The State-of-Art Space-Voltage Vector Modulated Sinusoidal Three-Phase Inverter with High-Frequency Transformer-Coupled Resonant DC Link for High-Power Density UPS

Newly-improved Quasi-Resonant DC Link (QRDCL) three-phase voltage-sourced inverter circuit topology operating under a commutation principle of the high-frequency (HF) transformer-assisted Zero Voltage Switching (ZVS) is proposed. 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 presetted in this paper, Its operating characteristics are discussed and evaluated in terms of using the computer-aided simulating results. The experimental circuit is tested and examined for CVCF/UPS systems. This tested equipment is discussed for linear and non-linear electrical loads under the conditions of large load variations and voltage fluctuations from a practical point of view.