Resonant DC link snubber-assisted soft switching inverter type AC servo driver with low common mode current characteristics

This paper presents an auxiliary active quasi-resonant DC link snubber-assisted three phase voltage source type soft-switching inverter used for the AC servomotor drive applications. At first, the operation of this quasi-resonant DC link snubber circuit and its circuit parameter design method are described. In the second place, three phase voltage source soft switching inverter using a quasi-resonant DC link snubber topology treated here is discussed and evaluated from an experimental point of view. Finally, its common mode current on the inverter driven motor side is evaluated for soft-switching inverter-fed permanent magnet AC motor drive system and compared with that of the conventional hard switching inverter system.