PMSM current controller Vph max limit

Hello,

In the PMSM FOC model, Inside the current loop, Vph max input to the current controller is given as Vdc/(root 3) . Is there a specific reason for using this value or is it dependant on what control scheme you are using . Incase im using SVPWM control what value should i use as Vph max .

Thank you

Answer 1

[Sabin]

Hi, VphMax is dependent on the modulation technique used. If we have Space Vector Modulation the maximum amplitude of the phase voltage is Vdc/sqrt(3). If we have Sinusoidal Modulation then VphMax=Vdc/2. The maximum amplitude can be increased in the overmodulation region, for example in six-step operation we can get (2/pi)*Vdc. I hope this helps.