Why the output from Alpha Beta to D,Q block is not in DC???

Greetings to all, I am implementing FOC for PMSM drive in real time setup with f28377s processor part of it and generating code using embedded coder MATLAB2017a. To generate three phase, six pulse PWM, I need D-axis and Q-axis current. I am measuring that with current sensors as Ia and Ib and converting it into Ialpha and Ibeta and then to Id and Iq. Expected converted output should be a DC quantity. But the one I am getting is AC. When i used the normal transformation block other than the one from embedded coder the output was correct. Please help me to understand this situation. Thanks Best Regards Priya

[JANARDHAN GURRAM]

Hi Priya Sundaram

I am struggling with same

I am getting same AC output instead DC in d, q profiles ( ofcourse , I am implementing SIMULINK not hardware)

Do you found what was ther reason

Can U pls help me Why they r AC ?

Janardhan

Answer 1

[John Noon]

If you are not getting a steady output on the DQ side this means that the angle input to the transformation is wrong. If you double check the angle this should fix the issue. It is hard to see what the error is without seeing the model, but this is the root cause.