entered without the development of errors which can make this process pain free assuming these values are realistic 29 Nicholas Kilburn Problems with this process arise when these configuration elements are set to abnormally low MVA line voltages and CT ratios causing large configuration errors for the differential elements so that the nominal voltage input fields become inaccessible and the MVA field reverts to its off state If the MVA field is set to off this calculation can be done manually and the differential element configuration process will then need to be completed by the user adjusting each field to satisfy the various limitations imposed by the relay If this process is completed correctly then the differential protecti
85. tection against voltage sag or dropping network voltages Relay within present bounds 32 Directional Power Two way protection against overload or reverse power Relay 49 Thermal Relay Protection against abnormal temperatures 50 P G Q N Overcurrent Relay Protection against abnormal high currents or fault conditions 51 P G Q N Time Overcurrent Time overcurrent protection coordinated relays TOC curve Relay 52 AC Circuit Breaker AC circuit breaker opening contactors in a network 10 Nicholas Kilburn 55 Power Factor Relay Protection against undesired power factor conditions 59 SO Overvoltage Relay Protection against high network voltages 67 AC Directional Protection against phase to phase short circuits through Overcurrent Relay comparison to voltage waveform patterns 68 Blocking Relay Prevents tripping under certain conditions e g Out of Step 79 AC Reclosing Relay Auto reclosing relay for purposes of automatic reconnection of network if fault clears limitation of downtime 81 R RF Frequency Relay Protection against undesirable frequencies 86 Lockout Relay Latching type relay meaning constant control signals not required 87 Differential Protection against a differing current between to Protective Relay measurement points 50BF Circuit Breaker Protection against breaker failure by signalling upstream Failure breakers to trip if main failure occurs 60LOP Loss of Potential Protect
86. the relay has additional digital or even analog I O that is able to being programmatically tied to an alarm Relay Word or target to externally indicate the status of relay conditions elements or protection functions which aren t displayed on the front panel 6 2 2 Distance Protection There is a collection of functionality that requires specific hardware to enable proper and effective simulation development The notable function is the distance protection offered by the SEL 421 relay The protection function utilises the known impedances of the source line and load in order to determine which zone of protection the fault occurs and apply the required tripping response This function uses the impedance as a secondary value to determine the zone of operation for protection The secondary impedances are calculated through the following equations Equation 1 will determine the impedance ratio then Equation 2 will convert the known primary impedance into the equivalent secondary impedance Equation 1 Secondary Impedance Ratio 11 _ CTR PTR Where e CTR Current Transformer Ratio e PTR Potential Transformer Ratio Voltage Equation 2 Secondary Impedance Calculation 11 Z secondary K x Z Primary The zones can then be configured through multiplying the secondary impedance by the desired distance percentage reach The reach determines which tripping scheme and operation mode will operate based upon the measured impedance at the
87. the settings editor will open and allow configuration of relay words that relate to available functionality Figure 15 illustrates the settings editor for the SEL 787 relay with the group 1 set 1 configuration collection of relay settings open This window configures the CT transformer configuration and MVA and nominal line to line settings for the primary and secondary of the connected transformer The settings editor will display the available setting ranges or options next to the field to allow for easy identification and programing of the field and the associated configuration restraints An example is the CTR1 field in Figure 15 where the indication suggests that the possible setting for the CT ratio is between 1 and 5000 Also visible is the inability to modify some relay word elements e g CTRN1 Neutral CT ratio as the functionality that the relay word refers to is unavailable with the current version of the 787 relay The settings editor will have a different overall left column 24 Nicholas Kilburn structure based upon the connected relay and associated available functionality and configuration options 5 4 HMI AcSELerator QuickSet Devi J k File Edit View Communications Tools Windows Help Language o x G aadu as oo e2 eea alg Device Overview E m Phasors Device Overview Fundamental Min Max Metering Demand Device Current Peak IA 0 07A Een ic I ooa Synchrophasor a ae RMS IN 0 09A
88. tional operations and applications of the available devices This portion of the project yielded the required details about the scope of the protective functionality the mechanisms and requirements to program this functionality and the operation requirements This resulted in the construction of a hardware based Simulation platform provided through Lab Volt equipment demonstrating the functional capability of the Transformer Protection Relay The testing component provided a mechanism to ensure that the simulation and relay would demonstrate the available functionality as expected The simulation platform can be used to demonstrate the overcurrent and differential protection functionality along with providing an operable insight into the relay monitoring and metering capabilities Hardware limitations prevented a truly realistic simulation being developed and tested notably the low fault levels and restricted fault types available However the construction of this Simulator has demonstrated the acquired knowledge of the relays and provided the groundwork to extend the Simulator to incorporate further relays and protective functionality Nicholas Kilburn Acknowledgements Acknowledgements are given to the following for their assistance and guidance throughout completion of this project Project Supervisor Associate Professor Graeme Cole Lecturer Murdoch University Associate Supervisor Dr Greg Crebbin Lecturer Murdoch Unive
89. ult recorded in the relays event history This command provides the ability to display the metering data at time of fault indicating the system conditions and fault type that has occurred This command can also call older fault event data by using numeric numbers following the summary command e g summary 8 will display the 8th fault event summary recorded by the relay For a complete list of available commands see the associated relay instruction manual accessible through the university or within the AcSELerator Quickset settings editor environment through the help tab 220 Nicholas Kilburn 5 2 SELogic ULTRIP Unlatch Trip SELogic NOT 51P 1P OR 51G1P OR 51N1P OR 52A m Figure 13 SELogic Equation Field SELogic is the name given to the equation logic used to develop a large portion of the programing of the SEL relays within the AcSELerator Quickset software package It is a collection of programing functions including Boolean logic mathematical operations and triggering functions which combine to allow a simple and effective mechanism to program specific functional elements of the relays The SELogic equations can be directly entered into the field within the Settings editor Figure 13 or through the dedicated SELogic editor window Figure 14 accessible by using the button to the right of the field NOT pp OR 51G1P OR 51N1P OR 524 And Or Not D O WA IA e e a Double click or click and drag to add
90. ut and output terminals current measurement terminals and a collection of fault inducing switches or input connectors to induce a variety of faults The input terminals in the fault section of the module allow the second transformer T2 to being faulted by an external source to allow introduction of short circuits with a resistive element included FAULTABLE TRANSFORMERS ov Ta GH Pi gu O LA G s2 ov UT 6 ov URRENT SENSOR RATING 4000 240400 24 Y 120 VA 80 Ma 3 UNITS momo 0 8 A CONTINUOUS 1 A FOR 2 min Figure 19 Faultable Transformer Module 34 Nicholas Kilburn 7 1 2 Transmission Grid The Transmission Grid Module offers a collection of three phase contactors which can be controlled remotely via the available control relays or through the on board switches The three phase contactors provide a simulation mechanism for representing the circuit breakers that would usually be controlled by the protection relay Figure 20 shows the module that is currently available where the control relay interface visible in the bottom left corner The control relays are able to control the status of the three phase contactors through these inputs by energising the individual contactor coils Figure 20 Transmission Grid Module 35 Nicholas Kilburn 7 1 3 Universal Fault Module The Universal fault module contains an AC powered Pushbutton which activates a collection of intern

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