High-reliability single-phase current source inverter with switching-cell structure for grid-connected photovoltaic systems

초록

This paper presents a high-reliability current source inverter with a switching-cell structure for grid-connected photovoltaic systems. When compared to the conventional current source inverter, the proposed converter has no open-circuit issue, which can minimize the overlap time interval. As a result, the output waveforms quality is considerably improved. In addition, by adding capacitors, the high-frequency loops inside the inverter can be easily reduced to inhibit switching spikes. Commonmode chokes and split capacitors are also employed at the input to solve the leakage current problem of the photovoltaic transformer-less inverter. The operating principle of the inverter is analyzed. A 500 W prototype of a single-phase switchingcell (SC) current source inverter (CSI) was designed and tested to verify the feasibility of the circuit.

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