A novel space-voltage vector modulated sinewave three-phase inverter with high-frequency transformer-coupled resonant DC link

A novel type of quasi-resonant DC link (QRDCL) three-phase voltage-sourced inverter circuit topology operating under a commutation principle of the auxiliary high-frequency (HF) transformer-assisted zero voltage switching (ZVS)-PWM is presented. The basic operating principle of this power conversion circuit using auxiliary transformer-assisted QRDCL (TQRDCL) more suitable for CVCF/UPS, power active filter, switched-mode PWM converter, and new energy-interfaced power supplies for utility-interactive interconnection, is presented in this paper. Its operating characteristics are discussed and evaluated in terms of using the computer-aided simulation results. The experimental inverter circuit is tested and examined for CVCF/UPS systems on the basis of the hard switched PWM inverter. This tested equipment is discussed for linear and nonlinear electrical loads under the conditions of large load variations and voltage fluctuations from a practical point of view