Quasi-Resonant Switched-Capacitor-Based Seven-Level Inverter With Reduced Capacitor Spike Current

Abstract

This article proposes a novel seven-level multilevel inverter (MLI) with integrated output voltage boosting functions. The inverter uses switched capacitors (SCs), a key component of a voltage-boosting approach, to achieve the goal of increasing the output voltage at the load end. Additionally, the MLI has the ability to automatically balance the capacitor voltages. The proposed inverter is more cost-effective and has lower conduction losses than those of its rivals since it has fewer components than competing designs. An inductor is used in the capacitor charging loop to both minimize dc source current spikes and enable quicker charging of the capacitor, thereby increasing the capacitor’s lifespan. This article provides a number of waveforms, including output voltage and current, under various loading conditions and modulation indices. A laboratory model is also employed to support the viability of the proposed topology. The performance of the system is verified using MATLAB/Simulink. At long last, the maximum achievable experimental efficiency of 98.77% and total harmonic distortion (THD) for output voltage and current were 20.44% and 0.54%, respectively, at 300 V and 1.2 kW load.