独立光伏照明系统中的逆变器续流与抑制

Freewheeling Current and Suppression in Inverter of Stand-Alone Photovoltaic Lighting System

分析了独立光伏照明系统中感性和容性负载的串并联谐振逆变电路时开关管死区内的续流特性.用高次谐波的感性电流抵消基波容性电流,可减小串并联谐振开关管死区内的续流,抑制系统的谐波成分和电磁干扰,提高功率因数.实验结果表明,采用上述方法,使独立光伏照明系统的串并联谐振电路的续流值减小到约67 mA.

Freewheeling current during dead-time of two switching transistors was analyzed. The switching transistors work in a series-parallel resonant inverter circuit of a stand alone photovoltaic lighting system with inductive or capacitive loads. A method to suppress the freewheeling current was proposed. The method uses high-order inductive harmonic current to compensate capacitive fundamental current. It also reduces the harmonic component in current and electromagnetic interferences, and improves the power factor. Experiments show that the freewheeling current suppressed with the proposed method is as low as about 67 mA.