Field-oriented PMSM control, Motor constant at 50rpm no matter the input

Hi guys,

I am currently trying to simulate a PMSM AC Motor in simscape. Using already existing blocks in simscape i made the whole simulation kinda work, but only kind of. No matter the input speed in the FOC the motor will "speed" up to 50 rpm and then not go further. Higher load means slower rise time but still stops rising at 50 rpm. (Please set the Inertia Block to the variable J, because right now it is 100*J and it slows down the simulation).

RIght know i am guessing it is the inverter because it doesn't output enough power. So far i didn't find a way to solve this. Maybe one of you can help me with this. I am happy to take any tips, which part it may be or how i could realize this in Simscape or just what the next step could be.

Thanks in advance

Answer 1

[Sabin]

First, the off-state conductance in the Converter (Three-Phase) block is too big. I would use something like 1e-4 to start with. Then, the controllers are not properly tuned. Trying with something like Kp=0.23 and Ki=17.5 in the d-q current controllers and Kp_speed=100 in the outer loop speed control will result in speed following the reference. I hope this helps.