Research On Fault Location Of Small Current Earth Fault Based On Distributed Intelligence

Distribution network is an important part of power system,which is the middle link between substation and users.Distribution network troubleshooting is one of the main contents of distribution automation studies,but the main fault form of distribution network fault is small current grounding fault,which accounts for more than 80% of the total fault form.Although small current ground fault do not affect the three-phase load user power supply,a long time with a faulty operation will endanger the equipment and human safety,and seriously affects the normal life of users.Currently,there are mainly two control modes for small current grounding fault location in distribution network: local control mode and centralized control mode.However,these two control mode fault processing time is long,which is possibility resulted in the occurrence of fault conversion,equipment damage and even hazarded human and animal safety.Therefore,it is urgent to study the fast positioning method of small currentgroundingfault.In view of the disadvantages of the existing small current grounding fault location methods in distribution network,a fault location method based on distributed intelligence is presented inthis paper,in which the factors that affect the distributed intelligent small current grounding fault location method are discussed and the effective measures to improve the fault location method are put up.The main contents of this paper are as follows:(1)the grounding mode and characteristics of neutral point in distribution network are summarized,and the steady and transient characteristics of small current grounding fault are introduced,by which the fault location can be realized;(2)the types of small current ground fault location in feeder automation are analyzed and compared,and the principle,process and advantages and disadvantages of fault location in distribution network are discussed in detail,based on the above,a distributed intelligent small current grounding fault location method is proposed;(3)the principle,process and fault tolerance of the distributed intelligent fault location method are studied,the main factors of affecting the distributed intelligent small current grounding fault location method are discussed,and the solutions of different factors are proposed;(4)This paper analyzes the communication technology of distributed intelligence,including information transmission delay and signal synchronization,a new method is proposed to solve the problem of signal synchronization,which is based on the detection of the maximum amplitude of the transient zero sequence current;(5)The ATP simulation model of distributed intelligent small current grounding fault is built,and the static simulation experiment was carried out in the research center of smart grid,which involved testing the influences of different grounding resistances and different initial phase angles on the method,and by which the feasibility of the distributed intelligent fault location method is finallyverified.In this paper,a distributed intelligent small current grounding fault location method is proposed,which does not require the participation of the main station,the communication pressure is small,and the fault section can be located inan ideal time,effectively reducing outage time and loss.The research results are of great significance to the improvement of small current grounding fault location method and also toimprove the reliability of powersupply.