Advanced Single-Stage Soft Switching PWM Power Conditioner with Coupled Inductor PWM Boost Chopper Cascaded PWM Inverter and Time-Sharing Sinusoidal Follow-Up Control Scheme

This paper presents an advanced one-stage power conditioner circuit configuration suitable and acceptable for new energy generation systems specially low voltage large current distributed power supplies as solar photovoltaic and fuel cell or new storage applications as electric double layer capacitors and new type batteries. The circuit configuration depends mainly on eliminating the unreliable electrolytic capacitor DC link and using a bypass diode and coupled inductor assisted boost chopper to increase the boosting ratio and achieving high power conversion efficiency. This power conversion system is a modified version of the DC-DC converter previously proposed by the authors, which is composed of a time-sharing operated sinewave absolute modulated bypass diode and coupled inductor assisted boost chopper to produce a sinewave absolute value tracking AC voltage at the DC link and a sinewave PWM cascaded inverter to produce the sinusoidal AC voltage. This power conditioner is operated by selective time-sharing dual mode pulse pattern signal processing control scheme. The paper discusses also the soft switching operation of the coupled inductor boost chopper using only a passive auxiliary edge-resonant snubber circuit for further improvement in the total power conversion efficiency. The operating principle and the unique features of this new power conditioner are described and evaluated through a design example based on simulation results