Research On Expert System Of Graphics Aided Switch Sequence Based On Object-oriented

Power industry is the basic industry of civil economy, and is the one of economic base of the country. Its secure work is rather important to the development of civil, economy. In the running process of power system, it needs do many switching operations for devices examined and the running way changed. Error operations brought by switching operations done frequently will result in larger percent accidents, this will threaten the power system run greatly. Switch sequence system is an important measure for power management department to avoid the error operations and secure power grid run safely. With the development of power system and the complexity of power grid structure, it is very difficult to write switch sequence correctly and quickly. Obviously, traditional writing way has not been met to the development needs of power, system in this situation. So a new switch sequence system is needed as the aided tool for operators to progress power grid dispatched.According to the analysis of the existed switch sequence expert system, the expert system of graphics aided switch sequence based on object-oriented is presented with the object-oriented programming and the theory of the expert system and computer graphics, the database of Microsoft SQL Server 2000 and the tool of Delphi6.0. The distinguishing features of the system are as followings:1. A new knowledge representation combining the produce style representation and the Object-Oriented representation is proposed in the paper, which facilitates modification and expansion of knowledge rules and reduces the workload of the maintenance. Forward inference control strategy and the deep-prior search strategy are used to realize the inference engine, which improves the efficiency of the inference engine largely.2. The graphic class of devices is designed by the object-oriented technology and factory method, which improves the reuse and maintenance of codes. On the basis of the constructed model of graphic class, many functions of graphics are achieved by the aid of some algorithms of computer graphics, such as: selection, deletion, movement and so on.3. The concept of integration of graph-based database is used in this system, the relation database model is adopted to memory the parameter information of graphics, the drawing module of the main wiring diagram has the accessing function with the drawing database each other, and the database can receive the real-time data from SCAD A system.4. Different users have different accessing permission in the system, in order to control the allowable operations of different users and confine the accessible files and data. Setting up this clear duty, this provides effective protection for the system and promotes management work to be standardization.5. Three-layer network structure is adopted in the system, and it will enhance the efficiency of server and the security of system.6. In addition, some other accessorial functions are provided in the system, such as the inquiring and counting switch sequence, the demonstration and train of the system, and so on.