SF_6/N_2混合气体中金属微粒对GIL盆式绝缘子表面电荷积聚特性的影响

Influence of Metal Particles on Surface Charge Accumulation Characteristics of GIL Spacer in SF_6/N_2 Mixture

在0.5MPa 20%SF_6/N_2混合气体中,利用静电探头和电荷反演算法测量并计算了金属微粒附着时盆式绝缘子的表面电荷分布,并研究电压类型和金属微粒长度对表面电荷分布影响。结果表明,金属微粒将加剧绝缘子表面电荷积聚并严重畸变金属微粒处电场。在直流电压下绝缘子表面电荷存在三种积聚形态,即同极性电极注入电荷、金属微粒附近双极性电荷及随机分布电荷,而在雷电冲击电压下绝缘子表面仅存在金属微粒附近双极性电荷及随机分布电荷。当金属微粒超过5mm时,直流电压下注入电荷区的存在将导致金属微粒附近积聚电荷量减少,雷电冲击电压下随机分布电荷的存在也将导致金属微粒附近积聚电荷量减少。

The surface charge distribution of spacer with metal particles attached in 0.5MPa 20%SF6/N2 mixture was measured by an electrostatic probe and calculated with an inverse algorithm,and the influence of applied voltage type and metal particle length were studied.The results show that metal particles can increase the surface charge accumulation and greatly distort the local electric field.Under DC voltage the surface charge distribution can be divided into three different patterns,including the homo-charges by electrode injection,bipolar charges around the metal particles and random charges.However,under lightning impulse voltage,there are just bipolar charges around the metal particles and random charges existing.When the metal particle is longer than 5mm,under DC voltage,the accumulated charge near the metal particles will decrease for the existing of charge injection region,and under lightning impulse voltage,the existing of randomly distributed charge will result in the same phenomenon.