Based On The Skin Effect Of Zinc Oxide Lightning Arrester Failure Analysis

Because China has a vast, complex terrain, the long distance transmission Group Gallery is bound to go inevitably through a complex Gallery topography, combined with the existence of significant differences in climate conditions, operating conditions of the transmission line will certainly pretty bad, such as snow, rain, typhoons and others, more serious harm is lightning. Because the long-distance transmission lines go through the complex terrain, such as mountains, rivers, plateaus, wetlands, and steep slopes, rivers and other harsh terrain large span erection of transmission lines are vulnerable to lightning, so the lightning protection of the transmission line seems increasingly important. As of today has been recognized as the most advanced lightning protection technology products-Zinc oxide surge arresters (Hereinafter referred to as MOA), will also widely used in long-distance transmission line system.Although MOA is now recognized as the most advanced lightning protection products, but limited by the arrester manufacturing technology technical level is still far from reaching the required technical standards lightning, and many have been put into operation MOA are more or less had appeared some failures. MOA is widely used in the power system surely will bring many MOA’s failure problems, the domestic and foreign scholars and universities mainly concentrate on the had been recognized reasons for failure-aging and damp, but the cause is still a considerable part of the arrester failures and not identified. Therefore, this paper presents and discusses the skin effect is one of the reasons MOA’s failure:either the lightning or switching overvoltage overvoltage caused current are present more serious skin effect when the discharge current relief to the earth, which will cause some several problems of MOA’s edge localized breakdown during normal operation, the non-linear voltage characteristics of the local region in the long run are often excellent breakdown will more prone to failure even explosion; what is more have the opposite effect, resulting in the protection devices which installating MOA are more prone to ground fault.In this paper, theoretical analysis, the experiment proved the correctness of the skin effect is one of the reasons for MOA’s failure. First introduced the microstructure and the working principle of nonlinear voltage characteristics of MOA valve, MOA’s principle and some reasons of its failures; then use the Fourier decomposition of the lightning current, three mathematical functions models are closely related to the frequency and briefly describes the produced mechanism of the skin effect learn to which is also a function of the presence of a fixed frequency, prove the existence of skin effect when MOA in normal operation, the presence of skin effect through simulation experiments show that the impact of voltage zinc oxide varistor valve, and there will be many times the edge of a partial breakdown and analysis the breakdown position according to the experimental data, draw to the conclusion of the valve resulting in nonlinear partial breakdown voltage characteristics deteriorate derived phenomenon and breakdown point in the edge; finally, according to the simulating breakdown experiments of finished MOA, carried out after the breakdown of MOA’s disintegration analysis showed that the finished MOA also appeared edged and localized breakdown phenomenon further demonstrate the presence of the skin effect when MOA in normal operation, and thus more fully demonstrate the skin effect which is one of the reasons for MOA’s failures.