Single-phase soft-switched current-source inverter for utility interactive photovoltaic power generation system

A novel single-phase soft-switched current-source inverter, which connects the photovoltaic arrays with the utility grid, is studied. To provide the soft-switching capability under the pulse width modulation for a line-commutated thyristor inverter, an auxiliary resonant switch to bypass the current on the DC side is connected across the DC input of a thyristor inverter. The arrangement tested, using two insulated-gate bipolar transistors and a single-phase thyristor bridge, is implemented to investigate the operation under the sinusoidal pulse width modulation. The operation is also simulated using PSpice. The experimental and simulated results confirm that the utility current can be sinusoidally waveshaped with a near unity power factor.