Development And Application Of Medium Voltage Test Platform For SiC MOSFET Power Module

Wide bandgap silicon carbide power devices(SiC)have great application prospects in the field of new energy power generation due to their excellent characteristics such as high frequency,high temperature and high power density.It provides a new development opportunity for the high efficiency,high power density and high reliable operation of new energy systems.The dynamic characteristic test of SiC MOSFET provides a sound basis for device selection,drive circuit design,electrical stress assessment and loss prediction of converter.The establishment of loss model and the design of heat dissipation system of converter lay a foundation for long-term and reliable operation of converter.Aiming at the design requirement of SiC MOSFET medium voltage module,a medium voltage test platform for SiC MOSFET is designed,the dynamic characteristics of SiC MOSFET are tested,and a loss model is established in this paper.Based on the loss model,a cooling system is designed and optimized at last.In the dynamic characteristic test of SiC MOSFET,a 10 kV high capacity SiC MOSFET dynamic characteristic test platform is designed in this paper,aiming at the high voltage and high power test requirement of SiC medium voltage module.The test platform is compatible with single-device and multi-device series test,and has the full automatic traversal test function of wide range voltage and current level.The software system takes Lab VIEW and Matlab as the control core,adopts event trigger-finite state mechanism to form a producer-consumer double-layer structure to control and protect the hardware platform in real time.SiC MOSFET modules are tested under complex operation conditions in a remote distance automatically and test data can be aquired and calculated after that.Based on the experimental platform,the relationship between SiC dynamic characteristic parameters and operating environment parameters is tested comprehensively,and the changing trend is analyzed by using SiC MOSFET dynamic characteristic theory.In the aspect of loss modeling and heatsink design,a loss calculation model of SiC MOSFET medium-voltage module is analysed and established for wind power integration of SiC MOSFET medium-voltage module in this paper based on the experimental data of SiC medium-voltage test platform.Based on the calculation results of loss model,the physical structure and spatial layout of heatsinks of SiC medium-voltage module are designed and optimized.The thermal stress distribution under working conditions is determined by FEA thermal simulation,and results are verified by experiments finally.