Research On Identification Of Lighting Stroke And Locating Position In Traveling Wave Fault Location

Transmission lines fault location device based on travelling wave has been widely applied in power system now. The application of fault location device is of great consequence to improve the security,reliability and economy of transmission lines. The accuracy of traveling wave fault location would be affected by lighting stroke in the case that fault point and lighting point are different when the fault is caused by lighting. The disturbance caused by lighting strikes is discussed in the paper, and the fault location method under the condition of lighting stroke is presented in the paper .The main contents of the thesis cover the following:1. The transient characteristic difference between the common fault current and lighting fault current are described in the paper. PSCAD/EMTDC simulations under different fault conditions provide the fault current data which are used to analyze the transient characteristic difference. The simulation result show that there are difference in following four aspects: gradient of fault current,energy distribution,phase deviation and transient energy of non-fault phase.2. Based on the transient characteristic difference, the paper proposed the identified criteria of lighting stroke and the features of criteria are also discussed. The identified method of lighting fault based on the criteria is presented in the paper and the issues related to identification of lighting stroke for example: the fault terminal identification, are also discussed in the paper. The analysis of existing example verified the validity of the method presented in the paper.3. The fault location method which based on the reflected wave from fault point is proposed in the paper under condition of lighting stroke fault. the method achieved the fault location through the calculation of relative distance between lighting point and fault point. The factors affect the precision are also analyzed in the paper. The validity of the method is proved by the EMTDC simulation and existing examples.