Nominal voltage on low voltage side………………value of the line
Contents
1. follows I equ 1 THD e Partial weighed harmonic distortion PWHD the ratio between the RMS value of a selected group of harmonics starting from the 14th weighed according to harmonic order n and the RMS value of fundamental current l Sa 1 S equ 1 THDY 23 232. of the offset angle between the voltage and the first current harmonic When a motor is operated by an inverter the total power factor is strongly dependent on the harmonic current i e on the current distortion factor Normally the power factor of a distorted waveform is defined as the ratio between the active power P and the apparent power VI also considering the contributions of all the harmonic contents Total power factor where Vk RMS value of the voltage harmonic k Ik RMS value of the voltage harmonic k q offset between the voltage harmonic k and the corresponding current harmonic In case of sinusoidal voltage and distorted current the total power factor is calculated with the following expression VI cos V gt 1 COSA Total power factor k 2 00 ADA k 1 When introducing the power factor distortion u that matches with the total harmonic current distortion THDI 21 23 GRUPPO CARRARO USER MANUAL Z SANTERNO EASY HARMONICS the total power factor becomes qe COS Py Ma Hu So the rectifier factor of the cose is given from k Errore Non si possono creare oggetti dalla modifica di codici di campo Example Suppose that an inverter connected to the grid by means of AC reactor only be used the typical current distortion value that is measured in that case is 50 i e 00 E S THDI u 50 ly So k 4 14 0 5 1 118 If a real unity cos is used the to
3. the following Nominal voltage on low voltage side Nominal voltage on low voltage side j 400 The no load voltage value of the LOW VOLTAGE SIDE in the mains transformer lt is expressed in Volts Nominal power of the transformer Nominal power of the _ transformer HH 100 kVA The nominal power of the grid transformer lt is expressed in kVA Transformer short circuit Vsc Transformer short circuit Vse J B 2a The short circuit voltage value of the grid transformer expressed as a percentage of the rated voltage Starting from that value you can calculate the transformer short circuit current Power of linear loads Power of linear loads A 00 kVA The overall power of non linear and non distorting loads if any supplied through the same grid transformer MV side value ROR aie J 5 00 kv The nominal value of the MEDIUM VOLTAGE side expressed in kV 5 23 USER MANUAL SANTERNO EASY HARMONICS GRUPPO CARRARO Short circuit current on MV side Short circuit current on MY side Y 3 000 kA The value of the expected short circuit current on MV side lt is expressed in kA Frequency Frequency Jl 50 Hz The operating frequency of the system 2 2 Distorting Loads Inverters Data Size of the inverter 505 5 The button for selecting the size of the inverter When you click the button a list appears showing all the sizes of Elettronica Santerno s inverters Selection
4. ARO I Vrs VRT VsT VSR VTR VTS Ny Fo A e ZN N f Ni ff Ni Fi X ri a y A A f E f E N INN UN Sl ie A ce xl de T OS ho e RR er ct P000954 B Figure 9 Line current voltage when using a 12 pulse configuration 18 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 6 2 Voltage Distortion The voltage distortion on a grid occurs when a non sinusoidal load is applied Figure 10 The current flowing from the voltage generator to the non sinusoidal load cause in the delivery point a voltage contribution proportional to the product of each current harmonic amplitude multiplied by the grid impedance calculated at the frequency of the corresponding current harmonic An ideal grid has a null output impedance Z 0 this means that in case of a short circuit in the delivery point the current flowing assumes a theoretically infinite value As this is not possible the grid impedance in the delivery point is not null The current absorbed from the grid by non disrtorting loads can be considered as the addition of several components each of them is characterized by frequency and amplitude that can be calculated with the relation in 6 1 Figure 10 Basic diagram in the delivery point a In no load conditions I n 0 the available voltage V n in the delivery point equals the no load voltage of the generator V n E b when the connected l
5. Figure 4 as a calculation model The harmonic content is calculated in respect to the value of L and Ly and to the resonant filter as well 11 23 USER MANUAL 5 SANTERNO EASY HARMONICS 4 2 Calculation Results Low voltage side LOW VOLTAGE Current distortion THDI Voltage distortion THDV 0 00 Total RMS Distorted Current A oor 0 00 Power Factor 0 00 This window shows the calculation results of the transformer low voltage side Current distortion Voltage distortion Total RMS distorted current absorbed from the grid and including all the current harmonics Grid side power factor the ratio between the active power and the apparent power Medium voltage side MEDIUM VOLTAGE Current distortion THDI 0 00 Voltage distortion THDV 0 00 Total RMS Distorted Current A 000 Power Factor 0 00 The calculation results of the transformer medium voltage side Current distortion Voltage distortion Total RMS distorted current absorbed from the grid and including all the current harmonics Grid side power factor the ratio between the active power and the apparent power 12 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 4 3 Calculated Plant Data RESULTS LOW VOLTAGE Calculated short circuit 15 750000 MIVA power on LY side 1 harmonic current 253 78 j A Rsce IEC 61000 3 12 98 44 MEDIUM VOLTAGE Calculated s
6. OJH 0 0 AGHL uomojsip abeqo _ 9 99Tb zr e 00019 931 eosy __ v 8z IGHL uomojsipqueung v Pe 9 yuana guouney ast JDVLIOA MOT VAN 29999991 a a a oe DVLIIOAMOT synsoy GHL xaa oNuzinvs Z SUNS Y onulainvs Z io ic ct 91 a os E va ooze E Al ooz E 16 0 E Weil oot 5000 INAd SNNIS Wel oo E ea 9 a yal coor f WI oor E 10119 JY asd Acuanba 4 apis Al UO Juano INI 1 1045 anjeA apis AW AJUDA 1931941 4103011 UBAP jo Jamod payeysul 6101 gt cog 9215 Jaanu 5peo JESUIT JO Jag 354 JIMA 311045 ISLJOJSuUEe JALUIOJSUE AY ayy 40 Jamod jeuuopy apis abejjoA moj UO abeyoa eumuony DO Dhl VED ONUZINYS Z daH all SILUOLJEH SEJ s Figure 2 Main window of the Easy Harmonics software 4 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 2 INPUT PARAMETERS The calculation results are processed by the Easy Harmonics software based on the parameters of the application to be checked 2 1 Grid Data The grid data varies from plant to plant It is known by the end user but not by the manufacturer of the equipment and it dramatically affects the calculation results If the input parameters are not perfectly known you can enter approximate values to get estimated results The values to be entered are
7. RVIEW rasca lees 3 Zo ANPUTPARAMETER Sia iii aid 5 A A un O In E 5 2 2 Distorting Loads Inverters Data ooocooccocccocnoncnoncnononnconncnncnnncnnncnnncnonnnncnoncnnnnnnnnnncnnncnnanoncnnns 6 Se DESIGN TOOLS isisaeescecesaieaeedorcusmeedsncnasaestorsuunvacsdaseoatwouaseecsensanunsdvessenven tone beisuieasetessaeadeameesscnouesvens 7 As RESULTS tiara 10 4 1 AT CO CONIL Oo 10 42 Calculation Res tritio 12 Ls Cace ridad 13 Ds MENU BAR usina ina 14 5 1 A e vides outa nous ae On apnea ventana eoonen rasa 14 5 2 BEELA MU ANE N EA E OAN I E AT ETA E 15 6 THEORETICAL NOTIONS sins arias 16 6 1 SAN MOE IO eo yA e EEE a 16 6 2 Voltage DISTOR Olt aiisecoonas wee A ees macecosentoane Secleueasseae he deteaueoopis E TE E E 19 6 3 LOWER OT ee 21 7 REFERENCE STANDARD Sonar aten ir 23 0 2 Figures Figure 1 Logo of the Easy Harmonics software ooocccccoccnccoccnnonnnnonononononcnnnnnonononnnnnnnnnnonnnonnnnnonnnnnonononnnnnnnnos 3 Figure 2 Main window of the Easy Harmonics SOFWAre ooccccoccnconcncncnnonccnonncnnononnnncnnoncnnoncnnoncnnnnnnnoncnnonannnns 4 Figure 3 Readout of the harmonic Current content occcocccnccnnncnnnnnnnconnnnnnnonnnnononcnnncnnnonnnnnnnncnnncnnnonnnncnnnninnnoss 9 Figure 4 Circuit diagram including a mains reactor and a resonant filter oooccoocconcnnncnnnnnnnncnnnonnns 10 Figure 5 Circuit diagram including a mains reactor Only coocccoccnocnnnnnncnnocnnncnonnnncnnncnnnnnncnnncn
8. armonic only so the current harmonics larger than the first one will be responsible only for the Joule effect losses in the mains conductors Knowing the harmonic contents of the current absorbed by an inverter allows arranging the corrective actions for reducing the harmonics The Easy Harmonics software is a tool for calculating the current distortion and the voltage distortion localized in the current delivery point in a grid when loads are controlled by inverters The possible corrective actions for reducing the harmonic currents are also considered PO00946 0 Figure 1 Logo of the Easy Harmonics software 3 23 EASY HARMONICS GRUPPO CARRARO o z Z A USER MANUAL Jagun IUO EH TS br EP OP EF TF DE LE SE EE TE br Le oe EE LE BT EL OT NJL LNOJ LNF FANI JINON RA ET TT 6 E E E E i AAA AAA NAAA A NA AAA AA A A NA A A A A A A AA A A A ANNA A EAN 0 96 apro cl oor 08 09 OF De 0 ool 00 00T a5eyuazad peo AGHL IGHL HND MOLA e 96 0 103384 Jamo Me ee eee oie ero y qualing pajuozsig SWH 8301 ZO O _ _ anjeA pajsab ns 1013893 JG 00 0 AGHL Yomojsip sbeqjo TN TE Lv 8e IGHL 4041035Ip queuing oca JOVLIOA HNITIN o a e 96 0 103384 J3M0g VAN 61269 STr m ie comics o99 y auno payuoxsIg SWY BIOL JDVLIOA HNI
9. e 16B2011B1 e EASY HARMONICS USER MANUAL Issued on 03 08 09 R 00 English e This manual is integrant and essential to the product Carefully read the instructions contained herein as they provide important hints for use and maintenance safety e The software described in this manual is a tool helping the design of inverters Elettronica Santerno is not responsible for any direct and or consequential damages due to the implementation of the Easy Harmonics e Elettronica Santerno reserves the right to make any technical changes to this manual and to the software without prior notice If printing errors or similar are detected corrections will be included in the new releases of this manual e Elettronica Santerno is responsible for the information contained in the original version of the Italian manual e The information contained herein is the property of Elettronica Santerno and cannot be reproduced Elettronica Santerno enforces its rights on the drawings and catalogues according to the law SANTERNO GRUPPO CARRARO Elettronica Santerno S p A Strada Statale Selice 47 40026 Imola BO Italy Tel 39 0542 489711 Fax 39 0542 489722 www elettronicasanterno com sales elettronicasanterno it USER MANUAL SANTERNO EASY HARMONICS GRUPPO CARRARO 0 TABLE OF CONTENTS 0 1 Chapters O TABLE OF CONTENTS scecceas cincevescseictsanpanctoneen cesupaveusniedeuenaprsncasoovevs A 2 0 1 AP e No o e 2 0 2 Se CU ne PO O 2 le OVE
10. hort circuit 415 69219 MVA F power on MY side 1 harmonic load 5 08 A current on MY side J Transformer ratio 00 00 The plant data based on the input data e Grid short circuit power both LOW VOLTAGE and MEDIUM VOLTAGE side e RMS value of the first harmonic current caused by the distorting load only both LOW VOLTAGE and MEDIUM VOLTAGE SIDE The current values of non distorting linear loads are not considered e Re the ratio between the grid short circuit power and the overall power of the distorting loads in compliance with IEC 61000 3 12 e Transformer ratio 13 23 USER MANUAL Z SANTERNO EASY HARMONICS GRUPPO CARRARO 5 MENU BAR The Easy Harmonics software includes two menus the File menu and the Help menu 5 1 File Menu The File menu includes 5 submenus one for each of the following functions Open Project Chris Save Projeck Chrl s Report Ctrl F CS Table Ctrl T Ctrl g e Open project opens a saved project e Save project saves a project e Report creates a report of a project as HTML e CSV Table creates a file with CSV extension The CSV file contains the data related to the current voltage spectrum harmonic content e Exit quits the Easy Harmonics application 14 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 5 2 Help Menu The Help menu includes 3 submenus one for each of the following functions Eas
11. increases when L decresaes The suggested value for Ly is the value for which when the current is 80 of the rated current the minimum current drops to zero in the central value in 1 2 and in 32 2 When the current flowing is 100 the waveform is continuous in the range between 2 6 and 57 6 Any inductance value Ly exceeding the minimum suggested value makes the waveform continuous for current flowing values lower than 80 of the rated current Use the cursor to change the value of Ly The distortion value is recalculated in real time 8 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL Load percentage Load Percentage as 100 00 00 O 20 40 560 80 100 The cursor allows changing the value of the load power in respect to its maximum value When the load current varies the current flowing varies as well thus affecting the calculated harmonic content Harmonic current content HARMONIC CURRENT CONTENT 100 Amplitude a ho hu E qn T 18 Ww a a a a a a a a H ao a rn l man l I l l I 11 l 1d l et l A l od l edt l re l e a I e i l e a l e l L i l I lIl l 1 I l 1d l 11 l e i l I l Il l 11 is 15 LY 19 21 23 25 2 7 28 31 53 29 23 294 e 43 4 Az m S1 Harmonic Murnber J n me LO Figure 3 Readout of the harmonic current content The current voltage spectrum is graphically represented in Figure 3 up to the 50th current ha
12. nncnnnonncnnnoss 10 Fig re 0 FOO UI WIIG Wai rn 15 Figure 7 Line current and voltage pattern escindida 16 Figure 8 Line current and voltage with increased conduction angle oocoocccoccoccnnconocnncnnncnnncnnncnncnnnoss 17 Figure 9 Line current voltage when using a 12 pulse configuration coooccocccoocnnnonnncnnnccnoncnonononcnnnnonononnns 18 Figure 10 Basic diagram in the delivery point s sn snnssnssnnsenseessessessesssrssnserssrssenserssrssrssersreserserssreseeseens 19 Figure 11 Diagram showing 3 delivery points PCC1 to PCC3 coooccoccccnccncccnnccnononononononnnccnoncnoncnnnnononcnononnns 20 2 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 1 OVERVIEW The power absorbed by a motor connected to an inverter depends both on the load torque and the motor speed Power is delivered through the conversion of the electric energy made from the inverter by transforming the AC voltage available from the mains with fixed frequency into DC voltage then into variable frequency AC voltage These transformations of energy require that the power be continuously delivered to the motor As a result apart from the performance of the system an equivalent power level is absorbed by the mains with constant voltage Therefore the current coming trom the mains and absorbed by an inverter operating in PWM mode is not sinusoidal and its harmonic contents are high The active power is transferred from the 1st h
13. oad is operating I n 0 the voltage in the delivery point is as follows V n E Z n jel n where Z n is the total line impedance The voltage distortion factor THDV in the delivery point is defined as follows THDV 100 calculated for n gt 1 LD A E Note that the voltage distortion depends on the value of Z n i e it depends on the geographical location of the delivery point Example Figure 11 shows a grid with different delivery points PCC1 or PCC2 based on the user whose THDV value is to be checked 19 23 USER MANUAL SANTERNO EASY HARMONICS GRUPPO CARRARO UVA 1000k VA k AO KV i o S y NY Ta 2000k VA 7 MA Ml PECI Die PAL Figure 11 Diagram showing 3 delivery points PCC1 to PCC3 The main power delivery is 150kV high voltage The first common delivery point PCC1 is downstream of the 20MVA transformer T1 on the 20kV MEDIUM VOLTAGE grid The other two delivery points are called PCC2 and PCC3 The distorted current absorbed from the user connected to PCC3 will cause a voltage distortion in PCC3 and a voltage distortion in PCC1 The voltage distortion in PCC1 could be large and cause troubles to the user connected to PCC2 For that reason you should calculate the contribution to the voltage distortion in PCC1 due to the distorted current absorbed from the user connected to PCC2 separately from the contribution to the voltage distortion due to the cu
14. of the inverter model SINUS PENTA 0005 The button for selecting the inverter model When you click the button the list of the inverter codes corresponding to the size of the inverter you have just selected appears based on the standard application table The inverter power is given in the field below Total installed power of motor driven inverters Total installed power of i gt motor driven inverters 4 0 KW After selecting the size and model of the connected inverters the total installed power is displayed 6 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 3 DESIGN TOOLS The Easy Harmonics provides a parameter set for the design of your plant Pulse 6 Y 12 The switch linked to this function allows changing the configuration of the connection of the inverter to the grid e 6 indicates that the inverter is supplied from the 3 phase mains with a single winding transformer e 12 indicates that the inverter is supplied from the 3 phase mains with a dual secondary transformer with a vector group Dyn11 DdO0 The calculation of the total current distortion THDI is based on the current flowing in the transformer current where the vector sum of the currents flowing in the two secondaries is done A double fed inverter is required AC reactor AC Reactor si ao 20 The button linked to this function allows changing the value of the grid reactor The default value is 3 corre
15. rmonic The harmonic amplitude is given as a percentage of the amplitude of the fundamental harmonic component When changing the input values the harmonic spectrum is recalculated in real time 9 23 GRUPPO CARRARO USER MANUAL Z SANTERNO EASY HARMONICS 4 RESULTS 4 1 Circuit Configuration J view circuit The View Circuit button allows displaying the overall circuit diagram Figure 4 including the position of the components used to reduce the harmonic contents If a resonant filter is installed calculation is based on the grid current and considers the contribution of the resonant filter Figure 4 If a mains reactor is installed calculation is made without considering the contribution of the resonant filter Figure 5 other linear load M V LV L ac e T ZS lA 0 E eae 2 oe eee resonant filter a E T a P000950 B Figure 4 Circuit diagram including a mains reactor and a resonant filter other linear La load dl iene aan ite enemies iene Motor MV LV Lac A P000951 B Figure 5 Circuit diagram including a mains reactor only 10 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL AC reactor This button allows choosing the circuit configuration in Figure 5 as a calculation model The harmonic content is calculated in respect to the value of Lac and Ly Resonant filter This button allows choosing the circuit configuration in
16. rrent distortion absorbed by the user connected to PCC3 The total distortion in PCC1 is the sum of the two contributions When calculating the voltage distortion you must know the characteristic data of the grid power of the transformers short circuit voltage voltage level etc 20 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 6 3 Power Factor The input power factor considered trom the grid side of a system composed of a motor and an inverter is different when the motor is supplied from the grid The current absorbed from the grid can have a harmonic content more or less large depending on the harmonic suppressing measures being used which increases the RMS value of that current and contributes alterating the measure of the power factor The measure systems generally used for the cos are obtained in order to measure the offset angle between the grid voltage and the current flowing However because the current is strongly distorted due to the harmonics the measure readout is often distorted as well and the angle measurement is incorrect As a result the readout of the cos is much lower than the actual cose It can happen that the power factor does not match with the cos as a matter of fact the power factor and the cosp match only when both voltage and current are true sinusoids The Total power factor is the ratio between the active power and the apparent power the coso is the cosine
17. shes the harmonic content of this waveform as follows f t gt 2A n cos nat 2 jB n sin nat n 0 n 0 6 1 A n and B n coefficients are calculated by means of the following equation WN A n jB n F n f e dt 0 6 2 If equation 6 2 is applied to the waveform in Figure 7 it will give the following result A n 0 L sin no7 B n sin sin sin u La nm 3 y 6 3 16 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL where l e duration of the current pulse E EEE current amplitude In order to reduce the harmonic values it is necessary to increase the conduction angle the solution offered T by Elettronica Santerno allows reaching a maximum value of this conduction time equalling om In that case the current waveform changes and becomes as in Figure 8 lt is composed of a single pulse 2 To having an lo amplitude and its duration increases up to 3 P000953 B Figure 8 Line current and voltage with increased conduction angle In that case FOURIER coefficients are the following A n 0 3N TT Lo sin n Ty sin va sin 2 2 B n nm Using a resonant filter for the 5th harmonic can further decrease the harmonic contents When a 12 pulse configuration is used Figure 9 the only harmonics to be found are for instance n 12k 1 where k 1 2 m 17 23 USER MANUAL Z SANTERNO EASY HARMONICS GRUPPO CARR
18. sponding to the voltage drop occurring when the rated inverter current flows in the reactor If you change the default value the current distortion and the voltage distortion in the delivery point is recalculated in real time Therefore you can see how the grid reactor value affects the harmonic currents The maximum programmable value is 20 N of filtered harmonics NS of Filtered Harmonic A 5 If a resonant filter is installed you can select the harmonic current component to be filtered The software automatically calculates the new harmonic contents and the value of the current distortion and the voltage distortion The modification of the harmonic order is independent of the ratings of the AC reactor Efficiency Efficiency d 0 91 The ratio between the mechanical power of the motors and the electrical power absorbed by the mains The default value is 0 91 it can be changed with the arrows 7 23 USER MANUAL Z SANTERNO GRUPPO CARRARO DC reactor DC Reactor Suggested Value A MUS 60632 mH 0 00 5 00 10 00 EASY HARMONICS The numeric value is the min value of the inductance to be installed on the DC side of the inverter so that the measured distortion value is the same as the calculated value If the inductive value of Ly is lower than the displayed value the DC side current takes a waveform composed of two pulses in 1 3 and 2 1 3 whose width increases when increasing the value of Lye and whose amplitude
19. tal power factor is worth 0 8944 the opposite of 1 118 On the other hand if you have an instrument measuring the apparent power it is not correct to get the value of the cos as the ratio between the active power and the apparent power because the latter is higher due to the harmonic contribution THDI of the current which is not sinusoidal 22 23 GRUPPO CARRARO EASY HARMONICS Z SANTERNO USER MANUAL 7 REFERENCE STANDARDS The Easy Harmonics software has been developed using the calculation method and formulas prescribed by EN 61000 3 12 The following relations are used for calculation 40 2 Total current harmonic distortion THD gt 2 n 2 LY e Common connection point PCC the point in the grid the closest to the disturbing user where other disturbed users can be connected to e Short circuit power Ssc the value of the three phase short circuit power calculated considering the rated phase voltage U and impedance Z of the system up to the PCC e Rated apparent power of the equipment Seau value computed based on the rated line current leau of the equipment and on phase voltage U S equ gt V3 U Legu e Active power Sa power from the first current harmonic only S V3 U H e Short circuit ratio Re ratio between the short circuit power and the apparent power of the equipment S SC sce S equ R e Fundamental current of reference l the first harmonic current defined as
20. y Harmonics File Ea Italian Help Se English Help e Italian Help views the help manual of the Easy Harmonics in Italian e English Help views the help manual of the Easy Harmonics in English e About displays program information and version number About Easy Harmonics NTE GRUPPO CARRARO ha Easy Harmonics version 7 0 SOG 2008 ELETTRONICA SANTERNO 5 p 4 Strada Statale Selice 47 40026 Imola Bo Italy Tel 39 0542 489711 AUTHORS Fax 39 0542 489722 Computations development by Domenico Di Cesare Software development by Luca Ferraresi Figure 6 About window 15 23 USER MANUAL O SANTERNO EASY HARMONICS GRUPPO CARRARO 6 THEORETICAL NOTIONS 6 1 System Model The input stage of an inverter is usually formed by a three phase diode bridge rectifier whose load is a capacitor bank and the inverting stage which is the same as a real R resistance Because of this the current line has not a sinusoidal shape but for each half cycle it is formed by two pulses that are symmetrically positioned at angle 1 3 and 27 3 whose width is established by R and C values Figure 7 VRS VRT VsT VSR VTR Vis SS Sue So tay a a YAA V V V Y A Y A Y A A j Z N XK Z h A EOT X JL X X X X X gt Nese a de laa ee ee he Se eee aie he Seo ad a a er la RE eae P000952 B Figure 7 Line current and voltage pattern The FOURIER relation establi
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