Research on parallel current sharing Technology of Silicon Carbide MOSFET

Abstract

With the continuous development of semiconductor technology, the performance of silicon-based power devices has reached its limit, and the new wide band semiconductor power devices represented by SiC MOSFETs play an important role in various fields such as rail transportation, aerospace, induction heating, and new energy vehicle. The current capacity of individual SiC MOSFETs is not large, so in order to meet the demand of high-power power electronics devices, SiC MOSFETs need to be connected in parallel to increase the system through-current capability. However, due to stray inductance, variation of device characteristics, and asymmetry of PCB layout, parallel switching devices will have unbalanced currents, which may cause damage to the system. To solve this problem, this paper uses Multisim software build a simulation circuit, measure the current between two parallel SiC MOSFETs, analyze the specific causes of the unbalanced current, and propose a parallel current equalization method for SiC MOSFETs using a gate series current equalization resistor combined with a coupling inductor, and finally verify the feasibility of this method by simulation and experiment.