Effects of uneven temperature of IGBT and diode on switching characteristics of bridge legs in MW-level power converters

This paper proposes an independent temperature test method for switching characteristic evaluation of high-power single switch modules. For high-power bridge legs, the commutation occurs between two discrete IGBT modules. To simulate the junction differences between two modules caused by mission profile, the junction temperatures of inspected IGBT and related commutation diode are controlled independently using off-line test platform. In consideration of the structural layout, parasitic parameter effects and independent junction temperature control, a high-power switching characteristics platform was built. High power compact IGBT modules with 1.7kV rating and 3.6kA current rating are used for the experimental evaluation and platform feasibility. The quantitative analyses of uneven temperature effects on the switching characteristics are investigated and experimentally validated.