750 kV变电站门形构架双联耐张绝缘子串均压环选型研究

变电站门形构架绝缘子金具表面电场强度超过规定限值后，会在金具尖端或均压环外端面形成电晕放电，增加了站内整体电磁噪声和电能损耗，尤其海拔高度对电晕放电场强限值影响较大。以海拔高度大于1 000 m的750 kV沙州变电站为例，采用ANSYS仿真计算了变电站门形构架双联耐张串绝缘子金具不同均压环管径、连接板表面的电场强度，获得了相应的电场分布图，通过对比确定了750 kV变电站门形构架双联耐张串绝缘子均压环优化选型方案。在天气较好条件下，分别测量了沙州750 kV变电站门型构架四分裂母线与跨线处的噪声，1～6 kHz频段内噪声最大值均低于相关标准的昼间要求，这验证了金具优化后效果较好。

Study on Model Selection of Shielding Ring for Double-unit Strain Insulator in 750 kV Substation Door-type Frame

Corona discharge will happen on tip of electric power fittings or end face of shielding ring when electric field strength exceeds the normal threshold-value, meanwhile it increases the whole electromagnetic noise and electric energy loss in substation, especially for corona discharge electric field threshold-value in high altitude region. Take the 750 kV Sha-zhou substation whose altitude is higher than 1km as an example, the paper calculated surface electric field for different diameter of shielding ring and connecting plate fittings for double-unit strain insulator of door-type frame in substation through ANSYS, obtained the electric field distribution map accordingly, determined optimized model selection scheme for shielding ring of double-unit strain insulator in 750 kV substation door-type frame through comparison, and then measured noise for four split bus line and outlet line of door-type frame in 750 kV Shazhou substation obviously under sunny weather, the result showed that the maximum noise between 1 kHz to 6 kHz is lower the relative requirements in daytime, it proved the effect is better than that of before fitting optimization.