The Distribution of the Discharge Current from a Local Discharge on an Electrolytic Solution and the Solution Surface

采用电解溶液表面模拟湿污绝缘子表面。当电压施加到溶液表面时，局部放电在溶液表面传播。考察了电解溶液局部放电与溶液表面的电接触。从局部放电到溶液的电流分布是由放置在溶液中的探针测量的电位分布估计出来的。溶液的电阻率约为80 ~ 370Ω cm，施加电压分别为2/80 μs、10/800 μs和100/2500 μs。在每组实验条件下，施加电压的峰值为50%闪络电压V_<50>的1.05 ~ 1.4倍。结果发现，大部分放电电流从局部放电的尖端部分流出，局部放电柱的电流相当低。此外，发现从局部放电到溶液的电流分布几乎不受溶液电阻率、外加电压峰值或外加电压波形的影响。

An electrolytic solution surface was used to simulate the surface of wet polluted insulators. A local discharge propagates on the solution surface when the voltage is applied to the surface. The electrical contact between the local discharge on the electrolytic solution and the solution surface was examined. The distribution of the current from the local discharge to the solution is estimated from the potential distribution measured with the probes placed in the solution. The resistivity of the solution is varied from about 80 to 370Ω cm. The impulse voltages of 2/80 μs, 10/800 μs and 100/2500 μs are used as the applied voltage. The peak value of the applied voltage was 1.05 to 1.4 times the 50% flashover voltage V_<50> under each set of experimental conditions. As a result, it is found that most of the discharge current flows from the tip part of the local discharge, and the current from the local discharge column is considerably low. Further, the distribution of the current from the local discharge to the solution is found to be hardly influenced by the resistivity of the solution, the peak value of the applied voltage or the applied voltage waveform.