TMS320F28062F: Motor would be unstable under high and transient load

Young Hu

Part Number: TMS320F28062F
Other Parts Discussed in Thread: MOTORWARE

Hi Champs,

My customer is using F28062F and Instaspin for pump drives. The motor type is PMSM, and speed control was used, and motorware's version is v17. The motor parameter is gotten from motorID as follows. And all the PID parameter were calculated by InstaSpin.

Rs 0.4032

Ld 12.43

Flux 1.31

And they found when high and transient load was implemented, they motor would be unstable and unrecoverable. When phase current was increased to 28A, then motor would be out of control with big vibration. You can find the scope captures as follows. They tried to tune the PI parameters, and no any improvement.

Would you kindly help to suggest what the root cause? Another information is if they lower the Ls value manually, the motor would be keep stable with decreasing speed.

Thanks.

Young

over 9 years ago

0 Yanming Luo over 9 years ago

TI__Guru** 117160 points

1. Is input voltage enough for high speed, whether the high speed running need to use field weakening control?
2. Did customer have the Ls per Current profile? Some motor, the Ls will decrease very obviously with current increasing, if yes, you have to add a online Ls modification function.

0 Young Hu over 9 years ago in reply to Yanming Luo

TI__Expert 4185 points

Yanming,

The voltage is enough, because the motor can spin to the target speed.

Yes, looks Ls decreased with higher current, I will ask them to add Ls compensation.

Thanks,

Young

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28062F: Motor would be unstable under high and transient load