Active edge-resonant DC link snubber-assisted three phase soft switching inverter for AC servo drive

This paper presents an auxiliary active quasi-resonant DC link snubber-assisted three phase voltage source type soft-switching inverter for AC servo motor drive applications. The operation of this quasi-resonant DC link snubber circuit and its circuit parameter design method are described and three phase voltage source soft switching inverter using a quasi-resonant DC link snubber treated here is evaluated and discussed from an experimental point of view. In addition to these, the motor current and the motor speed response under the soft switching are compared with that of the conventional hard switching condition. The effectiveness of the soft switching inverter-fed permanent magnet AC servo motor drive system is proven by the common mode current in the inverter driven motor side and the conductive noise in the mains terminal interface voltage as compared with those of the conventional hard switching inverter-fed permanent AC servo motor drive system.