Phase-controlled Switching Technology Realization Of Vacuum Breaker Faced On Short-circuit

Vacuum circuit breaker as a part of the smart grid, it is a research focus. It can achieveintelligent operation, could be real-time and accurate judgment circuit conditions andrequirements, and make the corresponding action. At this stage of the latest research isphase switch technology. The technique used digital signal processor intelligent to controlunit to control points or perform the phase. Phase selection control technology has theadvantage that it could increase the breaking capacity of vacuum circuit breaker, theguarantee of power supply quality, also extend the life of the switch. At present, the faultcurrent phase breaking technology is not mature, many problems remain to be solved. Thisarticle was from the perspective of single phase short circuit fault in power system,discussed about the vacuum circuit breaker in the circuit fault after fault judgment, andfunctions of open circuit fault phase selection method.First of all, short circuit fault occurs to the fault current was selected and inenitialfailure moment was determed. In this paper, MATLAB SIMULINK toolbox was used tobuild models of power system fault. The sum of two phase current was used to determinethe fault phases, then wavelet analysis was used to sample fault current. From the results ofwavelet toolbox of MATLAB, the moment of short circuit occurred was determined,provided a basis for prediction of fault current parameters behind.According to single-phase power system short circuit model, the expression of aftershort circuit fault was determined. LMS was used to simplify and improve Fault currentmathematical model, so the error of fault current of the prediction wsa smaller. The burningenergy of electric arc was researched. The corresponding parameters was set, many timessimulation was done to verify this algorithm, proved the feasibility of the LMS. Aftercorresponding parameters to calculate the fault current, it could be concluded that the waittime after relay protection action. Finally, designed intelligent control unit based on DSPwas used to sampling and control of the whole process of open circuit, made the wholeprocess of phased open circuit more accurate quickly.