New transformer-assisted resonant DC link topology and its application for three-phase voltage-FED ZVS-PWM sinewave inverter using instantaneous space voltage vector modulation

The newly-proposed Resonant DC Link (RDCL) topology operating under the high-frequency trans-former-assisted zero-voltage soft switching commutation principle is presented in this paper. This basic circuit operating principle and the optimum design procedure for Transformer-Assisted Quasi-Resonant DC Link (TQRDCL) which excludes its load current sensing-based predictive feedback control loop and the DC voltage-clamped PWM function are considered as compared with the conventional RDCL circuit topologies. The performance of three-phase ZVS-PWM inverter system is discussed and evaluated in terms of the comparative study between TQRDCL three-phase soft-switching PWM type and conven-tional three-phase hard-switching PWM inverter systems on the basis of the simulating and experimental results.