Weighted-Efficiency Enhancement Control for a Photovoltaic AC Module Interleaved Flyback Inverter Using a Synchronous Rectifier

In this paper, a weighted-efficiency enhancement control method for an interleaved flyback inverter using a synchronous rectifier is proposed based on photovoltaic ac modules. In this control method, the operation of the synchronous rectifier is classified according to the voltage spike across the main switch. When the voltage spike across main switch is lower than the rating voltage of main switch, the operation of the active clamp circuit is interrupted to reduce the switching loss of the auxiliary switch. At this time, the synchronous rectifier is operated for the zero-voltage switching of main switch. When the voltage spike across main switch is higher than the rating voltage of main switch, the active circuit is activated to reduce the voltage spike. The synchronous rectifier is operated to reduce the conduction loss of the secondary output diode. Thus, the switching loss of the main switch can be reduced in the low power region, and the weighted efficiency can be improved. A theoretical analysis and the design principles of the proposed method are provided. The method is validated through simulation and experimental results.