Utility Interactive Photovoltaic System with PWM Current Source Inverter

This paper proposes a single phase utility interactive photovoltaic system using an IGBT current source PWM inverter with the two auxiliary IGBT's. With the two auxiliary IGBT's, a sinusoidal PWM can be performed easily because the waveform of the inverter DC voltage is made up of not only line and zero voltages but also half the line voltage. It has been experimentally verified that sinusoidal output current, power factor near unity and virtual maximum power can be obtained without any feedback control. Stable power condition can be obtained on starting or regardless of isolation change and line voltage transient because the system does not have any feedback control to interconnect with the utility line. The system behavior of malfunction has also been clarified and shown to have high reliability.