Protective Relay Intelligent Setting Based On The Decision Of Operating Mode And The Reformative Expert System

The relay protection ensures the safe operation of the electric system .The relay setting must be selected reasonably in order to exert effect of the relay protection completely. So the setting work which is done well is the key in electric safe operation.The software of relay setting calculation can increase the efficiency and decrease the workload greatly. According to the characteristic of the local electric net, this paper connects expert system with Microsoft VC++ by using OOP technique. And it designs the rule-base which is classed and graded. It achieves intelligent setting of the protection based on the reformative expert system.By introducing membership grade in fuzzy-math in the design of rule-base, this system solves the problem that when it is sensitivity ,the setting may be unreasonable. So the software possesses the practicality and the currency.The process of the setting needs to decide reasonable power system's operating mode .The traditional ways always consider seldom mode, which makes the setting too conservative. Considering all operating mode is difficult This paper, based on the traditional ways, proposes a new method in choosing operating mode, aided by establishing couple degree. This method reduces the choosing number of operating mode. And it is fast by using computer. The new method is proved in the example.