The Simulation And Analysis Of Induced Overvoltage In 35kV Distribution System

Lightning-induced voltages are a major cause of outages in power distribution systems. In this paper, we study the induced voltages across insulator string by directly lightning strokes on 35kv transmission line tower.In the paper, based on the Field Cancellation Method, we apply the simple method to calculate the lightning-induced voltages taking into account the effect of the dart leaders. The calculation of software based on the simply method is programmed. It not only can calculate induced voltages under different parameters of 35kV transmission line towers and lightning strokes but also can calculate induced voltages on other voltage class towers. Then, the paper discusses the effects of the following parameters on the peak value of induced voltage and on the shape of the induced voltages: propagation velocity, lightning current peak value, tower equivalent radius, the height of the overhead line. And we can use Matlab to calculate the lighting induced voltage easily.Finally, we study the lightning impulse protection methods of the distribution network of Zhongyuan Oil Field based on the theory. In this paper, the special natural conditions and the current protection of lightning impulse of Zhongyuan Oil Field region would be considered first. This paper analyzes the perils and its merits of lightning protection device targets and designs of lightning on-line monitoring devices and analysis software. According to the results of on-line monitoring devices, we draw up line lightning protection measures which suitable for 35kV Transmission lines of Zhongyuan Oil Field.