Study On The Location Of Single-phase Connection Section In Distribution Network

China's distribution network mostly adopts the low-current grounding operation mode,which helps to improve the reliability of power supply.However,when a single-phase ground fault occurs,the fault current signal is weak and difficult to detect.If the fault is not accurately located,it may further cause phase-to-phase short circuits.A fault trips the line and interrupts power supply.At present,the line selection technology for small current grounding faults has been basically mature,and the problem of fault location has not been well solved.In this paper,a method of using D-S evidence theory to solve the problem of locating the fault section is proposed based on the fusion idea,which lays the foundation for solving the problem of single-phase ground fault section locating.Based on small current grounding system single-phase grounding fault equivalence model,research completed,fault point same side-to-side side zero zero-order current waveform special expedition,special announcement:fault point same side-to-side zero-order current waveform difference small,fault point Difference between zero and zero current waveforms.Discriminant signals Signal distance relative position localization method Sum phase relation Numerical position localization method Progress analysis,analysis assertion:Signal mutual distance performance efficiency measurement zero order current waveform difference difference,correlation coefficient performance capability measurement status.Zero-order current waveform similarity,two types of method,zero-order current analyzer,mutuality,fusion identification,high-section stereotacticity.Submission of the D-S verification method.Each point after the occurrence of a fault at the head of the fault FTU gathering 1/4 period zero order current,calculated signal mutual distance sum correlation correlation numerical localization measure;second,structure approximate distribution function,general method approximate distribution function progression correction Comprehension;after that,the basic approximate ratio number basic judgment of small number of faults,the existence of a fixed fault road,the basic rough ratio number Locating the fusion theory Fault zone stage.In order to verify the reliability of the fault section location method based on d-s evidence theory proposed in this paper,the 10kV distribution network simulation model was built by MATLAB,and the simulation verification was carried out under different fault conditions.The section location method is verified by the simulation experiment platform of the low pressure system of 380V coal mine in the laboratory.The effectiveness and applicability of the fault location method are proved by a lot of simulation and experiments.