Study of Parallel Technique for IGBT MMC Modules

IGBT parallel connection is a practical solution to increase the current capacity of power electronic equipment, the current sharing of IGBT parallel modules is an application difficulty. The factors that affect the parallel current sharing of IGBT mainly include the IGBT’s own characteristics, the IGBT gate driving strategy and the peripheral main circuit. The stray inductance and mutual inductance parameters of the busbar are extraced using Q3D software, and it calculated the stray inductance value of each part, indicating that the mutual inductance parameters of the busbar have a significant impact on parallel current sharing. It proposed a design scheme to increase the distance between busbars to improve the current sharing. By developing a 0.9kV/30kW VSC-HVDC (MMC) full bridge module and building a platform for testing, the experimental results verified the effectiveness of the design.