Active thermal cycle reduction of power modules via gate resistance manipulation

This paper discusses active thermal cycle reduction techniques for power electronic modules. These reduce the thermomechanical strain in the interconnects of the power module leading to an enhanced reliability and lifetime. For this purpose, a model based control algorithm is presented, which allows controlling the temperature of the devices within one half bridge. It uniquely uses a virtual heat sink to determine feasible trajectories for active thermal cycle reduction. This concept is the first to explicitly handle the limitations of the loss manipulation process for a multi-device module. Loss manipulation is realized least invasively by online manipulation of the gate resistance only. For temperature estimation with zero lag, a spatial observer structure is used. It demonstrates the feasibility of observer based active thermal control. The complete control algorithm is validated experimentally with a three phase power module on a load emulator using realistic load cycles.