A Method to Contain the Temperature Rise of a Press-Pack Thyristor during a Short Circuit Protection Operation

A new packaging structure for clamping the temperature of a thyristor die is analysed in this paper. The proposed structure aims to absorb the heat released from the thyristor during a short circuit protection operation, to maintain the temperature within a defined range even when the current through the thyristor is temporarily very high. The defined range is below the maximum tolerable temperature and is controlled by using phase-change material (PCM). This has the potential to reduce both space and cost when compared to traditional packaging structures which utilise heat sinks. In the course of this investigation, a thermal model of a thyristor is used for comparison. COMSOL Multiphysics was used to simulate the thyristor temperature during a fault and the effect that the PCM has on the thyristor temperature. Experiments have been performed to verify the models and validate the feasibility of the proposed concept.