A New Five-Level Switched-Capacitor-Based Transformer-less Common-Grounded Grid-Tied Inverter

Abstract

This paper proposes a new switched-capacitor grid-tied inverter. The proposed topology can eliminate leakage current using a common-grounded strategy. Also, the proposed topology generates a five-level output voltage waveform using a single input dc source with a voltage boosting factor of 2. This structure uses six power switches, two diodes, and two self-balanced capacitors. The proposed inverter has some advantages such as a common-grounded feature, eliminated leakage current, and voltage boosting feature with single-stage energy conversion operation. Also, the proposed topology can support both active and reactive powers and generate a perfect sinusoidal output current injected into the grid. Also, to control both active and reactive powers an efficient control strategy is applied. To generate the precise gate pulses for the power switches, the introduced efficient control strategy is applied. Also, comprehensive discussions on the operating modes of the proposed inverter, Capacitor charging current analysis, the control technique, and design considerations are presented. To show the advantages and differences of the proposed inverter with some other recently presented switched-capacitor-based grid-tied inverters a comparison study is considered. Finally, to validate the performance and feasibility of the proposed inverter, various experimental results based on a 620 W experimental prototype are presented.