Design And Development Of Traveling-wave Fault Location System Of High Volt Power Lines

With quick developments of power system in our country, EHV power lines take a lead role in power system more and more. Safety and economical running of them have important economic and social senses. Because of the bad working environment of power lines, the faults often happen and are found difficultly. Therefore, quick and correct finding of fault location not only can eliminate fault and recover electricity quickly, but also play an important role in the whole power system with safety, stabilization and economical run.Because of the traditional fault location based on fundamental components is easy to be affected by transition resistor, fault type etc. Thus, its location accuracy is low and it can not satisfy the need of power transmission. Nowadays, with the development of computer, correspondence and measure technology, fault location of power lines based on traveling–wave develops widely in the protective relay in recent years.Fault location based on traveling–wave is mainly sorted two types: current and volt. However, using current is necessary to measure current traveling-wave on each line of substation, which causes complicated location system, high requirements of hardware and correspondingly low project flexibility. In case of voltage traveling-wave location, it is only necessary to measure bus bar voltage of substation, thus, fewer measuring signals , simplified fault location system, high flexibility are guaranteed. Also, it is more convenient to build the fault location system based on whole transmission power system. So the research of new fault location system based on the traveling-wave of the voltage will be significant in theory and expansive foreground in application.The paper firstly introduces the basic methods of fault location based on stable and transient variables, and then analyzes and summarizes the fault location from the point of actuality of its research and direction of developing. On the basis of the research of others the paper demonstrates the feasibility of a new idea that traveling-wave fault location based on Capacitor voltage transformer (CVT) secondary signal under emulation. Then aiming at the characteristic of application of fault location based on traveling-wave, the paper gives the meaning of detecting the head of wave based on wavelet and applied measures to the detecting during the processing.The emphases of this paper are located on the designs and development of hardware and software of new fault location system based on Capacitor voltage transformer (CVT) secondary signal. It presents the principia and functions of hardware and realizing project of high speed data sampling system (DSP+FPGA) based on PCI bus, and then particularly introduces the basic structure, function characteristic and realizing theory.The designs and developments of soft of sub-hardwires are important to the new fault location system. The main work contains the realizing of soft in DSP, FPGA and PC014. By the special soft design AD sampling under the frequency of 5MHz come true and the storage of big data file using the controlling of EDMA in DSP. Lastly, this paper presents how to realize the communication between the PC104 and HPI to completing the transfer of data files.Then, the paper mainly presents the design and development work from the fault location software and management software including the principia and requirements of up-soft. In the fault location software, it gives the location realizing upon conjoining the manual and automatic location. From the original wave of phase volts and line volts and the wave after wavelet-transform, we could get abundant information about the head of wave and give the basis of manual choosing line and excepting this we can realize single-side fault location in the manual location software under engineering experience. Also, this paper presents the needing of function and design characteristics of management software and particularly introduces the realizing of each function in the VC development. Lastly, it presents the foundation of communication system and the data transferring under the FTP.