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TMS320F28069F: [28069F] when using motorware lab01c example, overcurrent trip is happened at start.

Hae Ryong Jung
Expert 2150 points

Part Number: TMS320F28069F
Other Parts Discussed in Thread: MOTORWARE

Dear TI members,

I am trying to develop FOC function step by step with motorware examples.

however I have encountered problem with lab01c example with custom board of 28069F to drive  ACIM motor.(1.5kW, 380V 3-phase input)

when I started to run motor by setting gMotorVars.Flag_enableSys and gMotorVars.Flag_Run_Identify to be 1,  then overcurrent trip happened by IPM. (just gMotorVars.SpeedRef_krpm = 0.3 krpm)

I want to see variables with CCS debug, but It is not possible for overcurrent.(I must turn off the board for further damage)

when I tried with lab01b, current was around 400mA, motor is running OK for 10Hz ~ 60Hz, and Motor's rated current is 3.4A and no load current is 2.0A (I am using motor parameters from motor company, and believe all parameters are correct)

If I could avoid overcurrent at startup, then I can trace variables with debug of CCS.

Would you please let me know which parameter might be checked to avoid overcurrent at startup ? (or let me know how to debug this situation)

if you need more information about the issue, just let me know.

Thanks in advance.

Hae Ryong

  • 0
    TI__Guru** 116930 points

    1. Please use lab01v to test the PWM and ADC modules for hardware first, the motor should run smoothly and sampling current should be showed in datalog as on scope.
    2. Please ensure the sign of "current_sf" is right in HAL_readAdcData( ) according to hardware board.
    3. Please make sure that the USER_ADC_FULL_SCALE_CURRENT_A, USER_ADC_FULL_SCALE_VOLTAGE_V and USER_VOLTAGE_FILTER_POLE_Hz is configured correctly based on hardware board.
    4. Please change the "gMotorVars.IqSet_A" based on motor rated current, set it to 20% value of motor rated current first.

  • 0 in reply to Yanming Luo
    Expert 2150 points

    Dear Mr. Yanming

    Thanks for your feedback.

    As your recommendation, I'd better to go on one by one.

    At first, I have tried verifying current feedback with Lab01b.

    current waveform is captured via datalog module, my board have 2 current feedback (V, W)

     datalog.iptr[0] = &gAdcData.I.value[0]; // V current

     datalog.iptr[1] = &gAdcData.I.value[1]; // W current

    it is captured for gMotorVars.SpeedRef_krpm = 1.8 krpm

    my modification for user.h is as follows (I leave verifying voltage feedback for lab1c at this moment)

    #define USER_IQ_FULL_SCALE_CURRENT_A          (14.9058)

#define USER_ADC_FULL_SCALE_CURRENT_A        (39.66)

#define USER_NUM_CURRENT_SENSORS            (2) 

#define I_A_offset (1.333306)
#define I_B_offset (1.333306)
#define I_C_offset (1.333306)

    I have tested for 0.3 ~ 1.8 krpm, no overcurrent happened, motor runs smoothly, looks OK.

    but measured current is too small, no load current of motor is 2A, but it shows around 400mA (rms) from Osciloscope.

    my question for this step is what could limit current than proper value.

    please let me know your insight.

    Best Regards,

    Hae Ryong

  • 0 in reply to Hae Ryong Jung
    TI__Guru** 116930 points
    What measured current is too small? Read from datalog/expression? Or look at from Oscilloscope? The value of both two should be similar. It seems the current waveform in datalog graph is perfect good, so may you check the hardware board to verify whether the USER_ADC_FULL_SCALE_CURRENT_A is calculated correctly and Flag_enableOffsetcalc is set to "true".
  • 0 in reply to Yanming Luo
    Expert 2150 points
    Sorry for confusing you.

    Measured current by Oscilloscope and current read from datalog is almost same, so I believe current_sf and offset are set correctly.
    The issue I am concerned is that actual current is too small(400mA) than no load current(2A) in motor specification.

    what do you think makes this difference ?

    Best Regards,
    Hae Ryong
  • 0 in reply to Hae Ryong Jung
    TI__Guru** 116930 points
    What motor types are you controlling? ACI or PMSM? It's ok if the motor is PMSM. This lab is just used for h/w verification, you may move on.
  • 0 in reply to Yanming Luo
    Expert 2150 points

    sorry for late response.

    motor type is ACI, what is your concern for ACI motor ? (380V, 3phase, 4 poles)

    I'm still thinking there is something wrong with the test. please let me know your idea about small current.

  • 0 in reply to Hae Ryong Jung
    Expert 2150 points

    would you please take a look at following capture ?

    I have got 70 samples of phase current and voltage from starting motor with CCS debugger, and draw graph with them.

    upper 2 graphs are  captured from TMDSHVMTRKIT with reference motor, looks OK.

    lower 2 graphs are from my custom board.

    as you may see, PID make current and voltage to be stable state in upper graph, but current is rapidly increased in lower graph just within 70 samples and cause IPM fault soon.

    what could make this situation?  PID seems not working correctly.

    please let me know what need to be investigated.

    Thanks in advance.

  • 0 in reply to Hae Ryong Jung
    Expert 2150 points
    Thanks anyway.

    The issue is closed.