Application And Research Of Fault Monitoring And Diagnosing Technology In Substation SCADA System

SCADA(Supervisory Control and Data Acquisition) system has been widely used in industrial areas. This paper focuses on digital substation system in power grids.Digital substation system which based on Ethernet and Fieldbus can be divided into four levels and thus it produces complex fault messages. With the extended scale of the system, more and more fault messages flood into monitoring station so that monitors cannot judge and deal with them instantly; at the same time, since complex fault messages can be produced in every level, false positive and false negative are inevitable, which will cause serious economic losses and even damage life safety. Therefore, the development of an excellent fault monitoring and diagnosing system is urgent.Firstly, this paper analyses system fault deeply to find methods of monitoring and diagnosing, adopting fault tree to clarify four sources of fault:parametres of power grids, hardware devices, communication channel, and drivers programme, together with their bottom reasons and explanation. Fault tree can be displayed by tree graph, analysed qualitatively and quantitatively, and combined with expert diagnosing system. This paper decides a combination of interrupting and polling communication mode and an expert diagnosing system method based on fault-tree rules.Fault monitoring includes online and offline monitoring, what’s more, monitoring includes detecting and displaying. Detecting programme acquires fault information and writes them into fault database. This paper adopts BST(Binary Search Tree) as real-time database and serialized documents as history database, and designs interfaces to encapsulate query, insert and delete operations. Displaying technology includes scripts, lists, and history trend curve, accomplishing fast fault locating and system fault forecasting.Fault diagnoses adopts expert methods, transforming fault-tree structure into expert knowledge table, relationship between sub-trees into expert reasoning mechanism, and explanations of bottom events into explaining mechanism. Users can diagnose and explain fault quickly and accurately when implementing fault diagnosing system. In addition, in order to extent the uses of developed system, this paper designs a remote module based on C/S model and shared memory technology, accomplishing safe remote monitoring and diagnosing.In the process of development, VS 2013 is the main tool to develop software. This paper uses COM, multithreading, and sockets software technology to develop and test the whole system in the environment of Windows 7, providing interfaces of functional module for further development.This paper tests the whole system thoroughly using Jinan Luokou clothing market project. It proves that the developed system is reliable, real-time, and feasible. Lastly, making a conclusion on limits of the system and prospecting trends of progress in the future.