High-voltage IGBTs series converter bus bar design and stray parameter analysis

High-voltage IGBTs series are one of the most effective means to improve converter voltage levels and capacities.However,the complex mechanical structure when the devices are used in series complicates bus bar design and stray parameter modeling.The results may not be accurate if the conventional PEEC method is used.This paper describes the bus bar design principles and ways to improve the PEEC method when extracting large complex structure bus bar stray parameters.The bus bar parameter model is based on the partitioning calculation result.The influence of stray parameters during the switch transient process is illustrated by simulations and tests on a 4.5kV/600AHVIGBTs series experimental platform with consideration of the diode forward recovery characteristics.The results illustrate the accuracy and practicality of the method and how bus bar design effectively reduces the stray parameters and creates favorable conditions for active control.