Research On Series Arc Fault Location In Low Voltage Distribution System

In low voltage distribution systems,unpredictable series arc fault often occur when degraded and aged transmission lines are in bad contact with each other.A number of methods have been developed to detect this fault to prevent fire accidents,but these methods are not able to locate series arc fault in the transmission line mode of operation.Therefore,this paper will analyze the current and voltage signals of the transmission line with single-phase load,and build the equation related to the fault location.Based on this,the fault location will be found.This research is conducive to the timely maintenance of transmission lines,which will greatly reduce the hard work of manual hunt.Firstly,an experimental platform for series arc fault location of 220 V transmission lines was developed.Secondly,the experiment platform was used to simulate the series arc fault at different connection points of transmission lines under different current levels and power factors,and the current and voltage signals of power supply and load terminals were collected.Then,the characteristic analysis was carried out,and the voltage signal at the load end was pre-processed by CEEMD decomposition,and the influence of fault location on information entropy was analyzed.The influence of fault location on voltage and current signals at two terminals was also analyzed from the effective value and the total harmonic distortion rate(THD).Then,based on the exact equivalent model of transmission line,the location equation between current and voltage signals and fault location was established.The influence of power supply and load on the location method was analyzed by using FFT to transform to frequency domain.The effectiveness of the method was verified by taking six fault points in the middle of transmission line as examples.Finally,the error range of transmission line was analyzed when the connection point of transmission line was not known beforehand.The results show that the fault location method proposed in this paper will be affected by the power and load terminals.After the two connection points of 30 m and 230 m are removed,the fault location can still be accurately located in the middle section of the transmission line.If the location of transmission line connection points is not known beforehand,the fault points can not be accurately identified within the fault point range of 4m to 6m,and the location method can still be applied beyond the error range.