Utility interactive inverter with high-frequency link for photovoltaic power system

We have developed a utility interactive inverter for the photovoltaic power generation system. Since we have adopted a high-frequency transformer-link method to main circuit and have reduced magnetic component size and weight, the inverter realizes the weight of 17 kg and the capacity of 0.02 m(3). The conversion efficiency of the inverter at rated output is 91.8% and that at a quarter output is 91.0%. We have developed a digital control technology using a digital signal processor (DSP) at the control circuit. The total output current harmonic distortion factor of less than 1.0% is achieved by the development of current feed-back control technology based on it. New maximum power point tracking control technology improves the tracking precision within 15 W. Also, we have developed new technology for the prevention of isolated operation which can certainly detect the fault.