Study On New Type Of Travelling Wave Based Fault Locator For Transmission Lines

At home and abroad, with the development of electric industry, especially in the construction and use of ultra high voltage transmission line, traveling wav e fault location device has become an important part in transmission line.Travel ing wave fault location device provids an effective method to locate the fault quickly and accurately so that the economic loss caused by power outages coul d be reduced.Therefore the study on traveling wave fault location device shoul d step further.Faults include permanent fault and transient fault. The majority in these fault are transient fault, for the transient fault, in order to distinguish these influenc e, which is caused by the line insulator aging or by the wind the branches sw ing or by the lightning over voltage, and discover the hidden fault timely and effectively so that we can take measures to avoid accidents from happening ag ain, the location of the fault point must be quickly and accurately.Due to the advantages of traveling wave fault location, which is not affected by the transformer saturation, as well as accuracy position, this method can sat isfy the working demand of power staff so that it has got very good applicatio n in traveling wave fault location of high voltage transmission line. The fault s ection detection is accomplished by the traveling wave fault location using the reflection time of initial traveling wave and traveling waves velocity of propag ation in the overhead power lines. With the development of the ultra high spee d data acquisition unit as well as the application of T-GPS, the ranging accura cy with the traveling wave fault location device is higher.This article presents a new type of traveling wave fault location device base d on previous experience. First, it summarized the main working principle of tr aveling wave fault location device. Next, according to the limitation of the sin gle and double side ranging principle, a combination of traveling wave fault lo cation scheme is proposed. According to the actual operating experience, we gi ve a detailed introduction for the traveling wave fault location device with the extraction of traveling wave signal, ultra high speed data acquisition and stora ge, traveling wave signal arrival time’s calibration and other key technologies. Furthermore a detailed analysis for two aspects of hardware/software is provide d in the key element of the fault location devices. In this paper, the wavelet tr ansform, validated in the later part of simulation,is introduced to solve problem, which is hard to find the exact arrival time in the process of traveling wave signal analysis because of the influence of the transform and transmission for t he head of wave. In addition, the distance measuring device is tested its functi on by the traveling-wave based calibrator.