A Power Decoupling Solution for Improved Y-Source Single-Phase Grid-Connected Inverter

This article proposes a power decoupling solution based on improved Y-source single-phase inverter with no additional power semiconductors for PV systems. Single-phase inverter would cause voltage and current ripples on DC link because of double-frequency power ripple. On the other hand, the improved Y-source inverter has a continuous input current and a high voltage gain using a small shoot-through duty ratio. As a result, the improved Y-source inverter is utilized for power decoupling instead, with only two capacitors added between the midpoint and each inverter arm. A corresponding control method is proposed to ensure the power ripple absorbed by the two decoupling capacitors without affecting the grid current. Finally, a 200W laboratory prototype is built based on a TMS320F2812 digital signal processor to verify the performance of the proposed power decoupling solution.