Research On DC Solid-State Power Controller

Solid-State Power Controller is a kind of intelligent switches, which incorporates the wire protection function of circuit breaker and the reliability of solid-state relay. Using Power MOSFET as switch, the power controller has the features of high-speed of on-off, no contact, no arc, less electromagnetic interference, high reliability and easy to be controlled by microcomputer.Firstly, taking 28V DC SSPC as an example, this paper presents the design of DC programmable SSPC and correlative technologies, such as control time sequence, programmable protecting technology, short-circuit protection and so on. The design of 270V DC SSPC is also introduced in this paper. The correctness and feasibility of these design and technologies are proved by the test of the prototype.Secondly, the component-counted reliability estimated method is used to estimate the reliability of the designed 28V and 270V SSPC prototypes. Through the estimate, the prototype's failure rate and the mean time between failures (MTBF) are obtained. And the qualitative analysis is carried on with the FTA method. Then, the main factors causing short interference are discussed and analyzed in the paper. From the results, some methods of the anti-jamming are brought forward to improve the circuit. The reliability of the system is enhanced.Finally, a model of SSPC is set up in Saber. The working states of the power distribution nets using SSPCs as switches are emulated. Through the emulational results, some deficiencies which have not been concerned in the design of the prototype are emerged. Moreover, some meliorative suggestions of the design and some requirements of using SSPC in the power distribution net are put forward. All of these are useful to the improvement and practicability of SSPC.