Enhancing Energy Efficiency in Electric Vehicles Using a Novel DC-Link Voltage Balancing Technique for Three-Level H-Bridge Inverters

Abstract

This paper presents a novel DC-link voltage balancing technique designed to enhance energy efficiency in electric vehicles (EVs) utilizing three-level H-bridge inverters. The study compares two inverter topologies—an 8-switch active neutral-point-clamped (ANPC) configuration and a 6-switch diode-clamped variant—highlighting their respective capabilities and limitations in maintaining capacitor voltage symmetry. The proposed control algorithm dynamically adjusts switching patterns based on real-time feedback from capacitor voltages and load current direction, ensuring balanced operation under varying conditions such as acceleration, deceleration, and regenerative braking.

Simulation results using MATLAB/Simulink demonstrate that the 8-switch topology achieves superior voltage stability and lower total harmonic distortion (THD) compared to the 6-switch configuration. Experimental validation on a DSP TMS320F28379D-based platform confirms these findings, showing a reduction in THD from 5.32% to 4.01% and a capacitor voltage imbalance minimized to within ±1V. These improvements contribute to higher power quality, reduced thermal stress, and enhanced inverter reliability.

By integrating this balancing strategy into EV powertrains, the proposed method offers a practical and scalable solution for next-generation electric vehicles requiring compact, efficient, and robust inverter control. Future work will explore extending this approach to multi-phase systems and evaluating its performance under diverse driving cycles and environmental conditions.