Generalized Switched-Capacitor-Based Hybrid Multilevel Inverter With Reduced Components Count and Inrush Current

Abstract

This article presents a novel topology for a three-phase switched-capacitor (SC) based hybrid multilevel inverter (HMLI) with boosted output voltage. The proposed topology employs generalised structure of SC-based inverters (SCBIs) to improve the output voltage levels utilising SC cells. The proposed structure additionally features self-charging and voltage-balancing capabilities of the SCs, without the need of auxiliary circuit/sensor. A modified PWM (MPWM) technique is utilized to modulate the system. The MPWM results in improved output voltage profile and reduction in voltage ripple across the SCs. The proposed structure is quantitatively compared with the state-of-the-art topologies to demonstrate its advantages in the terms of reduced components count, low maximum blocking voltage (MBV), low total standing voltage (TSV), lessened total harmonic distortion (THD), lowered cost function (CF) per level, and boosted output voltage. The performance of the proposed topology is verified in MATLAB/Simulink environment and a laboratory prototype is developed to confirm the feasibility to operate at steady-state and dynamic conditions.