Research On Single-Stage Inverter With Flyback Converter

With the development of renewable energy such as solar energy is more and more, isolation type inverter is attracted the attention of researchers, while the development of inverters tends to high frequency, module integration and digitization. Therefore, research on high frequency isolation type inverter has a certain practical value. This paper firstly studies the high-frequency isolated type single-stage inverter with flyback converter. The features of this inverter have simple circuit, low cost, electrical isolation between input and output, few power stages, easy to control and so on. This inverter is suitable for small power application.In this paper, for the high-frequency isolated type single-stage inverter with flyback converter, the preceding stage is flyback converter with an active clamp circuit, the back stage is full-bridge inverter which is switched as industry frequency. The output of preceding stage is half-sinusoidal wave. The sine wave output of back stage can be acquired by full-bridge circuit which is switched as industry frequency. Flyback converter introduces an active clamp circuit to inhibit the voltage spikes due to the leakage inductance of the transformer, minimize switch voltage stress, and realize the soft switch. This paper analyzes the control strategy of this inverter. On the assumption that the back stage is Ideal switched as industry frequency, the back stage and resistance load can be equal to an equivalent resistance load. Then the control block diagram of voltage control can be established to analyze the control strategy of system. Simulation and experimental results verify the feasibility and validity of this inverter.This paper also analyzes the operational principle and control strategy of the off-grid inverter with interleaved flyback converter. Because of using interleaving technique, this inverter can reduce the current ripple of the power supply side and the output side of the interleaved flyback converter, and improve the output power. The simulation results verify the feasibility of this inverter.This paper studies the application of the inverter with interleaved flyback converter in PV grid-connected system. This paper analyzes the control strategy of this inverter, which introduces digital control chip to realize grid-connected current control and MPPT control. According to "Grid-Connected Solar Micro Inverter" of Microchip Inc, the experimental platform is established. The hardware circuit and digital software flow are analyzed. Simulation and experimental results verify the feasibility of this photovoltaic grid-connected inverter.