I am using the InstaSpin FOC with the 28069M. The PWM frequency is 15kHz. I am running a 600 watt PMSM motor with 380 volt DC bus. Everything is working fine except I get a lot of radiated emissions from the motor cable (30MHz to 150MHz). I put a 1000pF 2000 volt surface mount (1206) capacitor on each the U, V, and W outputs of the IGBT module going to the motor. I placed them right at the U,V,W pins of the IGBT module. Each went directly to the power GND. This seemed to help my radiated emissions coming out of the motor cable. I have seen this done on low voltage motor drives, but have not seen any high voltage examples. I feel I need to put some limiting resistor in series with each capacitor, but not sure if its really needed or what value would be needed. I usually see a 10 ohm resistor with the low voltage drives.
Wondering if anyone has seen this done on high voltage motor drives? Just making sure the capacitors are not being stressed. Or if there are any other suggestions or tricks to try for PCB emissions.
