Research And Application Of Single-phase Earth Fault Location And On-line Monitoring In Distribution Network

The distribution network is the direct link in the power system and the user connection,its coverage is wide,the running environment is complex,the feeder line branch is much branched.Because of the characteristics of "closed-loop structure and open-loop operation",the distribution network has many branches,complex structures and frequent topology changes.It is very difficult to determine the fault location and fault location.Therefore,the technical and economic factors determine the short-circuit fault location of the distribution network.Grounding fault location has its particularity and complexity,which has been a significant and extensive technical problem that has not been solved for many years.In this paper,the basic principle of short-circuit fault and ground fault of distribution network is studied.The basic principle of the fault location and detection of distribution network fault and short-circuit is explained theoretically.At the same time,this paper designs a set of on-line fault monitoring system for distribution network based on wireless communication technology.The system mainly includes three parts: line information collecting device,data base station and distribution network monitoring center.The data base station is used for collecting the line information collected by the line collecting device and sending the information to the distribution network monitoring center for processing.In the energy,the line collection device using self-energy mode to function,and the data base station using solar panels for energy.In the current measurement,this paper uses the current sensor to collect the current information of the line.In the fault location,this paper presents three kinds of fault line selection methods,namely the fundamental zero-sequence current line selection method,harmonic current line selection method and active component method,respectively,and studied the practical situation of each method.At the end of the paper,the test results of the system in practical engineering are given.The results show that the system can successfully monitor and locate the fault of the distribution network.The system uses a multi-point distributed measurement of the way,a number of feeder lines on the electrical measurement and acquisition,through wireless communication will be sent to the collection of the main station background,in the background of the data analysis and analysis to determine the line Running state,when the line fails to locate the fault line.At the same time,the system can be applied to many kinds of fault location methods,such as synchronous acquisition of electric quantity,wireless communication,data storage,status monitoring and fault location.It provides the basis for optimal operation,fault isolation and fault reconstruction of distribution network.