系統連系高周波2石フライバックトランス絶縁方式ソフトスイッチングPWM正弦波インバータ

Abstract

This paper presents two novel prototypes of the utility AC power source connected sinewave inverter using the high-frequency two-switch flyback transformer which is more suitable and acceptable for the small-scale solar photovoltaic and fuel cell generator interfaced power conditioners. The proposed sinewave soft-switching PWM power conditioner with a high-frequency AC link has a function of electrical isolation including sinewave hard-switching PWM power conditioner with a high frequency link, which is considered for solar photovoltaic power conditioner and fuel cell generator related power conditioner from the viewpoints of safety and reliability in total system. The discontinuous conduction mode (DCM) operation of the flyback transformer in this circuit system is also introduced to feature a simple, low-cost and high-efficiency topology of the sinewave inverter circuit and digital control implementation. The operating principle of the proposed sinewave soft-switching PWM inverter circuit as compared with sinewave hard-switching PWM inverter are described for the designing of circuit parameters. Moreover, the digitally controlled sinewave PWM control processing scheme is presented herein. Finally, the sinewave soft-switching PWM inverter prototype is actually built and tested to verify the validity of the proposed power conditioner for new energy generation systems.