With the continuous increase in equipment power consumption, medium-voltage converters have been receiving significant attention in the industrial sector. However, the limited voltage withstand capability of individual devices restricts the high-power operation of converters, severely impacting the development of modern industries. This article analyzes the IGBT model and investigates the impact of different device parameters on IGBT series-connected voltage imbalance. It proposes measures to suppress voltage imbalance and validates them through experimental testing under the conditions of 1000V and 300A.