Fault location method for multi-segment hybrid line based on traveling wave time difference

Abstract

With the increase of economic level and power demand, transmission lines are becoming more and more important in the national economy. To protect the normal operation of lines in the distribution network, fast and efficient fault location after transmission line failure has become a research hotspot. There are many fault location methods for distribution hybrid lines in the society. Double ended ranging method in traveling wave method is widely used because of its high accuracy and few restrictions. However, the two terminal ranging method in traveling wave method involves many influencing factors, which leads to unstable wave speed. In addition, the time delay of the detection device causes time synchronization and other factors, which will reduce the measurement accuracy of traveling wave method. Therefore, a new modified wave method needs to be studied for fault location of transmission lines. At present, traveling wave fault location of distribution hybrid lines has become a research hotspot at home and abroad. Aiming at the previous fault location method, an improved traveling wave fault location method for hybrid transmission lines in distribution network is proposed, and the improved two terminal fault location method is used to improve the accuracy. An improved single and double ended combination method is proposed. Using the improved two terminal method in the mixed line traveling wave of distribution network to estimate the time difference between the refracted wave and the bus, and then ranging method is used for positioning calculation, which reduces the impact of single ended reflection wave attenuation on the measurement time. However, the estimated time obtained by using of the double ended traveling wave method of the distribution king hybrid line is related to the traveling wave velocity. An improved fault location method for distribution network hybrid lines is proposed, which determines the fault location through the time difference of fault speed in the bus and relevant data.