Thermal Model for Pulse Power Switch Centered on Thyristor Device

The working current of the thyristor as the pulse power switching device is often several times of the average current of thyristor.The power loss can produce lots of heat for its junction at the short time,and the junction temperature will rise instantly and obviously,which will breakdown its junction region or damage the device.Therefore,it is important to optimize the cooling structure of the power pulse switch with good cooling capacity.A thermal model based on the thermal Cauer model of the 5STP 52U5200device produced by ABB is introduced by the paper.Thermal network model of the pulse power switch is established and simulated centered on the SimuLink environment of Matlab.The relationship curves of the power loss vs.the highest junction temperature and the power loss vs.the case temperature are acquired.The thermal resistance and heat capacity of the conductive plates have an effect on the junction and the case temperature of the thyristor. Both theoretic analysis and experimental results can verify the truth of the design method of the cooling structure of the pulse power switch centered on the thyristor device.