Research On Distributed Traveling Wave Fault Location System For Transmission Line

With the development of modern power grids,the transmission voltage level of high-voltage transmission lines increases,and the transmission distance of transmission line also increases significantly.Timely and accurate fault location in the event of a transmission line fault prevents further expansion of the fault area,thereby improving staff efficiency.The transmission line traveling wave fault location technology has been widely promoted,but with the increase of transmission distance,the traditional double-ended traveling wave fault ranging algorithm can hardly meet the requirements of its ranging accuracy,and the emergence of distributed traveling wave fault ranging system for transmission lines makes up for the shortage of low fault ranging accuracy in long-distance transmission lines,improves the ranging accuracy,saves the staff’s overhaul time,and the reliability of power supply is It has a good development prospect.In this paper,the distributed traveling wave fault ranging system for transmission lines is studied,and the main research contents are summarized as follows:First,the basic principle of distributed traveling wave fault ranging is outlined,and the main structure of the system and the functions of each component are introduced.The technical problems of the distributed traveling wave fault ranging system are pointed out,and the problems are scattered in each component unit of the system,and the technical problems of each unit are studied separately.The technical problems in the system are divided into software and hardware problems.The software is mainly the design of distributed traveling wave ranging algorithm,while the key technologies studied in the hardware part are non-contact traveling wave signal extraction technology,non-contact CT energy extraction technology,data transmission technology,communication technology,and synchronous clock timing technology.By analyzing the progress of domestic and international research on some units,the design scheme of the relevant functional units in this paper is proposed.Secondly,in the software aspect,we mainly focus on the distributed traveling wave fault ranging algorithm,propose the algorithm strategy of the distributed fault ranging matrix algorithm for transmission lines,design the relevant distributed traveling wave fault ranging algorithm process as well as the correction zeroing algorithm and wave speed correction algorithm.The lower triangular matrix is constructed to avoid the reuse of data,and the nature of matrix rank is used for fault location.The algorithm flow of the traditional distributed ranging algorithm,which selects the area first and locates it later,is changed to realize the simultaneous selection of fault area and fault point location.The 220 k V transmission line model is built and set up with faults by PSCAD software to generate transmission line fault data,and the fault data is processed by MATLAB software and simulated and verified by using the distributed traveling wave fault ranging matrix algorithm.Finally,in the hardware part,a non-contact traveling wave signal extraction scheme is designed by analyzing the traveling wave signal extraction method.The voltage type non-contact traveling wave signal extraction uses the electric field to extract the traveling wave signal,and the current type non-contact traveling wave signal extraction uses the magnetic field to extract the traveling wave signal.The current type non-contact traveling wave signal extraction uses the self-integrating operation of the Roche coil to extract the high frequency traveling wave current signal.The COMSOL Multiphysics finite element simulation software is used to build a model to simulate the voltage signal extraction scheme,and an experimental platform is built to experiment the current extraction scheme to verify the feasibility of the non-contact traveling wave signal extraction module scheme.