Fault Diagnosis Method Research Of The Intelligent Substation Considering The Secondary System

Recently, with the development of our country’s strong smart grid, the development of the intelligent substation has entered into a rapid stage. Specifications of design for 110 (66) kV-220kV intelligent Substation which the State Grid Corporation posted in 2010 stipulated that "the intelligent substation should have the ability of intelligent alarm and fault information comprehensive analysis, and automatic report of abnormal substation and put forward the guidance of fault treatment." And this means that the fault diagnosis plays a very important role in automation operation of the intelligent substation, and it is a very important research direction of the intelligent substation.The traditional substation fault diagnosis is based on the action information of the protection and circuit breaker and the fault recording information, which uses the mathematical analysis and optimization algorithm and artificial intelligent methods to realize the fault location of the primary system. Compared to the traditional substation, the intelligent substation has changed a lot, and those mainly manifested in the intelligent primary system and the networked secondary system, which means that the traditional fault diagnosis method is not applicable in the intelligent substation. However, the networked secondary system improves the controllability and observability of the intelligent substation greatly, and meanwhile the abundant alarm information of the secondary system provides strong support of the intelligent substation fault diagnosis. And according to this, this paper provides a new method of the intelligent substation, which can realize the comprehensive diagnosis of the substation, and the main work is as follows:(1) This paper provides the basic framework of intelligent substation fault diagnosis. The basic framework consists of two parts:the fault information source model and the fault diagnosis process. The fault information source model is as the data input part, which mainly contains the alarm information of the primary and the secondary system. On this basis, this paper uses the intelligent algorithm to realize the accurate fault location, and at the same time, this paper analysis the abnormal action of the protection and circuit breaker.(2) According to the situation of intelligent substation, this paper provides the fault expression model-it is the fault -alarm directed bipartite graph model. And this model expresses the constraint relation between fault components and alarm information simply, and uses the incidence matrix to express the constraint relation.(3) Based on the fault -alarm directed bipartite graph model, this paper provides the intelligent reasoning model for the intelligent substation fault diagnosis. And bases on the information source of the primary and secondary system, this paper uses the ratio form Bayesian algorithm to realize the fault probability calculation of the suspicious fault elements. And meanwhile, this paper uses the information fusion method to realize the accurate fault location.(4) According to the action of protection and circuit breaker, this paper provides abnormal analysis model of the protection and circuit breaker. Firstly, classification of protection and circuit breaker tripping and malfunction, and secondly, reasoning the abnormal protection and circuit breaker layer by layer. And finally, this paper forms the complete intelligent substation fault diagnosis report.