Structure design and analysis of high voltage IGBTs series connection experimental platform

Insulated Gate Bipolar Transistor (IGBT) has the advantages of high rated voltage, high rated current, high switching speed and easy to drive. But a single IGBT still cannot meet the needs of the high-voltage converters at present. IGBT series and parallel connection can greatly extend the application of IGBT because it can effectively improve the system voltage and current capacity. Generally, the volume of high voltage IGBTs series connection converter is large because of the insulation and thermal performance requirements. It means that the bus bar structure is complex, and the stray parameters of the commutating loops, especially the stray inductance, will significantly influence the switching processes. It becomes one of the key points for the safe operation of the converter. In this paper, the design principles for complex physical bus bar are presented. Based on the finite element analyses, the bus bar structure of a high voltage IGBTs series connection experimental platform is designed and improved. The performance of the improved bus bar structure is verified by simulations and experiments.