The Research Of An Expert System For Substation Switching Sequence Based On The Object-oriented Method

Switching sequence system is an important measure by which the management department of power system maintains the economical and safe work of power system. With the development of power system and the complexity of the electrical network, the work for editing switching sequence rapidly and rightly is faced with the tremendous challenge. Obviously, traditional means for editing switching sequence can not meet the requirement of power system in the new situation. In the case, a new intelligent switching sequence expert system will replace it and become an important auxiliary tool for the dispatch of power system.Based on the analysis of the existed switching sequence expert system, a new switching sequence expert system is developed by the Object-Oriented programming and the theory of the expert system. In the system, Relation database model is adopted to memory the parameter information of the device, and the adjacent matrix is used to memory the network topology of power system. Database can receive the real-time data from SCADA system, then send it to the main connection drawing. Based on the Object-Oriented technology, different devices are categorized to different device classes in which properties and member functions are encapsulated. Device class is derived from element class and device sub-class is derived from device class. Based on the construction of the device class model, main connection drawing of substation and the inference engine of the switching sequence are realized by VC++ 6.0 development tool. Main connection drawing is cable of communicating with the drawing database each other. A kind means of knowledge representation combining the produce style representation and the Object-Oriented representation is proposed in the paper, which promotes the efficiency of rule search and reduce the workload of the maintenance. In the realization of the inference engine, the forward inference control strategy and the deep-prior search strategy are preferred. Three kind of means for making switching sequence can be selected, which are graphic make, representative make, intelligent make. Some other auxiliary functions are provided in the system, such as the maintenance of the database and knowledge base.