A High Gain Common Ground Inverter without Electrolytic Capacitors

For photovoltaic inverters, a voltage gain of more than 10 times, low leakage current, and low input current ripple are three important requirements. However, these functions cannot be met simultaneously by existing inverter solutions. In this paper, a high-gain common-ground inverter is proposed, which structurally eliminates leakage current. A current feedforward scheme is adopted to extract the second harmonic of the DC current, which is then injected into the duty cycle to suppress the DC current ripple. The pulsating power is stored in the intermediate capacitor, thereby eliminating the electrolytic capacitor. Simulation results show that the gain of the converter can reach up to 15.55, and the ripple of the input current is less than 10%.