Dynamic characterization of parallel-connected high-power IGBT modules

In high power converter design, IGBT modules are often operated in parallel to reach high output currents. Evaluating the electrical and thermal behaviour of the paralleling IGBTs is crucial for the design and reliable operation of converter systems. This paper investigates the static and dynamic characterization of paralleling IGBTs and the influence of the electrical parameters on the IGBT behaviour. Si based IGBT power modules with voltage rating of 4.5kV and current rating of 1 kA are used for the experimental evaluation of module parallel connections. Parallel connected modules have been driven by several commercial IGBT gate units at various DC-link voltages and current levels and with different temperatures. The tested IGBT gate units show good current sharing performance between the two parallel modules. Other important influencing factors such as busbar design layout, stray inductance variation and gate driving are also investigated for parallel connections of IGBT modules. Finally, the switching energy of the paralleling modules is extracted for IGBTs and diodes under different conditions.