Development and implementation of a three-phase TCHB multilevel inverter using NLC technique for PMSM drive applications

• Main Author: Hossain, Md Showkot
• Format: Thesis
• Language: English; English
• Published: 2025
• Subjects: T Technology; TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utem.edu.my/id/eprint/29005/

Multilevel inverters (MLIs) are widely recognized for their ability to improve output waveform quality and enhance system efficiency in high-power applications. However, conventional topologies like the Cascaded H-Bridge (CHB) require numerous switches and isolated DC sources, leading to increased system cost, complexity, and space requirements. This research addresses these limitations by exploring a more compact and efficient alternative; the Transistor Clamped H-Bridge (TCHB) MLI. The TCHB inverter offers a cost-effective solution by achieving multiple voltage levels with fewer components, making it well-suited for modern motor drive systems. This study proposes the development and implementation of a Nearest Level Control (NLC) technique for a three-phase 13-level symmetrical TCHB inverter fed Permanent Magnet Synchronous Motor (PMSM) drive. The 13-level configuration is specifically chosen to balance output quality, control complexity, and hardware feasibility. The core problem addressed is the reduction of Total Harmonic Distortion (THD) without compromising drive performance, particularly in space- and efficiency-constrained environments such as electric vehicles and industrial automation. A Field-Oriented Control (FOC) strategy, integrated with a Proportional-Integral (PI) controller, is applied for precise speed and torque control. The methodology involves both MATLAB/Simulink-based simulation and hardware implementation using dSPACE. NLC is selected for its low switching frequency, simple implementation, and suitability for high-power applications. Key performance indicators, including THD, efficiency, and dynamic response, are thoroughly analyzed. Experimental results validate the effectiveness of the proposed inverter, achieving a THD of 4.2% in compliance with IEEE 519-2014 and closely matching simulation outputs. The system exhibits robust speed tracking and stable stator current under dynamic torque conditions, confirming its reliability across varying loads and operational scenarios. This research demonstrates the potential of integrating NLC with TCHB MLI and FOC to deliver a compact, efficient, and high-performance solution for advanced PMSM drives, with strong relevance to future electric vehicle and industrial drive applications.