Research And Application Of Singlephase Grounding Fault Location Technology In Mine Distribution Network

With the continuous development of intelligent mines,various types of mine electromechanical equipment have been introduced,and the degree of mine automation is getting higher and higher.At the same time,it has also increased the requirements for the safety and stability of the mine distribution network.Mine power distribution network has many branches,wide coverage and complex geographical environment.Various factors lead to frequent distribution network faults,of which single-phase ground faults account for more than 85% of the total number of faults.Therefore,after a single-phase ground fault occurs,how to quickly and accurately troubleshoot the fault,shorten the power outage time,and reduce the damage of the single-phase ground fault to the insulation performance of the distribution network equipment become critical.This paper studies the single-phase grounding fault location technology of the mine distribution network for the above problems,focusing on the following aspects:First,the signal current injected from the fault phase using the injection signal method only flows to the fault ground point,locate the fault feeder,and then the corresponding algorithm calculates the exact location of the fault point based on the information uploaded by the detector.By comparing the characteristics of the DC and AC injection methods,the effectiveness of the two applications in the mine is analyzed,and the AC signal injection method is used as a single-phase ground fault location method for the mine distribution network.Second,improve the fault location algorithm of the section and improve the accuracy of the fault location algorithm.By modeling and analyzing the topological structure of a coal mine distribution network system diagram,combining the matrix logic operation section positioning algorithm and the Amoeba iterative algorithm,a fault location algorithm based on detection information is proposed to make fault location accurate to the fault location.Simulation verification of the algorithm,the simulation results show that the average error of the algorithm is about 0.35%,which can meet the accuracy requirements of the system.Furthermore,for the problem that the current injected by the signal injection method is shunted by electrical parameters such as the distributed capacitance of the line and the current signal flowing through the signal detector is weak and difficult to collect,the positive effect of noise in the Stochastic resonance theory and the nonlinearity Bistable system to enhance the injected signal strength.Through the application of mixed-frequency signal modulation,the signal detector’s filtering method for the injected signal current is optimized to improve the accuracy of the injected signal current detection and the reliability of fault location.Through model simulation,the feasibility of Stochastic resonance theoretical mixing modulation method is verified.Finally,the design of the single-phase grounding fault location system of the mine distribution network is carried out.Design the mine communication network structure based on 4G network,improve the signal detector,elaborate the software design,and make the theory of this paper have an application carrier.