电网络法计算交流特高压绝缘子串电压分布

特高压输电线路绝缘子串较长,电压分布很不均匀。为给线路工程提供设计参考数据,利用电网络法并结合试验,计算和分析了56片绝缘子串在干燥及污湿情况下的电压分布。结果表明:绝缘子劣化将加剧电压分布的不均匀;采用自身电容较大的绝缘子,增加杆塔高度和横担长度均能改善绝缘子串的电压分布;泄漏电导增大和不同位置绝缘子杂散电容的差异也可减小电压分布的不均匀性。在工程应用中,采用自身电容较大的绝缘子对改善特高压绝缘子串电压分布的效果最为明显。

Calculation of Voltage Distribution Along Insulator Strings of UHV AC Transmission Line by Electric-network Method

The insulator strings of UHV AC transmission lines are very long, and the voltage distribution along them is non-uniform. By using the electric-network method and the experimental results, this paper calculates and analyzes the voltage distribution along cap-and-pin insulator strings of 56 units under the dry and wet conditions. The results show that the zero-value insulator in the string will aggravate the voltage distribution; the non-uniformity of the voltage distribution can be released by using the insulators with a larger self capacitance, enhancing the height of the tower or increasing the cross arm. The appearance of leakage electric conductance and the differential of the stray capacitances along the insulator string can also improve the uniformity of the voltage distribution. To meet the needs of practical project, the more effective method for improving uniformity of the voltage distribution is to use the insulators with the larger self capacitance.