Performance Analysis of Half-Bridge Commutation Cells of a Modular Multilevel Voltage Source Converter

Abstract

This study presents a performance analysis of a half-bridge commutation cell using MATLAB/Simulink simulations. The behavior of IGBTs as semiconductor switches is examined under diverse load conditions, and the power losses, including conduction and switching losses, of two IGBT models, IXGH25N120 and IRG7IA19UPbF, are evaluated. A simulation-based design methodology is proposed for selecting suitable IGBTs for the half-bridge commutation cell. The comparative analysis reveals that the IXGH25N120 IGBT is well-suited for high-performance applications, while the IRG7IA19UPbF IGBT is optimized for energy recovery circuits. Furthermore, it is observed that IGBT1 (IXGH25N120) exhibits higher power losses due to its significant conduction losses compared to IGBT2 (IRG7IA19UPbF). The IGBT2 exhibits low conduction losses but has dominant switching losses due to high switching frequency. The utilization of a simulation-based approach provides valuable insights into the influence of IGBT characteristics on the responses of the half-bridge commutation cell, enabling an enhanced understanding for the design and performance analysis of the cell within the context of MMC.

Keywords

• half-bridge cell
• MMC
• IGBTs
• conduction losses
• switching losses
• VSC