Takeshi Kitaizumi

Utility-interactive solar power conditioner using high-frequency sinewave modulated inverter for distributed small-scale power supply

The utility interactive sinewave soft commutation inverter using IGBTs for solar photovoltaic power conditioner with a high frequency transformer is presented for residential applications. As compared with the conventional full-bridge hard switching sinewave PWM inverter with a high frequency link, the simplest single-ended quasi-resonant soft switching sinewave inverter with a sinewave duty cycle control scheme is developed, resulting in size and weight reduction, low-cost and efficiency. This paper presents a prototype system of the sinewave ZVS-PWM inverter for solar power generator, along with its operating principle and unique features. In addition to these, this paper discusses a control implementation to deliver high quality output current to be injected into the utility 1φ AC. The power loss analysis under actual power conditioning and processing is also discussed and evaluated from an experimental point of view. A compact utility-interactive sinewave power conditioning circuit which achieves 92.5% efficiency under 4 kW output is demonstrated.