Study Of Fault Location And Communication Protocol Of Electric Power Network Protective Relaying And Fault Information Process Master System

In recent several years, Electric Power System Protective relaying and fault Information Process System has been attracting more and more attentions. This system is composed of three parts: substation system, communication network and master system. When faults happen on Electric Power System, substation system is responsible to collect various protective relaying information and fault record information. Then information is sent to master system through communication network. According to them, power dispatcher can analyze and handle fault in time. So this system greatly improves the ability of fault analysis and the efficiency of fault handling. It can also improve the level of management of fault information.This study is combined with the project of a master system in JiangSu Province and FuJian Province. Firstly, this paper presents the master system's function orientation, and discusses it from three respects: the hardware platform architecture, the software platform architecture and the function design. The design of the hardware platform architecture considers the independency, the security, the dependability of the system. The design of the software platform architecture compares two feasible schemes and analysis their reasonability. The function design divides the whole system into some reasonable function modules based on classifications of fault information and various respects of fault analysis.Most electric power faults are transmission line fault. So the function of intelligent fault location on line is one of the most important functions of the master system. This paper then discusses fault location algorithm, presents an applied one-terminal fault location algorithm and new two-terminal fault location algorithms, then analyze the factors affecting the accuracy of fault location. The Two-terminal algorithm are more accurate. So the paper pays emphases on the problems such as the effect of unsynchronized data sampling, method based on different line models, and optimization of the calculation results etc. and solves them. The methods are simulated using data from MATLAB Power System models and tested using data from actual fault recorder. Finally, the method which computes the unsynchronized phasor angle based on the distributed parameter line model gets more accurate result. To make the result stable, the optimizing method using least square state estimation and statistics is described. Besides, based on the research of fault location algorithms, the paper presents the flow design of two new fault location software subsystem. To make it more practical and intelligent, problems existing in auto fault location subsystem such as parsing COMTRADE format files, digital filter, fuzzy fault diagnosis, selecting fault line and determining fault type are solved. Finally, the two subsystem have been developed and been tested and been tested.Using reasonable communication protocol is very important for the data exchange between the master system and the substation system. An extendable version of IEC60870-5-103 protocol is discussed and accepted. The protocol use IEC60870-5-101/104 for reference and is fit for TCP/IP network. With the release of the IEC61850, it is a trend to use IEC61850 as the protocol in this system. So this paper introduces the characteristics of IEC61850 standard, then constructs a system information model based on it and presents a possible and feasible communication scheme in future. Finally, according to present system, some suggestions are made for improving its capability to make it become a more powerful and perfect fault information process system.