强降雨下不同安装角度的空心复合绝缘子冲击闪络特性研究

Impulse Flashover Characteristics of Hollow Composite Insulators with Different Installation Angles Under Heavy Rainfall

随着全球气候变暖,特大暴雨、雾霾、暴雪等极端天气频发,其中暴雨天气已成为电力设备安全运行的严重隐患之一。空心复合绝缘子已被广泛应用于各种电力设备中,但对于强降雨条件下空心复合绝缘子的冲击闪络特性缺乏系统的研究。以额定电压220 kV空心复合绝缘子为试品,进行了强降雨条件下空心复合绝缘子的冲击放电电压试验,研究结果表明:强降雨条件下,降雨强度对于空心复合绝缘子的50%雷电冲击闪络电压影响不大,而50%操作冲击闪络电压随着降雨强度的增大而减小,符合负幂指数关系;雨水电导率的增加对50%操作冲击闪络电压有所影响,但相对降雨强度对其影响小得多;同时,改变空心复合绝缘子的安装角度也会导致50%操作冲击闪络电压的不同,在标准淋雨条件下,空心复合绝缘子与水平呈60°夹角安装时绝缘强度最优。

With the global warming,extreme weather such as heavy rain,haze and blizzard happen frequently,among which the rainstorm has become one of the serious hidden dangers for the safe operation of power equipment. In recent years,hollow composite insulators have been widely used in a variety of electrical equipment,but there are lacks of systematic research on the impulse flashover characteristics of hollow composite insulators under heavy rainfall conditions. In this paper,the hollow composite insulators with rated voltage of 220 kV are used to conduct impulse voltage flashover test under heavy rainfall conditions,and the test results show the rainfall intensity has little effect on the 50% lightning impulse flashover voltage of the hollow composite insulator under heavy rainfall,while the 50% switching impulse flashover voltage decreases with the increase of the rainfall intensity,satisfying the negative power exponent relationship;the 50% switching impulse flashover voltage decreases with the increase of rainwater conductivity. The increase of rainwater conductivity has some influence on the 50% operating shock flashover voltage,but the relative rainfall intensity has much less influence on it;While,changing the installation angle of the hollow composite insulator will also lead to the 50% switching impulse flashover voltage difference. In the standard rain conditions,the hollow composite insulator under the level of 60°angle installation has the best dielectric strength.