Impact of flyback transformer and switch parameters on efficiency of single stage photovoltaic microinverter

Abstract

The single stage photovoltaic microinverter with the new topology based on the couple of two-switch DC-DC flyback converters has been investigated. The microinverter is characterized by the high efficiency and simple design. The impact of flyback transformer parameters and impact of parameters of switch transistors on the microinverter efficiency have been investigated. The results were obtained for the cases when CL and LCL output low pass filters were used. The investigation results show that the efficiency of microinverter can reach 98% at 50 W and 96% at 150 W output power if the parameters of flyback transformer and MOSFET transistors of switches are chosen properly. The obtained results show that the efficiency of the investigated photovoltaic microinverter based on the LCL output low pass filter is higher as compared to the case when the LC output low pass filter is used. The efficiency of microinverter with the LCL output low pass filter remains practically constant and does not decrease up to 70 W output power. However, in the case when CL output low pass filter is employed the efficiency decreases with the power even at low power values.