The role of integrated passive components in protecting motor windings

Switching transients arising from the operation of power electronic switches in inverters supplying variable speed motors may lead to damage in the motor insulation and bearings. Filters between inverter and motor can alleviate the burden. The stator laminations can be used to form a capacitor. Toroidal windings through the bottoms of the slots with return round the back of the core form an inductor. The capacitor and inductor thus created and connected as a filter reduce the peak voltage on the machine terminals.