Three-phase bridge power block module type auxiliary resonant AC link snubber-assisted soft switching inverter for distributed AC power supply

This paper presents a novel prototype of the three-phase power module bridge package type auxiliary resonant AC link snubber circuit for the three-phase voltage source type sinwave soft switching PWM inverter operating under instantaneous space voltage vector modulation scheme. The operating principle of a novel prototype resonant AC link snubber circuit in addition to unique features are described for current source load model during one switching period which is equivalent to the three-phase voltage source type inverter with LPF, along with its design approach based on the simulation data. The steady-state performance evaluations of space vector modulated three-phase voltage source type sinewave soft switching inverter incorporating a new prototype circuit of three-phase active auxiliary resonant AC link snubber is illustrated and discussed as compared with those of three-phase voltage source type sinewave hard switching PWM inverter with a space voltage vector modulation strategy. The power loss analysis and conventional efficiency estimation of the three-phase voltage source soft switching PWM inverter using IGBT power modules is actually evaluated and discussed on the basis of the conduction power losses based upon the measured v-i characteristics for in addition to all the switching power losses of IGBT with antiparallel diode.