Small Scale Utility-Connected Solar Photovoltaic Power Conditioner using Soft Switching High-Frequency Sinewave Modulated Inverter Link for Residential Applications

The utility-interfaced sinewave modulated inverter for the solar photovoltaic power conversion conditioning and processing with a high frequency transformer isolated AC link is presented for residential applications. As compared with the conventional full-bridge hard switching-based PWM inverter with a high frequency AC link, the simplest single-ended quasi-resonant soft switching-based sinewave modulated inverter with a duty cycle pulse frequency control is implemented, resulting in size and weight reduction and low-cost. This paper presents a prototype circuit of the single-ended zero voltage soft switching inverter-based sinewave power processor for solar power conditioner in addition to its operating principle. This paper also proposes a control system to deliver high quality output current. The power loss evaluation under actual power processing is discussed from an experimental point of view. A newly-developed sinewave power processor which has 92.5% efficiency at 4kW output is demonstrated for small scale utility-connected power aplications.

Zero voltage soft switching

High frequency inverter

High frequency transformer link

Utility interfaced solar power conditioner