Research on Grid Connected Inverter Based on Parallel Resonance

In order to solve the problem of large switching loss, large voltage peak and poor stability in DC-DC transform high frequency isolation inverter, a new inverter circuit topology, which is combined with parallel resonant and traditional DC-DC converter, is proposed. The inverter can realize the zero voltage opening of the high frequency power device, the soft turn off of the body diode and the rectifier diode, so as to eliminate the switch peak of the power device and reduce the loss of the inverter. The working process of the circuit and the soft switching principle of various switch devices are introduced in detail, and the resonant equivalent model of the circuit, the influence of the resonance parameters on the gain and the soft switch are established, and the design principle of the resonant parameters is given. In order to eliminate the low harmonics introduced by dead zone, dead time compensation is added to the control system to improve the quality of inverter current. Finally, an experimental prototype is built, and the correctness of the circuit topology and control strategy is verified by experiments.