750kV变电站末端门架绝缘子串均压特性多参数差异性研究

Study on the Multiparameter Difference of Voltage Equalization Characteristics of Insulator Strings of 750kV Substation End Portal Frame

变电站紫外观测发现,750 kV变电站末端门型架绝缘子串相对其他位置电晕现象较为严重,因此对不同类型绝缘子串的均压特性进行差异性分析。搭建750 kV变电站三维模型,对带跳线和不带跳线绝缘子串的均压特性进行对比,利用子模型网格技术和模型细节简化技术对整体模型进行简化,计算结果显示,简化之后的模型误差为0.5%,计算时间下降了78.9%。利用两参数和四参数结构分析方法对均压环、屏蔽环的相对距离和管径、环径进行同步分析,得到带跳线和不带跳线的绝缘子串均压环、屏蔽环的最佳参数配置。计算结果显示,对于不带跳线的绝缘子串,需要配置屏蔽环的中心距增加100 mm、环径增加210 mm、管径增加10 mm,均压环的抬高距增加270 mm、环径增加40 mm,才可以达到与带跳线绝缘子串相同的屏蔽效果。研究结果表明,变电站末端门架绝缘子串需要配置更大尺寸的均压环和屏蔽环,多参数结构分析方法有效。

For the severe corona,found through ultraviolet observation,at insulator strings of the 750kV substation end portal frame,which is more severe than that in other positions,a difference analysis on the voltage equalization characteristics of different types of insulator strings is proposed.Firstly,a threedimensional model of 750kV substation is built,and the voltage equalization characteristics of insulator strings with and without jumpers are compared.The overall model is simplified by the submodel mesh and detail simplification technology.Calculation results show that the error of the simplified model is only 0.5%,and the calculation time decreases by 78.9%.Then,twoparameter and fourparameter structural analysis methods are used to synchronously analyze the relative distances,pipe diameters and ring diameters of shielding rings and grading ring.Finally,the optimal parameter configuration of the insulator string grading ring and shielding rings with and without jumpers is obtained.According to the results,to achieve the same shielding effect as insulator strings with jumpers,insulator strings without jumpers require an increase in center distance,ring diameter and pipe diameter of the shielding ring by 100mm,210mm and 10mm respectively,and an increase in the lifting distance and ring diameter of the grading ring by 270mm and 40mm,respectively.The study results indicate that the insulator strings of the substation end portal frame need to be equipped with larger grading rings and shielding rings.The structural optimization process also verifies the effectiveness of the multiparameter structural analysis method.