A: GD350-185G-4， 

Application condition: Speed regulation of synchronous motor powder selection machine. 

Fault phenomenon: There is abnormal noise and mechanical vibration from the motor during startup, which is reported as STo.

 How to solve it?

Cause analysis: 

Check that the motor parameter settings are correct. 

Check the synchronous motor magnetic pole detection P13.01=2, P13.06=80%. 

Observe that the current is unstable during operation.

Solution: 

Optimize P13.06 to eliminate motor abnormal noise at the moment of starting after 30%. 

Optimize the speed loop control parameters of P3 group. 

Improvement effect: 

smooth start stop and stable operation.