A pulse current regenerative auxiliary resonant bridge leg link snubber-assisted three-phase soft switching PWM inverter

In this paper, a novel circuit topology of active auxiliary edge resonant snubber suitable for high power soft switching PWM inverter applications, which has some salient features as compared with previously developed auxiliary resonant commutated pole (ARCP) snubber is proposed in order to minimize the switching power losses of IGBTs in addition to the switching surge related electromagnetic noises in three-phase power conversion circuits on the basis of the sinewave PWM inverter and sinewave PWM PFC rectifier as well as bi-directional PWM converter used as the battery energy storage system. This resonant snubber-assisted inverter suitable for high power conversion is described and discussed on the basis of soft switching transition and commutation operation of the high efficient pulse modulated inverter. The working principle and operating characteristics of this active auxiliary snubber circuit are described, together with the practical design procedure of this unique edge resonant snubber. This paper shows actual efficiency vs. output power characteristic of three-phase soft switching PWM double converter system designed for 10 kVA UPS composed of three phase soft switching PWM rectifier and inverter. The total actual efficiency of three phase soft switching PWM double converter is 88.6% as compared with that of hard switching double converter is 87.0% under a rated load.