摘要

A topology of coupled inductor double boost inverter (CIDBI) is proposed based on the photovoltaic micro-inverter module system. The operation principle and control strategy of CIDBI are analyzed in detail and the gain expression from DC side to AC side is deduced. It can generate an AC output voltage much larger than the DC input one, depending on the proper setup of instantaneous duty cycle and turn ratio of the coupled inductors. Firstly, based on a given driving signal series, the operational principle of CIDBI is discussed. Secondly, the voltage stress of switches in CIDBI and the relationship between input and output are analyzed. The gain is approximately proportional to the duty cycle when the duty cycle is around 0.5 and the sinusoidal pulse width modulation (SPWM) is applicable to this novel inverter. Finally, the proposed CIDBI serves as a grid-connected inverter in a photovoltaic generation system. Experimental results show that the CIDBI can competently implement the single-stage grid-connected generation of photovoltaic system with a low level total harmonic distortion of current and high efficiency, without traditional transformer and DC/DC converter.

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