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DRM019, 3-Phase AC Induction Motor Drive with Dead Time

1. DRM019 Rev 0 Designer Reference Manual MOTOROLA System Setup 51 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Pse o pifo ol Palo o Jilo ol Jz 0 0 ze g t amp amp amp SW POWER WIM WM WM WM WM WME JP7 J JP5 Ji o_o Motorola Js o o JP1 Swi o RESET l 3 HC908MR32 MC BOARD 3 TO EMULATOR i JP 39 B 1 HBSGGEEEBSB8R393088 40 2 2 i o C22 sw4 TACHO i FW REV 4 SPEED O I ref V STOP g START Figure 5 2 MC68HC908MR32 Jumper Reference Table 5 1 MC68HC908MR32EVM Jumper Settings Jumper Group Comment Connections JP1 Tachometer input selected No connection JP2 Encoder input selected 1 2 JP3 Back EMF signals selected No connection Power factor correction zero cross JP4 No connection signal selected JP5 Power factor correction PWM signal selected No connection JP7 Power Supply connected to jack J3 1 2 5 5 Required Software Tools The application requires the following software development tools Designer Reference Manual DRM019 Rev 0 52 System Setup MOTOROLA For More Information On This Prod
2. Software Design Data Flow 4 3 1 Speed Command amp Status Control In the Manual Operating Mode the required speed is set by speed potentiometer and switches start stop forward reverse In the PC Master Software Remote Operating Mode the required speed is set by PC In the process the input parameters are evaluated and the speed command is calculated accordingly Also the DC Bus voltage is measured The application fault status is analyzed and the state of the drive is set The status LED s are controlled according to the system state 4 3 2 Acceleration Deceleration Ramp 4 3 3 V Hz Ramp The process calculates the new speed command based on the required speed according to the acceleration deceleration ramp This process provides voltage calculation according to V Hz ramp The input of this process is the generated inverter frequency omega_req_RMP_mech The outputs of this process are the output sine wave parameters required by PWM generation process the table increment phase_increment that corresponds to the frequency omega_req_RMP_mech and is used to roll through the wave table in order to generate the output inverter frequency and the corresponding amplitude of the generated inverter voltage u_ramp 4 3 4 Process PWM Generation DRM019 Rev 0 This process generates a system of three phase sinewaves shifted 120 each other The function mcgen3PhWaveSine is used for the sine wave calculation The mcgen3PhWa
3. Freescale Semiconductor Inc List of Figures Designer Reference Manual DRM019 Rev 0 10 MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC DRM019 Rev 0 Table 5 1 List of Tables Title Page PWM values loaded into registers PVAL1 6 22 PWM PE i dad eae a kp hh ksh kh he eS ee he 22 Sensing of the Current Polarity and Magnitude for Ph 1 25 Electrical Characteristics of Control Board 30 Electrical Characteristics of Power Stage 33 Electrical Characteristics of Optoisolation Board 34 Motor Brake Specifications 000c eee 35 State Machine Flag Registers dtStateFlagsAB 46 State Machine Flag Registers dtStateFlagsC 46 dtCorrect_s Structure Elements 000005 47 MC68HC908MR32EVM Jumper Settings 52 Motor Application States 0 0 0 eee 56 Dead Time Distortion Correction 000005 57 Designer Reference Manual MOTOROLA 11 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc List of Tables Designer Reference Manual DRM019 Rev 0 12 MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive
4. Software Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design Algorithm of Dead Time Distortion Correction DC Bus Over voltage In case of DC Bus over voltage the external hardware provides a rising edge on the DC Bus over voltage fault input of the microcontroller This signal disables all motor montrol PWM outputs PWM1 PWM6 and sets the application fault status DC Bus Under voltage The sensed DC Bus voltage is compared with the limit within the software In case of DC Bus under voltage all motor control PWM outputs PWM1 PWM6 are disabled and the application fault status is set If any of the faults occurs the application status is changed into the Fault Status 4 3 7 Dead Time Distortion Correction The process defines the value registers to be used for PWM generation according to the type of dead time distortion correction and the state of the immediate phase current polarity e f no dead time correction is required the PVAL1 3 5 are used the complementary PVAL values are calculated by on chip PWM peripheral automatically e f partial dead time correction is required the PVAL value is selected by on chip PWM peripheral automatically according to the phase current polarity sensing e If full dead time correction is required the process selects the desired PVAL registers according to the dead time distortion correction state machine
5. 2 geadtime PWM to top transistor fect ceo aS PWM to bottom transistor ty Ton 2 deadtime Actual load voltage for i U 2 Ton 2xdeadtime Actual load voltage for i Figure 2 3 Dead Time Distortion DRM019 Rev 0 Designer Reference Manual MOTOROLA System Description 19 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Description To achieve distortion correction one of two different correction factors must be added to the desired PWM value depending on whether the top or bottom transistor is controlling the output voltage during the dead time When the voltage pulse is shortened due to dead time the control PWM signal is extended by dead time so the actual voltage pulse matches the desired voltage Vice versa when the voltage pulse is lenghtened due to dead time the control PWM signal is shortened by dead time so again the actual voltage pulse matches the desired voltage Therefore the actual signal equals the desired one and the generated phase current is sinusoidal The dead time distortion correction utilizes phase current sensing The on chip PWM module of MC68HC908MRxx microcontrollers contains the block that enables them to evaluate the polarity and the size of the phase current without the need of an expensive current sensor It is based on the sampling and evaluation of the phase voltage level during the dead t
6. If an isolation transformer is not used power stage grounds and oscilloscope grounds are at different potentials unless the oscilloscope is floating Note that probe grounds and therefore the case of a floated oscilloscope are subjected to dangerous voltages The user should be aware that e Before moving scope probes making connections etc it is generally advisable to power down the high voltage supply e To avoid inadvertent touching live parts use plastic covers e When high voltage is applied using only one hand for operating the test setup minimizes the possibility of electrical shock e Operation in lab setups that have grounded tables and or chairs should be avoided e Wearing safety glasses avoiding ties and jewelry using shields and operation by a personnel trained in high voltage lab techniques is also advisable e Power transistors the PFC coil and the motor can reach temperatures hot enough to cause burns e When powering down due to storage in the bus capacitors dangerous voltages are present until the power on LED is off 5 4 Jumper Settings of Controller Board The MC68HC908MR32z2 control board jumper settings shown in Figure 5 2 and Table 5 1 are required to execute the 3 phase AC motor control application with dead time distortion correction For a detailed description of the jumper settings refer to the MC68HC908MR32 Control Board User s Manual Motorola document order number MEMCMR32CBUM D
7. In the following section the dead time distortion correction algorithm is described in detail 4 4 Algorithm of Dead Time Distortion Correction The algorithm dtCorrectFull calculates the IPOL bits defining the PVAL registers to be used for MC68BHC908MR32 PWM generation for full dead time correction The IPOL bits are determined according to the phase DRM019 Rev 0 Designer Reference Manual MOTOROLA Software Design 43 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design current polarity detection bits DT1 6 actual sine wave pointer and the actual state of the algorithm state machine The algorithm state machine samples the actual state of the phase current and selects appropriate PVAL registers to be used for PWM generation The state machine implemented in the dtCorrectFull algorithm is illustrated in Figure 4 4 When the algorithm is enabled the state machine is entered from initial state 0 It is waiting till the high magnitude of positive current is detected State 1 confirmed by State 2 then the algorithm enters the state machine State 3 The state machine is performed in circle 3 4 5 6 3 As soon as the low magnitude of negative current is detected the IPOL is changed to 1 requesting the even numbered PWM registers to be used for PWM generation the actual value of the wave pointer is recorded 8c and State 4 is entered State 4 is preserved for 80 el
8. a ra f T 40 PIN RIBBON OVERCURRENT peas BACK EMF CONNECTOR OVERVOLTAGE SENSE INPUTS INPUTS INPUTS PWM 6 MISC POWER AND OUTPUTS CONTROL I O Figure 3 2 MC68HC908MR32 Control Board The electrical characteristics in Table 3 1 apply to operation at 25 C Table 3 1 Electrical Characteristics of Control Board Characteristics Symbol Min Typ Max Units DC power supply voltage Vdc 10 8 12 16 5 V Quiescent current lcc 80 mA Min logic 1 input voltage y MR32 H an Max logic 0 input voltage y _ MR32 IL 0 8 V Propagation delay Hall sensor encoder input taty T 7200 ns Analog input range Vin 0 5 0 V RS 232 connection speed 9600 Baud PWM sink current IpK 20 mA d n operated and powered separately from other Embedded Motion Control tool set prod ucts Designer Reference Manual DRM019 Rev 0 30 Hardware Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Hardware Design 3 Phase AC BLDC High Voltage Power Stage 3 4 3 Phase AC BLDC High Voltage Power Stage Motorola s embedded motion control series high voltage HV AC power stage is a 180 watt one fourth horsepower 3 phase power stage that will operate off of DC input voltages from 140 to 230 volts and AC line voltages from 100 to 240 volts In combination with one of the embedded motion control series c
9. between the turning off of one transistor in the inverter half bridge and turning on of the complementary transistor The dead time causes distortion to the generated voltage and thus a non sinusoidal phase current Designer Reference Manual DRM019 Rev 0 18 System Description MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Description Dead Time Distortion Correction In order to achieve a sinusoidal phase current and thus limit the harmonic losses noise and torque ripple the dead time distortion correction needs to be implemented The on chip Pulse Width Modulation PWM module of the MC68HC908MRxx family of Motorola microcontrollers contains the patented hardware block that simplifies the task The dead time correction is based on the evaluation of the phase current polarity of the respective phase and proper counter modulation of the dead time distortion The basic situation is shown in Figure 2 3 The desired load voltage is affected by the dead time During dead time load inductance defines the voltage needed to keep inductive current flowing through diodes So full positive or full negative voltage is applied to the phase according to the phase current polarity For positive current i the actual voltage pulses are shortened by dead time for negative phase current the voltage pulses are lengthened by dead time Desired load voltage Ton U
10. depending on whether the top or bottom transistor is controlling the output voltage during the dead time The software is responsible for calculating both compensated PWM values and placing them in an odd even PWM register pair Then the s w needs to determine which PWM value is to be used according to the following scheme e lf the current sensed at the motor for that PWM pair is positive and of high magnitude or negative and of small magnitude in a trend approaching zero crossing the odd PWM value is used for the PWM pair e Likewise if the current sensed at the motor for that PWM pair is negative or positive and of small magnitude in a trend approaching zero crossing the even PWM value is used The MR32 contains a hardware circuitry that enables it to sense the current polarity together with the magnitude The current polarity and magnitude is sensed using the DT DT6 of FTACK register in 908MR32 Designer Reference Manual DRM019 Rev 0 24 System Description MOTOROLA For More Information On This Product Go to www freescale com DRM019 Rev 0 Freescale Semiconductor Inc System Description Dead Time Distortion Correction microcontroller For Phase 1 the bits DT1 and DT2 are used as shown in Table 2 3 Table 2 3 Sensing of the Current Polarity and Magnitude for Ph 1 DT1 DT2 Current Condition of Phase 1 0 0 high magnitude I 1 1 high magnitude l 0 1 low magnitude either pola
11. inputs are accepted from START STOP FWD REV switches and a SPEED potentiometer located on the control board Alternately motor commands can be entered via a PC and transmitted over a serial cable to DB 9 connector Output connections and power stage feedback signals are grouped together on 40 pin ribbon cable connector Motor feedback signals can be connected to Hall sensor encoder connector Power is supplied through the 40 pin ribbon cable from the optoisolation board or low voltage power stage The control board is designed to run in two configurations It can be connected to an M68EM08MR32 emulator via an M68CBLO8A impedance matched ribbon cable or it can operate using the daughter board The M68EMO8MR32 emulator board may be used in either an MMDS05 08 or MMEVS05 08 emulation system Figure 3 2 shows a block diagram of the board s circuitry DRM019 Rev 0 Designer Reference Manual MOTOROLA Hardware Design 29 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Hardware Design ae FORWARD REVERSE SPEED K OFTOISO SWITCH POT TACHOMETER RS 232 I F TERMINAL START STOP INPUT VF SWITCH MALL EFFECT INPUTS 3 EMULATOR S e a PROCESSOR Z o SWITCHES REGULATED 200000 do POWER POWER SUPPLY PWM LEDs 6 12 Vde OPTO POWER DRIVER I O CONNECTOR
12. phase A is updated by the table increment e Based on the wave pointer the PWM values for all three phases are calculated e PWM values are rescaled according to the PWM modulo PWM frequency and loaded into PVAL1 3 5 registers Registers PVAL2 4 6 are loaded automatically because of complementary PWM mode selected during the PWM module initialisation e Incase of dead time distortion correction the corrected values PVAL1 6 are calculated and used for PWM generation according to the detected phase current polarity The process is accessed regularly in the rate given by the set PWM frequency and the selected PWM interrupt prescaler 4 3 5 PC Master Software Control 4 3 6 Fault Control Designer Reference Manual The process provides SCI communication with PC using PC master software service routines These routines are fully independent on the motor control tasks They enable for example to set the desired speed the PWM frequency and the type of dead time distortion correction This process is responsible for fault handling The software accommodates three fault events DC Bus over current DC Bus over voltage and DC Bus under voltage DC Bus Over current In case of DC Bus over current the external hardware provides a rising edge on the DC Bus over current fault input of the microcontroller This signal disables all motor control PWM outputs PWM1 PWM6 and sets the application fault status DRM019 Rev 0 42
13. the on chip dead time correction block is set in the automated mode current sense correction bits ISENS1 ISENSO of PWM Control Register 0 PCTL1 are set to 10 The disadvantage of the partial correction is that some dead time distortion still exist the current is flattened out at the zero crossings Full dead time distortion correction implemented in dtCorrectFull algorithm improves the partial dead time correction by sensing not only the polarity but also the magnitude of the actual phase current In the full dead time correction method the threshold where the correction values should be toggled is not in the zero level but slightly advanced The threshold is illustrated in Figure 2 5 Toggling of the correction offset needs to occur before the current has a chance to Designer Reference Manual MOTOROLA System Description 23 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Description flatten out at a current zero crossing So the current sense scheme must sense that the current waveform is approaching the zero crossing Current with Correction Disabled High Positive Falling threshold Magnitude Low Magnitude High Negative Rising threshold Magnitude Figure 2 5 Proposed Current Threshold for Correction Toggling To achieve the full distortion correction again one of two different correction factors must be added to the desired PWM value
14. with DTC Section 1 Introduction 1 1 Contents 1 2 Application Functionality cise see dase eensneeddds 13 1 3 Benefits of the SGUNON cucece wae is dces er eeeeee ee ew on 13 1 2 Application Functionality This Reference Design describes the design of a 3 phase AC induction motor drive with dead time distortion correction It is based on Motorola s MC68HC908MR32 microcontroller which is dedicated for motor control applications The system is designed as a motor drive system for medium power three phase AC induction motors and is targeted for applications in both industrial and appliance fields e g washing machines compressors air conditioning units pumps or simple industrial drives The reference design incorporates both hardware and software parts of the system including hardware schematics with a bill of material and a software listing 1 3 Benefits of the Solution The design of very low cost variable speed 3 phase motor AC control drives has become a prime focus point for the appliance designers and semiconductor suppliers Replacing variable speed universal motors by maintenance free low noise asynchronous induction motors is a trend that supposes total system costs being equivalent Six transistor inverter is the most used topology for AC motor drives The dead time must be inserted between the turning off of one transistor in the inverter half bridge and turning on of the complementary transistor DRM0
15. 19 Rev 0 Designer Reference Manual MOTOROLA Introduction 13 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Introduction Designer Reference Manual The dead time causes distortion to the generated voltage and thus a non sinusoidal phase current This distortion causes distortion of the motor performance It is especially apparent in low speeds when the dead time is comparable with the PWM pulse width Also the longer the dead time the higher the influence it has over the motor performance Dead time distortion can be corrected by properly modulating the power stage control signals The advantages of dead time distortion correction are e Smoother running motors e Less torque ripple e Quieter motors e More efficient operation less harmonic losses DRM019 Rev 0 14 Introduction MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC Section 2 System Description 2 1 Contents 2 2 System LONG 6 4k pti od dee eade we iok dee as ew eeeek ses 15 2 3 Dead Time Distortion Correction 2 18 2 2 System Concept The application is designed to drive a 3 phase AC motor in an open speed loop mode with dead time distortion correction see Figure 2 1 The desired speed is set up in the user interface The desired frequency and a
16. 32CBUM D U2 3 ph AC BLDC High Voltage Power Stage supplied in kit with Optoisolation Board as ECOPTHIVACBLDC described in Motorola Embedded Motion Control 3 Phase AC BLDC High Voltage Power Stage User s Manual MEMC3PBLDCPSUM D U3 Optoisolation Board supplied with 3 ph AC BLDC High Voltage Power Stage as ECOPTHIVACBLDC or supplied alone as ECOPT optoisolation board described in Motorola Embedded Motion Optoisolation Board User s Manual MEMCOBUM D MB1 Motor Brake AM40V SG40N supplied as ECMTRHIVAC Detailed descriptions of individual boards can be found in comprehensive User s Manuals belonging to each board The manuals are available on the Motorola web The User s Manual incorporates the schematic of the board description of individual function blocks and a bill of materials An individual board can be ordered from Motorola as a standard product Designer Reference Manual DRM019 Rev 0 36 Hardware Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC Section 4 Software Design 4 1 Contents Aa I ai beet ead eh be bre nae kite 37 me Paa FON 654 ee oy RR ROE EEE ASARTAR ee er 37 4 4 Algorithm of Dead Time Distortion Correction 43 4 2 Introduction This section describes the design of the software blocks of the drive The software will be de
17. Freescale Semiconductor Inc eto oye MOTOROTA digital dna intelligence everywhere 3 Phase AC Induction Motor Drive with Dead Time Distortion Correction Using the MC68HC908MR32 Designer Reference Manual M68HC08 Microcontrollers DRM019 D Rev 0 03 2003 MOTOROLA COM SEMICONDUCTORS For More Information On This Product o to www freescale com Freescale Semiconductor Inc For More Information On This Product Go to www freescale com Freescale Semiconductor Inc 3 Phase AC Induction Motor Drive with Dead Time Distortion Correction Reference Design Designer Reference Manual Rev 0 by Radim Visinka Ph D Motorola Czech Systems Laboratories Roznov pod Radhostem Czech Republic DRM019 Rev 0 Designer Reference Manual MOTOROLA 3 For More Information On This Product o to www freescale com Freescale Semiconductor Inc Revision history To provide the most up to date information the revision of our documents on the World Wide Web will be the most current Your printed copy may be an earlier revision To verify you have the latest information available refer to http www motorola com semiconductors The following revision history table summarizes changes contained in this document For your convenience the page number designators have been linked to the appropriate location Revision history Revision mee Page Date Lavel Description Number s Janua
18. GE http motorola com semiconductors Information in this document is provided solely to enable system and software implementers to use Motorola products There are no express or implied copyright licenses granted hereunder to design or fabricate any integrated circuits or integrated circuits based on the information in this document Motorola reserves the right to make changes without further notice to any products herein Motorola makes no warranty representation or guarantee regarding the suitability of its products for any particular purpose nor does Motorola assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability including without limitation consequential or incidental damages Typical parameters which may be provided in Motorola data sheets and or specifications can and do vary in different applications and actual performance may vary over time All operating parameters including Typicals must be validated for each customer application by customer s technical experts Motorola does not convey any license under its patent rights nor the rights of others Motorola products are not designed intended or authorized for use as components in systems intended for surgical implant into the body or other applications intended to support or sustain life or for any other application in which the failure of the Motorola product could create a situation where p
19. Inc Designer Reference Manual 3 ph ACIM Drive with DTC DRM019 Rev 0 Appendix A References Motorola Inc 2001 68BHC908MR32 User s Manual MC68HC908MR32 D Motorola Inc 2000 Motorola Embedded Motion Control MC68HC908MR32 Control Board User s Manual MEMCMR32CBUM D Motorola Inc 2000 Motorola Embedded Motion Control 3 Phase AC BLDC High Voltage Power Stage User s Manual MEMC3PBLDCPSUM D Motorola Inc 2000 Motorola Embedded Motion Optoisolation Board User s Manual MEMCOBUM D Motorola Inc 1997 Making Low Distortion Motor Waveforms with the MC68HC708MP16 AN1728 Designer Reference Manual MOTOROLA References 61 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc References Designer Reference Manual DRM019 Rev 0 62 References MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual DRM019 DRM019 Rev 0 Appendix B Glossary AC Alternating Current ACIM AC Induction Motor ADC Analogue to Digital Converter BLDC brushless DC motor DC Direct Current DT see Dead Time DT DTC Dead Time Correction see Dead Time DT Dead Time DT short time that must be inserted between the turning off of one transistor in the inverter half bridge and turning on of the complementary transist
20. MR322 controller board Designer Reference Manual MOTOROLA System Description 17 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Description The PWM frequency can be changed at any time during the motor operation to one of the following values 4kHz 8kHz 16kHz 32kHz The drive incorporates fault protection so in the case of DC Bus over current DC Bus over voltage or DC Bus under voltage faults internal fault logic is asserted and the application enters a fault state This state can be exited only if the fault disappears and it is acknowledged by toggling the START STOP switch through the STOP state The application states are displayed by green LED on 908MR32 control board The application can operate in two modes 1 Manual Operating Mode The drive is controlled by the START STOP switch The direction of the motor rotation is set by the FWD REV switch The motor speed is set by the SPEED potentiometer 2 PC Master Software Remote Operating Mode The drive is controlled remotely from a PC through the serial communications interface SCI communication channel of the MCU device via an RS 232 physical interface The drive is enabled by the START STOP switch which can be used to safely stop the application at any time 2 3 Dead Time Distortion Correction Six transistor inverter is the most used topology for AC motor drives The dead time must be inserted
21. More Information On This Product Go to www freescale com DRM019 Rev 0 Freescale Semiconductor Inc System Description System Concept Phase Voltage A Base Point 100 Boost is Voltage xo 4 Boost Base Frequency rpm Frequency Frequency Figure 2 2 Volt per Hertz Ramp The Volt per Hertz ramp is defined by following parameters e Base Point defined by Base Frequency usually 50Hz or 60Hz e Boost Defined by Boost Voltage and Boost Frequency The ramp profile is set to the specific motor and can be easily changed to accommodate different ones The dead time distortion correction algorithms provide a correction of the PWM values with respect to the actual polarity of the phase currents The current polarity is evaluated by sensing the phase voltage during the dead time and is carried out by the on chip circuitry of the 9O8MR32 microcontroller Two types of dead time distortion correction algorithms are implemented partial and full correction The partial correction algorithm detects just the current polarity and the correction is done almost entirely by the on chip PWM hardware On the other hand the full correction algorithm also detects the magnitude of the phase currents low high and implements advanced s w which improves the correction results The user has the choice of selecting either of the correction algorithms The type of dead time distortion correction is indicated by a yellow LED on 908
22. NE si od ete eee sivcsideedeecende semen 15 Dead Time Distortion Correction 2 18 Section 3 Hardware Design CONS poder E NE ele ee eh ents E EEE ee en es 27 System Configuration icaseehadedksd Kobe eeeb ew abe 27 MC68HC908MR32 Control Board 22000 29 3 Phase AC BLDC High Voltage Power Stage 31 CSO GOSH Board ihicse ke eee ceers eee nen tenn de 33 Motor Brake Specifications nanana aaaea 35 Hardware Documentation n a aaua 36 Section 4 Software Design E E AE EEE EEREN EEEE A EE AS A EA E EEE E AE 37 Saele ia iala E de Rea E E EESE E E E ES 37 DAA FOW redara Erre Er a Pa ey ee eA 37 Designer Reference Manual MOTOROLA 7 For More Information On This Product Go to www freescale com Designer Reference Manual Freescale Semiconductor Inc Table of Contents 4 4 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 Algorithm of Dead Time Distortion Correction 43 Section 5 System Setup COMENS spanie aree DA AS EEEO 49 Hardware Setup isso hate en ieee das ee adadeaw aden 49 PMG sds cceerbacwasaphwiddsctaeocame EE AE DEA 50 Jumper Settings of Controller Board 51 Required Software Tools c ceccide cae scaaawadeaean 52 Building the Application 4 eewee cade bo hoa ee cede ada 53 Executing the Application 1 2cissei ddd dwnciaaacdeaeanca 53 Controlling the Application with PC Master Software 57 Appendix A Refere
23. Pulse Width Modulation reset To force a device to the known condition SCI See serial communications interface module SCl serial communications interface module SCI A module that supports asynchronous communication serial peripheral interface module SPI A module that supports synchronous communication software Instructions and data that control the operation of a microcontroller software interrupt SWI An instruction that causes an interrupt and its associated vector fetch SPI See serial peripheral interface module SPI SR switched reluctance motor timer A module used to relate events in a system to a point in time Designer Reference Manual DRM019 Rev 0 64 Glossary MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc For More Information On This Product Go to www freescale com Freescale Semiconductor Inc HOW TO REACH US USA EUROPE LOCATIONS NOT LISTED Motorola Literature Distribution P O Box 5405 Denver Colorado 80217 1 303 675 2140 or 1 800 441 2447 JAPAN Motorola Japan Ltd SPS Technical Information Center 3 20 1 Minami Azabu Minato ku Tokyo 106 8573 Japan 81 3 3440 3569 ASIA PACIFIC Motorola Semiconductors H K Ltd Silicon Harbour Centre 2 Dai King Street Tai Po Industrial Estate Tai Po N T Hong Kong 852 26668334 TECHNICAL INFORMATION CENTER 1 800 521 6274 HOME PA
24. ROL THE OUTPUT IPOL 1 EVEN NUMBERED PWM REGISTERS CONTROL THE OUTPUT Figure 4 4 Dead Time Correction State Machine Such a state machine is independently implemented for each phase A B C The algorithm contains 2 flag variables determining actual state of the state machine for individual phases Flag variable dtStateFlagsAB determines state of the state machine for phases A amp B dtStateFlagsC determines state of the state machine for phase C The meaning of individual bits of dtStateFlagsAB is listed in Table 4 1 The meaning of individual bits of dtStateFlagsC is listed in Table 4 2 DRM019 Rev 0 Designer Reference Manual MOTOROLA Software Design 45 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design NOTE Designer Reference Manual Table 4 1 State Machine Flag Registers dtStateFlagsAB State phase bits 7 5 3 a 5 5 bito lock 0 0 1 1 1 l biti 0 1 phase A ip 0 7 0 7 bita 0 0 1 1 bit4 lock 0 0 1 7 j 7 bit5 0 1 prase B fiig 0 i 0 i bit7 0 0 1 1 Table 4 2 State Machine Flag Registers diStateFlagsC State phase bits 7 5 3 a 5 5 bito lock 0 0 1 1 1 T bit1 phaset Fie 0 1 0 1 bit3 0 0 1 1 bit4 x X x X x x reserved bit5 xX X xX X x x bit6 x X x X x x bit7 xX X x X x x Detailed explanation of the de
25. ad time distortion correction can be found in a comprehensive application note of Motorola AN1728 Making Low Distortion Motor Waveforms with the MC68HC708MP16 by David Wilson Note that MC68HC708MP 16 is the predecessor of MC68HC908MRxx family and contains identical on chip PWM block Algorithm Data Structure Algorithm data structure is defined in dtCorrect h header file See Table 4 3 typedef struct UByte dtBits UByte ipolBits type uBits dtStateFlagsAB type uBits dtStateFlagsC DRM019 Rev 0 46 Software Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design Algorithm of Dead Time Distortion Correction SByte pointA SByte pointB SByte pointC SByte pointerA dtCorrect s Table 4 3 dtCorrect_s Structure Elements Variable Explanation INPUT actual status of the dead time bits DT1 6 dtBits format x x IDT6IDT5 IDT4IDT3IDT2IDT11 fits to FTACK of MR32 OUTPUT ipolBits new top bottom correction bits IPOL1 3 jpolBits format x x x IIPOL1 ITPOL2IIPOL3 x x fits to PCTL2 of MR32 dtStateFlagsAB internal dead time correction flags for phases AB dtStateFlagsC internal dead time correction flags for phase C pointA internal capture of the pointer for phase A pointB internal capture of the pointer for phase B pointC internal capture of the pointer for phase C po
26. ction motor brake set incorporates a 3 phase AC induction motor and attached BLDC motor brake The AC induction motor has four poles The incremental position encoder is coupled to the motor shaft and position Hall sensors are mounted between motor and brake They allow sensing of the position if required by the control algorithm Detailed motor brake specifications are listed in Table 3 4 In a target application a customer specific motor is used Table 3 4 Motor Brake Specifications Set Manufactured EM Brno Czech Republic Motor Specification eMotor Type 3 Phase Pane Motor Pole Number 4 Nominal Speed 1300 rpm Nominal Voltage 3 x 200 V Nominal Current 0 88 A Brake Specification Brake Type pe e Motor Nominal Voltage 3x27 V Nominal Current 2 6 A Pole Number 6 Nominal Speed 1500 rpm Position Encoder Type Baumer Electric BHK 16 05A 1024 12 5 Pulses per Revolution 1024 DRM019 Rev 0 Designer Reference Manual MOTOROLA Hardware Design For More Information On This Product Go to www freescale com 35 Freescale Semiconductor Inc Hardware Design 3 7 Hardware Documentation All the system parts are supplied and documented according to the following references U1 MC68HC908MR32 Control Board supplied as ECCTR908MR32 described in Motorola Embedded Motion Control MC68HC908MR32 Control Board User s Manual MEMCMR
27. d PVAL registers are not used When dead time correction is used the even PVAL registers are loaded with the desired PWM plus half of the dead time PWMx DT 2 while the odd PVAL registers are loaded with the desired PWM minus half of the dead time PWMx DT 2 Designer Reference Manual MOTOROLA System Description 21 For More Information On This Product Go to www freescale com System Description Freescale Semiconductor Inc Table 2 1 PWM values loaded into registers PVAL1 6 Phase PVAL pvaL without dead PVALwith dead time Actual values loaded into time correction correction phase oe he PNT ie DEAD AusIeMaPRES i Aa b PM ENTE EAO MERITE Phage i OAT ee DERD ap PRESS ee PWMa BI EROTIES Phase MAS EWM EMSL a EnO PIPN EBES ENARB il PMS Dia DER OTIPA PRES Designer Reference Manual When calculating the values to be loaded into the PVAL registers the MRxx s Dead Time register can be used The dead time register DEADTM holds an 8 bit value which specifies the number of CPU clock cycles to be used for the dead time when complementary PWM mode is selected Dead time is not affected by changes to the prescaler value On the other hand the PVAL values are affected by the prescaler of the PWM counter Therefore the value stored into the dead time register needs to be scalled by the PWM prescaler PWM_PRESC in Table 2 1 The PWM Control Regis
28. e 5 6 PC Master Software Control Window The PC master software displays the following information e required and actual speed of the motor e phase voltage amplitude related to given DC Bus voltage e application mode START STOP e DC Bus voltage e fault status Designer Reference Manual DRM019 Rev 0 58 System Setup MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Controlling the Application with PC Master Software The PC master software allows the user to e set the PWM frequency the frequency can be changed at any time during the motor operation 4kHz 8kHz 16 kHz 32 kHz e select dead time distortion correction the selection can be done at any time during the motor operation no partial full The PWM frequency and type of dead time distortion correction can be selected in both the manual and the PC master modes using the PC master software It is possible to use the oscilloscope to display the phase currents and voltages for dead time distortion evaluation DRM019 Rev 0 Designer Reference Manual MOTOROLA System Setup 59 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Designer Reference Manual DRM019 Rev 0 60 System Setup MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor
29. ectrical degrees until a high negative current can be expected Then State 5 is entered As soon as the low magnitude of positive current is detected the IPOL is changed to 0 requesting the odd numbered PWM registers to be used for PWM generation the actual value of the wave pointer is recorded 0c and State 6 is entered State 6 is preserved for 80 electrical degrees until a high positive current can be expected Then State 3 is entered and the state machine loop is repeated In this way it is ensured that the required IPOL changes when a small amplitude of respective current is detected by the hardware Please note that the wave pointer is recorded into the algorithm variable PointA PointB or PointC in the moment when the respective phase current crosses the low current threshold Designer Reference Manual DRM019 Rev 0 44 Software Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design Algorithm of Dead Time Distortion Correction Algorithm enabled INITIAL STATE 00 Initial recognition of positive current High positive current Low negative current X0 0 Waits for high Change IPOL Waits for high positive current current treshold negative current 6 gt 80 0 crossing e 6 gt 80 1 High negative Low positive current current 1X 1 STATE TRANSITION KEY DT1 DT2 IPOL IPOL 0 ODD NUMBERED PWM REGISTERS CONT
30. er Stage e Optoisolation Board e 3 phase AC Induction Motor The correct phase order phase A phase B phase C for the shown AC induction motor is e Phase A red wire e Phase B white wire e Phase C black wire DRM019 Rev 0 Designer Reference Manual MOTOROLA System Setup 49 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup If you view the motor looking into the shaft end and the phase order is phase A B C the motor shaft should rotate in a clockwise direction i e positive direction positive speed Induction motor a A s ii imie e E SC rTrRe Motor Power BSHCSOBMRS2 Connector f EVM Board A BSHCSCBMR32 evm board 3 ph AC BLDC Optoizelation fA Serial Cable Power Stage Board to PC ad Figure 5 1 Setup of the Application 5 3 Warning This application operates in an environment that includes dangerous voltages and rotating machinery Be aware that the application power stage and optoisolation board are not electrically isolated from the mains voltage they are live with risk of electric shock when touched Designer Reference Manual DRM019 Rev 0 50 System Setup MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Jumper Settings of Controller Board An isolation transformer should be used when operating off an AC power line
31. er data scaling is secured see Figure 4 3 40 Software Design For More Information On This Product Go to www freescale com DRM019 Rev 0 Freescale Semiconductor Inc Software Design Data Flow It is important to note that 50 PWM or 50 of PWM Modulus loaded to the corresponding PVAL registers corresponds to the ZERO phase voltage But in the wave table the ZERO phase voltage corresponds to the number 0x0000 Therefore the fetched wave value from the table must be added to the 50 PWM Modulation for quadrant 1 and 2 or substracted from the 50 PWM Modulation for quadrant 3 and 4 Thus the correct PWM value is loaded Ox7fff Actual Phase n A Phase Increment Actual Phase n 1 DutyCycle PhaseA 0x8000 180 0 Ox7fff 180 0x0000 Figure 4 3 mcgen3PhWaveSine Data Explanation Phase A The output parameters of the process are e PWM value for phase A PVAL1 register e PWM value for phase B PVAL3 register e PWM value for phase C PVALS5 register DRM019 Rev 0 Designer Reference Manual MOTOROLA Software Design 41 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design In case of dead time distortion correction the corrected PVAL values PVAL1 6 are calculated and used for the PWM generation according to the detected phase current polarity The process can be described by following points e Wave pointer for
32. ersonal injury or death may occur Should Buyer purchase or use Motorola products for any such unintended or unauthorized application Buyer shall indemnify and hold Motorola and its officers employees subsidiaries affiliates and distributors harmless against all claims costs damages and expenses and reasonable attorney fees arising out of directly or indirectly any claim of personal injury or death associated with such unintended or unauthorized use even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part MOTOROLA Motorola and the Stylized M Logo are registered in the U S Patent and Trademark Office digital dna is a trademark of Motorola Inc All other product or service names are the property of their respective owners Motorola Inc is an Equal Opportunity Affirmative Action Employer Motorola Inc 2003 DRM019 D For More Information On This Product Go to www freescale com
33. etrowerks Inc a wholly owned subsidiary of Motorola Inc DRM019 Rev 0 Designer Reference Manual MOTOROLA System Setup 53 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup If the MMDS target is selected CodeWarrior will automatically download to the MMDS05 08 emulator The application can operate in two modes 1 Manual Operating Mode The drive is controlled by the START STOP switch SW3 The direction of the motor rotation is set by the FWD REV switch SW4 The motor speed is set by the SPEED potentiometer P1 Refer to Figure 5 4 for this description Fault POT Forward Reverse Over Voltage r Switch SW4 Fault POT Fauteor Figure 5 4 Control Elements Designer Reference Manual DRM019 Rev 0 54 System Setup MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Executing the Application ni OL RED TAMODETSORERMERES It RESET Bog SPeocoesseeeenenceee z Button z Figure 5 5 USER LEDs PWM LEDs and RESET 2 PC Master Software Remote Operating Mode The drive is controlled remotely from a PC through the serial communications interface SCI communication channel of the MCU device via an RS 232 physical interface The drive is enabled by the START STOP switch which can be used to safely stop the application at any time Setting the required speed of the moto
34. f successful the 3 phase AC induction motor will be spinning If the START STOP switch is set to the START position when the application starts toggle the switch between the STOP and START positions to enable motor spinning This is a protection feature preventing the motor to start spinning when the application is executed from CodeWarrior You should also see a lighted green LED indicating the application is running If the application is stopped the green LED will blink at a 2 Hz frequency When the application is started the type of dead time distortion correction and desired PWM frequency can be selected using the PC master software control page The phase voltage and motor current can be observed using the oscilloscope and the efficiency of dead time distortion correction can be evaluated The type of dead time distortion correction is indicated by a yellow LED on MR22 controller board When the dead time distortion correction is disabled the yellow LED is turned off When partial correction is selected the LED flashes with 2Hz frequency With full correction the LED is turned on refer to Table 5 3 DRM019 Rev 0 56 System Setup MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Controlling the Application with PC Master Software Table 5 3 Dead Time Distortion Correction Distortion Correction Yellow LED State Disabled Off Part
35. ial h w Blinking at a frequency of 2Hz Full s w On 5 8 Controlling the Application with PC Master Software Project file for the PC master software is located in pcmaster 3ph_acim_dt_correct pmp Start the PC master software application window and choose the appropriate PC master software project Figure 5 6 shows the PC master software control window for 3ph_acim_dt_correct pmp The type of dead time distortion correction no partial full and the PWM frequency 4kKHZ 8kHZz 16kHz 32kHz can be selected in the variables pane as shown in Figure 5 6 NOTE The desired dead time can be set in application configuration file appconftig h where all on chip modules of the 6BHC908MR32 microcontroller are initialized DRM019 Rev 0 Designer Reference Manual MOTOROLA System Setup 57 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup Freescale Semiconductor Inc Designed By Motorola Czech Systems Laboratories Roznov p Radh Czech Repul MOTOROLA 3 ph ACIM Dead Time Distortion Correction on 68HC908MR32 pm is me 3000rpm 0 pm a STOP No fault Voltage power stage lt SSOW 1BOW a 3 000 rom i MOTOROLA digitaldna j control page akyarithm block description osciloscop Select no partial full dead ao e time distortion correction _ NO Dead Time Correction Patial Dead Time Correctio Full Dead Time Correction Figur
36. ime The zero voltage during dead time reflects a positive phase current the full DC Bus voltage during dead time reflects a negative phase current So comparing the phase voltage with the half DC Bus voltage enables an evaluation of the current polarity The topology is illustrated in Figure 2 4 The output of the comparator is connected to the current polarity sensing input of the MC68HC908MR32 microcontroller The microcontroller contains the hardware that samples the current sensing inputs during dead time It enables evaluation of the current polarity and also the region of low currents Designer Reference Manual DRM019 Rev 0 20 System Description MOTOROLA For More Information On This Product Go to www freescale com DRM019 Rev 0 Freescale Semiconductor Inc System Description Dead Time Distortion Correction U PWMO PWM1 Figure 2 4 Topology of Current Polarity Sensing During PWM reload ISR the desired PWM values for all three phases are calculated as e PWM1 for phase 1 e PWM2 for phase 2 e PWM for phase 3 The values loaded into the individual PVAL registers of the separate phases are shown in Table 2 1 Since AC motor control utilizes center aligned PWM modulation only half of the dead time needs to be added to substracted from the desired PWM duty cycle to achieve the distortion correction Without dead time correction the even PVAL registers are loaded with the required PWM value but the od
37. interA INPUT actual pointer of the generated wave phase A The dead time correction algorithm dtCorrectFull adds the correction factor to originally calculated sine wave It is necessary to ensure that the calculated PWM duty cycles do not exceed the PWM modulus The dtCorrectinit function must be called before starting any call to the dtCorrectFull function to ensure proper functionality DRM019 Rev 0 Designer Reference Manual MOTOROLA Software Design 47 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design Designer Reference Manual DRM019 Rev 0 48 Software Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC Section 5 System Setup 5 1 Contents 5 2 Hardware See 5iccsccdieaisri ei sneveswinknnses 49 et ee ohne sks Sh CRT eee eee 50 5 4 Jumper Settings of Controller Board 51 5 5 Required Software Tools 0 0 eee eee 52 5 6 Building the Application isccccessadewsesisascreensas 53 5 7 Executing the Application nnana anaana 53 5 8 Controlling the Application with PC Master Software 57 5 2 Hardware Setup Figure 5 1 illustrates the hardware setup of the application It incorporates the following modules e MC68HC908MR22 Control Board e 3 phase AC BLDC High Voltage Pow
38. ion Pai _ 50 w e dissipation PEREN 100 Total power dissipation Puiss 85 3 5 Optoisolation Board DRM019 Rev 0 Motorola s embedded motion control series optoisolation board links signals from a controller to a high voltage power stage The board isolates the controller and peripherals that may be attached to the controller from dangerous voltages that are present on the power stage The optoisolation board s galvanic isolation barrier also isolates control signals from high noise in the power stage and provides a noise robust systems architecture Signal translation is virtually one for one Gate drive signals are passed from controller to power stage via high speed high dV dt digital optocouplers Analog feedback signals are passed back through HCNR201 high linearity analog optocouplers Delay times are typically Designer Reference Manual MOTOROLA Hardware Design 33 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Hardware Design 250 ns for digital signals and 2 us for analog signals Grounds are separated by the optocouplers galvanic isolation barrier Both input and output connections are made via 40 pin ribbon cable connectors The pin assignments for both connectors are the same For example signal PWM_AT appears on pin 1 of the input connector and also on pin 1 of the output connector In addition to the usual motor co
39. mplitude of the motor voltage sine wave is calculated according to the desired speed using Volt per Hertz table The sine wave generator generates the PWM values for all three phases of the AC bridge inverter according to the selected type of dead time distortion correction algorithm The system incorporates the following hardware blocks e power supply rectifier e three phase inverter including optoisolation e feedback sensors DC Bus voltage DC Bus current temperature polarity of phase currents e microcontroller MC68HC908MR22 DRM019 Rev 0 Designer Reference Manual MOTOROLA System Description 15 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Description 3 phase AC Power Stage oO lt o a DC Bus Voltage Polarity of DC Bus Current Phase MC68HC908MR32 Temperature Currents Fault Protection START Ramp ea Correction E mar Sine PWM eima Disabled Generation State Partial ee Machine Full DOWN o Figure 2 1 System Block Diagram The drive is designed as a Volt per Hertz drive It means that the control algorithm keeps constant magnetizing current flux of the motor by varying the stator voltage with frequency The commonly used C Volt per Hertz ramp of a 3 phase AC induction motor illustrates Figure 2 2 Tl Designer Reference Manual DRM019 Rev 0 16 System Description MOTOROLA For
40. nces Appendix B Glossary DRM019 Rev 0 8 MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC DRM019 Rev 0 List of Figures Figure Title Page 2 1 System Block Diagram ccicscccaieesoisiviseseeadasds 16 2 2 Volt per Hertz Ramp ch setecd dian gecnaededeaduasd 17 2 3 Dead Time Distortion n anaua aeaaaee 19 2 4 Topology of Current Polarity Sensing 21 2 5 Proposed Current Threshold for Correction Toggling 24 3 1 Hardware Configuration eer edi sl dure ries ee wes 28 3 2 MC68HC908MR82 Control Board 200055 30 3 3 3 Phase AC High Voltage Power Stage 32 S DARA Fie ek cece re oe oe eed Ce ee ee ee 38 4 2 3 Phase Sine Waves with Amplitude of 50 40 4 3 mcgen3PhWaveSine Data Explanation Phase A 41 4 4 Dead Time Correction State Machine 45 5 1 Setup of the Application 0 cece eee 50 5 2 MC68HC908MR32 Jumper Reference 52 5 3 Execute Make Command i sei ied edad ewidweax rene be 53 5 4 Control Elements sannana naaa 54 5 5 USER LEDs PWM LEDs and RESET cscs cccacaccccun ce 55 5 6 PC Master Software Control Window 58 Designer Reference Manual MOTOROLA 9 For More Information On This Product Go to www freescale com
41. ntrol signals an MC68HC705JJ7CDW serves as a Serial link which allows controller software to identify the power board Power requirements for controller side circuitry are met with a single external 12 Vdc power supply Power for power stage side circuitry is supplied from the power stage through the 40 pin output connector The electrical characteristics in Table 3 3 apply to operation at 25 C and a 12 Vdc power supply voltage Table 3 3 Electrical Characteristics of Optoisolation Board Characteristic Symbol Min Typ Max Units Notes Power Supply Voltage Vdc 10 12 30 V Quiescent Current loc 70 20002 500 mA DC DC converter Min Logic 1 Input Voltage Vin 2 0 V HCT logic Max Logic 0 Input Voltage ViL 0 8 V HCT logic Analog Input Range Vin 0 3 3 V Input Resistance Rin 10 kQ Analog Output Range Vout 0 3 3 V Digital Delay Time toby 0 25 us Analog Delay Time tapLY 2 us 1 Power supply powers optoisolation board only 2 Current consumption of optoisolation board plus DSP EVM board powered from this power supply 3 Maximum current handled by DC DC converters Designer Reference Manual DRM019 Rev 0 34 Hardware Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc 3 6 Motor Brake Specifications Hardware Design Motor Brake Specifications The AC indu
42. ontrol boards and an optoisolation board it provides a software development platform that allows algorithms to be written and tested without the need to design and build a power stage It supports a wide variety of algorithms for both AC induction and brushless DC BLDC motors Input connections are made via 40 pin ribbon cable connector J14 Power connections to the motor are made on output connector J13 Phase A phase B and phase C are labeled Ph_A Ph_B and Ph_C on the board Power requirements are met with a single external 140 to 230 volt DC power supply or an AC line voltage Either input is supplied through connector J11 Current measuring circuitry is set up for 2 93 amps full scale Both bus and phase leg currents are measured A cycle by cycle over current trip point is set at 2 69 amps The high voltage AC power stage has both a printed circuit board anda power substrate The printed circuit board contains IGBT gate drive circuits analog signal conditioning low voltage power supplies power factor control circuitry and some of the large passive power components All of the power electronics which need to dissipate heat are mounted on the power substrate This substrate includes the power IGBTs brake resistors current sensing resistors a power factor correction MOSFET and temperature sensing diodes Figure 3 3 shows a block diagram DRM019 Rev 0 Designer Reference Manual MOTOROLA Hardware Design 31 For More Inf
43. or due to the limited switching speed of the transistors duty cycle A ratio of the amount of time the signal is on versus the time it is off Duty cycle is usually represented by a percentage interrupt A temporary break in the sequential execution of a program to respond to signals from peripheral devices by executing a subroutine input output I O Input output interfaces between a computer system and the external world A CPU reads an input to sense the level of an external signal and writes to an output to change the level on an external signal logic 1 A voltage level approximately equal to the input power voltage Voo logic 0 A voltage level approximately equal to the ground voltage Vss Designer Reference Manual MOTOROLA Glossary 63 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc MC68HC08 A Motorola family of 8 bit MCUs MCU Microcontroller Unit A complete computer system including a CPU memory a clock oscillator and input output I O on a single integrated circuit MR32 908MR32 MC68HC908MR32 See MC68HC08 phase locked loop PLL A clock generator circuit in which a voltage controlled oscillator produces an oscillation which is synchronized to a reference signal PVAL PWM value register of motor control PWM module of MC68HC908MR32 microcontroller It defines the duty cycle of generated PWM signal PWM
44. ormation On This Product Go to www freescale com Hardware Design Designer Reference Manual Freescale Semiconductor Inc HV POWER INPUT SIGNALS TO FROM CONTROL BOARD N BOARD ID BLOCK le a SWITCH MODE PFC CONTROL ll POWER SUPPLY de BUS BRAKE 3 PHASE IGBT POWER MODULE GATE DRIVERS PHASE CURRENT PHASE VOLTAGE BUS CURRENT BUS VOLTAGE MONITOR N 7 ZERO CROSS BACK EMF SENSE 3 PHASE AC TO MOTOR Figure 3 3 3 Phase AC High Voltage Power Stage The electrical characteristics in Table 3 2 apply to operation at 25 C with a 160 Vdc power supply voltage DRM019 Rev 0 32 Hardware Design For More Information On This Product Go to www freescale com MOTOROLA Freescale Semiconductor Inc Hardware Design Optoisolation Board Table 3 2 Electrical Characteristics of Power Stage Characteristics Symbol Min Typ Max Units DC input voltage Vdc 140 160 230 V AC input voltage Vac 100 208 240 V Quiescent current lcc 70 mA Min logic 1 input voltage Vin 2 0 V Max logic 0 input voltage Vit E 0 8 V Input resistance Rin 10kQ Analog output range Vout 0 3 3 V Bus current sense voltage Isense 563 mV A Bus voltage sense voltage VBus 8 09 mV V Peak output current IpK 2 8 A ea dissipat
45. r is the supported control action The application states are displayed with on board LEDs Refer to Figure 5 5 for the LED positions If the application runs and motor spinning is disabled i e the system is ready the green status LED will blink When motor rotation is enabled the green status LED will be on and the actual state of the pulse width modulator PWM outputs are indicated with PWM output LEDs labeled PWM1 PWM6 If DC Bus over current DC Bus over voltage occurs or if the wrong system board is identified the green status LED will start to flash quickly and the PC master software will signal the identified fault This state can be exited only with the application reset DRM019 Rev 0 Designer Reference Manual MOTOROLA System Setup 55 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc System Setup NOTE Designer Reference Manual Refer to Table 5 2 for a description of the application states and their corresponding LED indications Table 5 2 Motor Application States Application State Motor State Green LED State Stopped Stopped Blinking at a frequency of 2Hz Running Spinning On Fault Stopped Blinking at a frequency of 8Hz Once the application is running e Move the START STOP switch SW3 from STOP to START e Select the direction of rotation by the FWD REV switch SW4 e Set the required speed by the SPEED potentiometer I
46. rity For phase 2 bits DT3 and DT4 are used For phase 3 bits DT5 and DT6 are used As was stated the determination of the correct PVAL used for the PWM generation is done purely by software The on chip dead time correction block is set in the manual mode current sense correction bits ISENS1 ISENSO of PWM Control Register 0 PCTL1 are set to 00 or 01 Designer Reference Manual MOTOROLA System Description For More Information On This Product Go to www freescale com 25 Freescale Semiconductor Inc System Description Designer Reference Manual DRM019 Rev 0 26 System Description MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC Section 3 Hardware Design 3 1 Contents 3 2 System COMIQUIAION 0 ids deci cadsesdebdseeeaceee ddan 27 3 3 MC68HC908MR82 Control Board 05 29 3 4 3 Phase AC BLDC High Voltage Power Stage 31 3 5 Optoisolation Board o 6ccscriekedascaunccks cae awe ee eae 33 3 6 Motor Brake Specifications 00 eee ee eens 35 of Hardware Donets lt u ierad cider aeene verses 36 3 2 System Configuration The application is designed to drive the 3 phase AC motor It consists of the following modules see Figure 3 1 e MC68HC908MR22 Control Board e 3 phase AC BLDC High Voltage Power Stage e Optoisolation Board e 3 pha
47. ry f 2003 1 Initial version N A Designer Reference Manual DRM019 Rev 0 4 MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC List of Sections For More Information On This Product Go to www freescale com Section 1 Introduction 0000 cee eee eee 13 Section 2 System Description 0000000 15 Section 3 Hardware Design 2 0 0 05 27 Section 4 Software Design 5 37 Section 5 System Setup ccc eee eeee 49 Appendix A References 0000cee ee eneee 61 Appendix B Glossary 0000c eee ences 63 DRM019 Rev 0 Designer Reference Manual MOTOROLA Freescale Semiconductor Inc List of Sections Designer Reference Manual DRM019 Rev 0 6 MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Designer Reference Manual 3 ph ACIM Drive with DTC DRM019 Rev 0 1 2 1 3 2 1 2 2 2 3 3 1 3 2 3 3 3 4 3 5 3 6 3 7 4 1 4 2 4 3 Table of Contents Section 1 Introduction COMETE sete Ash ce ey es cee es ee ace 13 Application FUNCHONANY 2 2 2 sede dwanec se sewedan 13 Benefits of the Solution 020 0 eee eaee 13 Section 2 System Description Ole ae Sok ohne eh a onc ee ee ee he 15 System CONCS
48. scribed in terms of e Software Data Flow e Algorithm Dead Time Distortion Correction 4 3 Data Flow The requirements of the drive dictate that software takes some values from the user interface and sensors processes them and generates 3 phase PWM signals for motor control The control algorithm of closed loop AC drive is described in Figure 4 1 It consists of processes described in the following sub sections The dead time distortion correction algorithm is described separately in the successive section DRM019 Rev 0 Designer Reference Manual MOTOROLA Software Design 37 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design SCI Communication Process PC Master Software Control Switches A D converters omega_reqPCM_mech Process Speed Command dtCorrectOption Current Polarity Process Sensing Status Control Process Dead Time Distortion Correction u_dc_bus omega_reqOMP_mech Process Acceleration Deceleration Ramp appFaultStatus omega_reqRMP_mech pDtCorrectApp Process Fault Control A Process V Hz Ramp u_ramp phase_increment Process PWM Generation PVAL1 2 PVAL3 4 PVAL5 6 Figure 4 1 Data Flow Designer Reference Manual DRM019 Rev 0 38 Software Design MOTOROLA For More Information On This Product Go to www freescale com Freescale Semiconductor Inc
49. se AC Induction Motor DRM019 Rev 0 Designer Reference Manual MOTOROLA Hardware Design 27 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Hardware Design dEUNB806DH899WN pieog 4a 019U05 TA aiqeo uoqqH el MOp p p uuo JON p p uuo JON OVAIHULWOS BEE l T Ig ns GIG OVAIH1dOD OvOS SS e1g 1070W a 2 ovadb OOF 1d003 a T z peog te kher 62 S 1 MOd dd uonejosio doO abeyon YIH Zm N C d Trg EN oma ov ude 1 uoqqu IU MOP GND DAACT Figure 3 1 Hardware Configuration DRM019 Rev 0 Designer Reference Manual MOTOROLA Hardware Design For More Information On This Product 28 Go to www freescale com Freescale Semiconductor Inc Hardware Design MC68HC908MR2z2 Control Board 3 3 MC68HC908MR32 Control Board Motorola s embedded motion control series MR32 motor control board is designed to provide control signals for 3 phase AC induction 3 phase brushless DC BLDC and 3 phase switched reluctance SR motors In combination with one of the embedded motion control series power stages and an optoisolation board it provides a software development platform that allows algorithms to be written and tested without the need to design and build hardware With software supplied on the CD ROM the control board supports a wide variety of algorithms for AC induction SR and BLDC motors User control
50. ter 2 PCTL2 contains the PWM generator prescaler The buffered read write bits PRSCO and PRSC1 select the PWM prescaler according to Table 2 2 Table 2 2 PWM Prescaler A eae PESCO PWM Frequency Prescaler PWM_PRESC 00 fop 1 01 fop 2 2 10 fop 4 4 11 fop 8 8 DRM019 Rev 0 22 System Description For More Information On This Product Go to www freescale com MOTOROLA DRM019 Rev 0 Freescale Semiconductor Inc System Description Dead Time Distortion Correction The on chip PWM module of MC68HC908MRxx microcontrollers enables them to perform two types of dead time distortion correction e Partial correction e Full correction Partial dead time distortion correction is based only on polarity detection of phase current The hardware sensing the current polarity according to Figure 2 4 needs to be implemented The software is responsible for calculating both compensated PWM values and placing them in an odd even PWM register pair according to Table 2 1 The distortion correction is fully implemented by the on chip PWM module according to the following scheme e lf the current sensed at the motor for that PWM pair is positive voltage on current pin ISx is low the odd PWM value is used for the PWM pair e Likewise if the current sensed at the motor for that PWM pair is negative voltage on current pin ISx is high the even PWM value is used For partial correction
51. uct Go to www freescale com Freescale Semiconductor Inc System Setup Building the Application e Metrowerks CodeWarrior 2 for MC68HCO8 microcontrollers version 1 2 or later e PC master software version 1 2 0 11 or later 5 6 Building the Application To build this application open the 3ph_acim_dt_correct mcp project file and execute the Make command see Figure 5 3 This command will build and link the motor control application along with all needed Metrowerks libraries jMetrowerks CodeWarrior File Edit View Search Project Debug Window Help a a E K Add Window Add Files 3ph_AC_ Hz mcp Create Group e ms Greate Target W MM Greate Seqment Overlay Files Link Order Tar cher syntax Chri Walters e r A Precompile EEA Dependencies cae x BE SDK Configu ARIE GOTT WM appconfig Disassemble Gri ESRI M config c MM bspcontig __Bring Up To Date Ctrl U E interrupts c M sys c Stop Build Gtrl Breatk H C Sources 9 ASM Sources Remove Object Code Ctrl Figure 5 3 Execute Make Command 5 7 Executing the Application To execute the motor control application in the pull down menu choose the Project Debug command in the CodeWarrior IDE followed by the Run command 1 Metrowerks and the Metrowerks logo are registered trademarks of Metrowerks Inc a wholly owned subsidiary of Motorola Inc 2 CodeWarrior is a registered trademark of M
52. veSine function calculates an immediate value of the three phase sinusoidal system from given amplitude and actual phase pointer e Phase A sPhaseVoltage PhaseA Designer Reference Manual MOTOROLA Software Design 39 For More Information On This Product Go to www freescale com Freescale Semiconductor Inc Software Design Designer Reference Manual e Phase B sPhaseVoltage PhaseB e Phase C sPhaseVoltage PhaseC The individual waves are shifted 120 each other The shape of the generated waveforms depends on the data stored in the sine table In motor control applications data usually describes a pure sinewave or a sinewave with addition of the third harmonic component Figure 4 2 shows the duty cycles generated by the mcgen3PhWaveSine function when amplitude is 50 DutyCycle PhaseA DutyCycle PhaseB DutyCycle PhaseC 0 0 E ee ENEN E ESEESE TENNENE E ET CEE e E ETETE Figure 4 2 3 Phase Sine Waves with Amplitude of 50 The calculation is based on the wave table stored in FLASH memory of the microcontroller The table describes either a pure sinewave or a sinewave with the third harmonic addition The second case is often preferred because it allows one to generate the first harmonic sine voltage equal to the input AC line voltage The format of the stored wave table data is from 0x0000 for ZERO Voltage up to Ox7fff for the 100 Voltage Thus the prop

DRM019, 3-Phase AC Induction Motor Drive with Dead Time

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