A Phase-shifted Controlled Full-bridge ZVS SPWM Photovoltaic Inverter With Voltage-doubling Rectifier

Stand-alone photovoltaic (PV) systems are the main application of domestic photovoltaic power generation, and the real PV grid-connected system is still far from us. Generally speaking, the stand-alone PV power generation needs batteries as power storage equipment. 48V DC of the batteries is converted to 220V AC,which usually requires much high step-up ratio. And there is another problem in traditional stand-alone PV power generation system that is low efficient. A phase-shifted controlled full-bridge zero-voltage-switching (PS-FB-ZVS) SPWM photovoltaic (PV) inverter with voltage-doubling rectifier, having high step-up ratio and efficiency, is proposed in this paper.The voltage-doubling circuit, due to its ability to rectify and boost voltage of secondary side of the high-frequency transformer, can improve the step-up ratio of the whole system. With the use of UC3879 controlling phase-shift, the anti-diodes of the switches can realize ZVS, which reduce switch losses and improve the efficiency of the whole system.On the basis of describing and analyzing the existing problems of the traditional PV generation power system, the operation principle and mode of the circuit topology are discussed. In the meanwhile, the control arithmetic is researched. The simulation software Saber is applied to simulate the circuit topology, and the result accords with the theoretic analysis, which confirms that the designed main circuit and control arithmetic are effective and feasible. A hardware circuit is built based on the simulation, and the MCU P87LPC768 of the Philips company is used as the control chip of this system. And then the software program is compiled, which helps to experiment with the hardware circuit.The experimental result testifies that the designed PS-FB-ZVS SPWM photovoltaic (PV) inverter with voltage-doubling rectifier has good performance, and relative waveform and efficiency curve in different load is obtained. At last, the paper summarize the result, and draw a blueprint of the inverter’s future.