Study On Integrated Lightning Location Method For High Voltage Transmission Line

The lightning location for transmission lines is of great significance to help power line maintenance crews to search for fault point quickly and restore power transmission without too much delay quickly. In order to solve some deficiencies of the existing Lightning Location System(LLS) and traveling wave location methods in this paper, a series of studies is carried out as follows:A new lightning location algorithm based on Modified Fruit Fly Optimization Algorithm(MFOA) is proposed in this paper to solve the problem that lightning location iterative algorithms of the existing LLS are easy to diverge caused by the difficulties of determining the initial value. MFOA overcomes the problem that Fruit Fly Optimization Algorithm(FOA) is easy to fall into local minima, and then apply MFOA to the lightning location. The problems of the existing lightning location algorithms can be solved by the proposed method.To solve the problem that the locating accuracy of the single-ended traveling wave method can not be guaranteed because of the difficulty in identifying the reflected wave fronts from the fault point and the opposite terminal of fault line(traveling-wave fronts),a new combined lightning locating algorithm for transmission lines based on LLS and single-ended traveling wave is proposed in this paper. Firstly,existing LLS is applied to recognize the lightning distance approximately. Then, the accurate arriving times of wave fronts are obtained with this approximate distance and the line parameters, which can identify the reflected wave fronts from the fault point and the opposite terminal of fault line. Finally, accurate results are obtained with the single-ended traveling wave method.Thus the problem that traveling-wave fronts cannot be accurately identified can be solved by the proposed method.To overcome the existing traveling wave device’s the shortage that is difficult in identifying lightning stroke, a method based on time-domain waveform characteristics is proposed. Firstly, normalize the current traveling waves, obtain the derivation of the normalized current traveling waves, and recognize lightning and short-circuit with the maximum slope(the maximum steepness). Secondly, using the characteristics of symmetric current traveling waveform induced by lightning fault and that of asymmetric current traveling waveform generated by lightning fault within a very short interval, the energy ratio of the two sides of the time axis is applied for the identification of lightning interference and lightning fault. So lightning interference and lightning faults and short-circuit can be recognized by the proposed method.