PWM sensor-less balancing technique for the three-phase seven level PUC-NPC converter

Abstract

Abstract This paper presents an innovative PWM technique for a three-phase seven-level PUC-NPC converter that achieves automatic capacitor voltage balancing without complex control systems or additional sensors, addressing a key challenge in multilevel inverters. Unlike conventional designs requiring costly closed-loop control, the proposed hybrid PUC7-NPC topology generates five-level output using a single DC source while leveraging inherent redundant switching states for natural voltage regulation. The method simultaneously minimizes total harmonic distortion (THD) through optimized switching patterns, ensuring compliance with power quality standards. MATLAB/Simulink simulations confirm the converter’s stable performance across various switching frequencies, demonstrating its suitability for diverse applications including motor drives and grid-tied solar systems. The proposed solution represents a cost-effective, high-performance alternative for modern power conversion systems, offering simplified implementation without compromising output waveform quality.