Study on the Water Path Design of Power Unit of Press Pack Device Based on Field-Circuit Coupling Approach

Press pack power semiconductor devices are commonly used in the field of high-power power equipment due to their advantages of double-sided heat dissipation, sealing, explosion-proof, etc. However, due to its pressed installation method, it results in a large number of water-cooling heat sinks and water pipes inside the power unit compared to the welded power semiconductor device power unit. The water connection is complex, and the water path design is difficult. This paper takes a cascade type H -bridge converter power unit as an example, introduces a field circuit coupling simulation method to analyze each hydraulic parameter of who water path inside the power unit based on pressed power semiconductor, and introduces the power device arrangement and heat dissipation circuit design. By adding necking, the internal parallel water path is levelled and designed, while the design method of necking parameters is optimised by FEM parameter simulation. Based on the water path design and analysis method, a power unit prototype is designed, and the accuracy of the waterway design and analysis method is verified through the water path test of the prototype.