Design and Hardware Implementation of a H-Bridge Sub-module for Single-Phase 5-Level Cascaded Voltage Source Inverters

This paper presents the design and the hardware implementation of an IGBT-based H-bridge sub-module for cascaded voltage source inverters (VSIs). The design methodology and the utilized techniques for reducing stray inductances on the printed circuit board are explained. In addition, the way to calculate and to select the electronic devices are exposed, with special emphasis on the IGBT and its driver. For the design of the circuit board, local regulations for grid interconnection and international standards have been considered to obtain a safe and reliable electronic power cell. The developed hardware has been subjected to different tests by using a single-phase AC electric motor as loads. Two VSIs topologies are evaluated: single-phase 2-level H-bridge inverter and the single phase 5-level cascaded inverter. Experimental tests validate the design and the manufactured hardware and demonstrate an excellent performance, reliability, and high efficiency.