A Novel Single-Phase Switched-Capacitor Transformer-less 5-level Inverter Topology with Voltage Boosting

摘要

Common mode voltage (CMV) is a serious problem in case of grid-tied solar PV multilevel inverter with transformerless implementation. Due to CMV there is flow of leakage current which creates issues like grid current distortion, increased losses, safety issues etc. To address this issue, this paper proposes a novel transformerless inverter with voltage boosting capability and 5-level performance. The proposed inverter topology is based on switched capacitor principle which enables extra level generation and voltage boosting. A 4 quadrant switch is connected across the output terminals to achieve ac decoupling feature in the proposed inverter. A novel PWM strategy is proposed to operate the given topology in such a way that CMV is eliminated entirely. A simulation model is developed in PLECS software to study the performance of the proposed system and justify various claims.