Research On Fault Identification And Diagnosis Of Distribution Lines

The topological structure of the distribution network is complex,and the operating conditions are numerous,so it is easy to cause failures.Distribution network faults account for relatively high faults in distribution network equipment,and single-phase ground faults account for more than 80% of total faults in distribution lines.In the single-phase ground fault of a small current grounding system,the arc-grounded faults are more detrimental to the distribution network because they are inherently unstable and difficult to predict.At present,most of the studies on single-phase arc ground faults are based on metal grounding or a fixed-resistance grounding resistance.This traditional grounding arc model cannot achieve the same results.Accurately reflect the actual situation of the failure,Therefore,it is very necessary to establish an accurate grounding arc model and perform fault simulation experiments to obtain more accurate characteristic information.In this paper,the single-phase metallic ground fault and the single-phase arc ground fault of the small-current grounding system under neutral grounding and neutral arc-suppression coils are studied in detail,and the distribution line is pointed out.In the research of fault identification and diagnosis in this respect,the analysis should be performed from the transient component of the capacitive current.In addition,the traditional grounding arc model is improved,and a simulation model that is more suitable for single-phase arc grounding faults in the small-current grounding system is established.Using the MATLAB simulation software,a single-phase metallic grounding fault and a single-phase arcing ground fault are simulated.The zerosequence current and zero-sequence voltage transient process and its characteristics are analyzed,as well as the characteristic quantity information of fault-line and non-faulty circuit zero-sequence current.This paper starts from the transient characteristics of the fault signal and uses the time domain analysis method of wavelet transform to identify and diagnose the fault after a single-phase metallic grounding fault or a single-phase arcing earth fault of a small-current grounding system in a distribution line.Research analysis.Using the combination of multi-resolution analysis and wavelet packet analysis to extract fault transient characteristics,and then using the actual detection device to perform simulation experiments and analyze the collected experimental data,it is possible to diagnose faulty lines and non-faulty lines.Identify the fault type,and finally propose the identification and diagnosis strategy of the fault of the distribution line.This method is more prominent in extracting fault transient characteristics than the traditional mode,enhancing the feasibility of the research,and this method is not affected by the type of fault.Therefore,adopting this effective method can realize the identification of the fault type and the diagnosis of the faulty line,and then can better study the single-phase earth fault and other typical grid ground faults of the overhead line to ensure the normality of the power supply system.Running and improving the operation quality of distribution lines are all of great significance.