Research On The Longitudinal Fault Location Of Active Distribution Network Based On FTU

With the development of new energy and the increasing penetration of its access to distribution network,the structure of traditional distribution network is more complex and the difficulty of operation management is increasing.Active distribution network can improve the ability of consumption of distributed power by flexibly managing topology structure to control the trend,consequently,which is a trend of the future smart grid construction.However,due to the complicated structure and multi-source operation,the fault analysis more difficult when the active distribution network is in the ground fault occurs.If it cannot be quickly and accurately excluded faults,the safe and stable operation of the whole system will be affected.Thus,it is one of the keys to ensure the quality and reliability of the active distribution network to quickly and accurately detect and isolate failures.In order to solve the problem of active distribution network fault location,the fault location problem is segment to simplify the difficulty of fault location.At the same time,the fault information collected by FTU is used to improve the speed and accuracy of the fault location.The main contents are as follows:1.A new fault location method based on graph theory is proposed to describe the dynamic characteristics of the active distribution network,which can solve the problem of the failure of the active distribution network caused by the complex structure and the misjudgement of the section.According to the electrical connection between nodes and branches in active distribution network,the method adopts graph theory to get the dynamic adjacency matrix and feeds back the operation state of network structure in real time,so as to enhance the capability of adjacency matrix to describe the dynamic characteristics of topological structure.2.Meanwhile,according to the fault characteristics of different situations,a single fault and multiple fault criteria are proposed.By identifying fault interval types,corresponding fault criteria are selected to enhance the flexibility and accuracy of fault judgement.3.A longitudinal fault location method based on gathering the information by multi-terminal FTU adjoined the fault branch is proposed to solve the problem of fault location in the complex branch of the power distribution network.The method takes advantage of the circuit characteristics of the digraph topology structure of thegrounding circuit of the two ends power supply,which counteracts the influence of fault point grounding resistance on fault location and improves the accuracy of fault location.4.On the basis of the fault section which has been determined,the longitudinal fault location is carried out,which can reduce the fault location range and eliminate the error caused by other links.The 13 node distribution network is used to simulate the proposed method,and the validity and accuracy of the method are verified under different fault conditions.