A Novel Current Limiting Protection Control Strategy by Power MOSFET Thermal Management for Solid-State Power Controller

This paper combines real-time temperature detection of MOSFETs inside solid-state switches with a temperature field model, and proposes a current limiting protection control strategy based on real-time heat management of MOSFETs. This strategy can avoid the unreasonable setting of current limiting protection time in solid-state switches during short circuit faults, leading to overheating and failure of MOSFET, and thus causing faults in HVDC power distribution system. Firstly, we analyzed the protection characteristics and shortcomings of solid-state switches such as solid-state power controller(SSPC) and solid-state circuit breakers (SSCB). Secondly, we optimized the circuit design of the solid-state power controller and the conversion relationship under different operating conditions, and elaborate on the implementation method of this control strategy in detail. Thirdly, we established a heat dissipation model for the MOSFET of SSPC, conduct theoretical and simulation analysis, and obtain the temperature field distribution of the MOSFET; Finally, the temperature of the MOSFET core is calculated by collecting the temperature of the position through the solid-state power controller temperature sensor, achieving accurate measurement. This paper also developed a prototype of a solid-state power controller with a rated current of 20A at 270V DC, and conducted short-circuit current limiting protection tests at 5 times the rated current; Experiments have shown that this control strategy can effectively prevent the overheating failure of the MOSFET.