FOC command is sometimes stuck

[Quentin Ch]

Hello,

I'm controlling a BLDC motor with MCSDK 6.0.0 and IHM08M1, with FOC with 1024 PPR encoder. I compute torque (Iq_ref) commands to achieve speed control, this works ok except in rare case described below:

Sometimes the MCSDK seems "stalled":

• I send a torque (Iq_ref) command, but the motors does not run
• The motor can mechanical spin freely (not blocked, I can spin it manually). Even I I release completely the load, is does not spin.
• Encoder feedback is ok (the MCSDK return a speed if I turn the motor manually)
• The PI current loop and the PWM regulation seem running since the read Iq value oscillates around the Iq_ref I set. Some current is flowing since the MOSFET are a little (be reasonably) hot.
• No fault flag is set
• Resetting the controllers solves the issue.

Why such behaviour could appear ?

Any clue ?

NB: this seems to occurs when I set a torque command to move the motor starting from 0 rpm.

Thanks,

[GMA]

Hello,

Did you check that, after your torque (Iq_ref) command, the internal I_Q_REF register is set accordingly? You can display it with the motor pilot register tab...

What is the control board type?

Best regards.

GMA