I'm currently designing a variable frequency drive for powering an AC induction motor.
I've three 400V/680µF electrolytic caps for smoothing the 325V (nominal) DC bus.
Then the DC bus is chopped by the inverter and fed into the AC motor (which is a very inductive load, with a lot of dv/dt generated during switching).
My question is putting two TVS diodes at the end of the cap bank is useless or not? Can it provide somehow a "clamp" against these voltages spikes and protect the caps?
TD1 and TD2 are Littelfuse 1.5SMC510CA TVS diodes.