Research On Multifunction Protection Module Of Control And Protective Switching Device

With the development of electromechanical integration industry in 1980's, control and protective switching device (CPS) which is a new type integrated apparatus used in low voltage power distribution and control system appeared. This single electromagnetic construction apparatus performs multiple functions of circuit breaker, contactor, thermal relay, starter, isolator, counter, etc. It has many advantages such as small volume, strong functionality, high reliability, control and protection self cooperation and convenient operation. At present, performance of CPS is improved in ways of mechanical structure of electromagnetic and transmission system, breaking capacity of contactor and arc quenching system. But the protective function of CPS needs to further improve. In this paper, the multifunction protection module of CPS is researched for improving performances of protection and control using advanced fault diagnosis and control method.Base on the conventional protection method of electric control system, a new protection method with fault pattern recognition function is expounded in this paper. While the normal protection function is realized, Support Vector Machine (SVM) which is a new kind of novel machine learning methods is used to build fault diagnosis model in order to recognize pattern and location of the fault. Using this protection method, protection module not only realizes the protection function, but also reflects fault more particularly and directly. The protection performance of module is improved.On the basis of the protection method, the design of hardware and software of intelligent protection module is begin. The PIC is the central of the design. First of all, the block diagram of hardware is presented. Hardware designs of data acquisition circuit, output control circuit, keys and display circuit are completed. Then, modular design method is adopted to compile program. Program is divided into several independent subprograms, such as initialization, data acquisition, data processing, fault protection, keys and display, to program and debug. Eventually, the subprograms are combined and the software design is completed. Finally, various faults are simulated to test intelligent protection module. It is prove that the functions of protection and fault pattern recognition of intelligent protection module are achieved well.