特高压输电线路长串绝缘子的电压分布很不均匀,所以需要对其电压分布进行研究。为此,采用模拟电荷法和边界元法相结合分别计算出各片瓷绝缘子与杆塔、导线等之间的杂散电容,并应用此计算结果构建链式电路的方法,综合各种影响因素简洁有效地计算分析了交流1 000kV输电线路瓷绝缘子串在干燥及均匀污湿状态下的电压分布情况。计算结果表明:绝缘子的自电容对电压分布的影响不是很大,均压环是控制特高压绝缘子串电压分布的最主要方法;绝缘电阻在300MΩ以上时,绝缘子的表面状态对绝缘子串的电压分布影响很小,泄漏电导在一定范围的增大可以使绝缘子串电压分布更均匀,若采用半导体釉绝缘子,每片的电阻在10~20 MΩ左右即可;低值绝缘子加剧了电压分布的不均匀性,对其邻近绝缘子影响较大,当其处于导线侧附近时,临近绝缘子的最大单片电压降将增加到30kV以上。
The voltage distribution along the long insulator strings of UHV AC transmission lines is very non-uniform,so it is necessary to research the voltage distribution.Using the combination of the charge simulation method(CSM) and the boundary element method(BEM),we respectively calculated the stray capacitance between every ceramic insulator and towers or lines,and applied these results to construct a chain circuit.Then we efficiently calculated and analyzed the voltage distribution along the insulator strings of the AC 1 000 kV transmission lines under dry and wet conditions.The calculated results show that the self-capacitance of the insulator has a slight effect on the voltage distribution,and using grading rings is the main measure to control the voltage distribution;the surface condition of the insulator has little effect on the voltage distribution when the insulator resistance is over 300 MΩ and the increase in the leakage electric conductance within certain range can improve the uniformity of the voltage distribution;if the semiconducting glaze insulator is used,the resistance of each insulator should be about 10~20 MΩ;the faulty insulator will aggravate the uniformity of the voltage distribution and the maximum voltage drop across the insulator may be over 30 kV when the faulty insulator is nearby the line.