35kV并网光伏电站低电压穿越检测装置的绝缘配合优化设计

Insulation Coordination Optimization Design for Low Voltage Ride Through Test Device of 35 kV Grid-connected Photovoltaic System

为了避免35kV并网光伏低穿检测装置在高海拔环境运行过程中发生装置内电抗器抽头对周围零电位或抽头间放电等绝缘击穿事故,文中结合产品设计过程中操作过电压测量实验,利用有限元法对低压穿越检测装置在运行过程中耐受高幅值操作过电压条件下的电场分布进行仿真计算,分析了装置内绝缘薄弱区域并提出优化建议。结果表明:在抽头间安装绝缘挡板、增大抽头处螺母表面积、提高接线铜排的曲率及抽头之间的电气间隙等措施可以使装置内原本畸变电场分布更加均匀,最大场强值降低57.2%。

In order to avoid insulation breakdown failure of reactor tap to the surrounding zero potential or between tap in process of 35 kV grid-connected photovoltaic system operation in high altitude environmen, in this paper, combining with operating overvohage measurement test in process of the production design, the electric distribu-tion in the condition of high amplitude operating overvoltage by finite element method, the insulation weak area in the device is analyzed and the present optimization suggestions are presented. The conclusion is： adding insulation board between wire tap, increasing the surface area of nut, improving curvature of wire tap and the electric clear- ance can make the electric field which is distorted more even, the max field strength would be reduced by 57.2%.