含有非线性电场均化层的高压套管电场分布特性

Electric Field Distribution Characteristics of High-voltage Bushing with Nonlinear Electric Field Grading Layer

直流套管是制约我国直流输变电技术发展和安全可靠运行的主要因素之一。该文提出了含有非线性电场均化层的高压套管技术路线,仿真研究了接地屏位置、长度以及非线性电场均化层几何尺寸、材料参数对高压套管电场分布的影响规律。分析表明:接地屏的位置和长度主要影响导杆表面电场值及其电场集中区域范围;电场均化层的长度、非线性参数、位置会对套管内部及表面电场分布产生显著影响;更长的电场均化层、较低的非线性材料阈值场强以及更远的电场均化层到导杆表面的距离均能有效均化套管电场。直流电场下含有非线性电场均化层的高压套管电场分布与交流电场下存在较大差异,具有高阈值场强的非线性电场均化层均场效果更优。非线性均压层能够有效改善高压套管的电场分布,无需采用电容均压结构。该工作将为非线性复合材料在高压套管中的应用提供参考。

DC bushing is one of the main factors that restrict the development and safe operation of DC power transmission and transformation technology in China. This paper presents a technical route of high-voltage(HV) bushing with nonlinear electric field grading layer. The influence of the position and length of grounding plate, geometric size and nonlinear parameters of electric field grading layer on electric field distribution of HV bushing is studied by simulation. The analysis reveals that the position and length of grounding plate mainly affect the value and concentration area of electric field on the conducting rod surface. The length, nonlinear parameters and position of electric field grading layer have significant influence on the electric field distribution inside and on the surface of the bushing. The longer electric field grading layer, lower threshold electric field of nonlinear material and longer distance from the electric field grading layer to the surface of the conducting rod will lead to a good electric field grading effect. The electric field distribution of HV bushing with nonlinear electric field grading layer under DC differs significantly from that under AC. The electric field grading layer with higher threshold electric field shows better electric field grading effect. This work shows that the nonlinear electric field grading layer will effectively grading the electric field distribution in HV bushing without capacitive electric field grading structure. It will provide reference for the application of nonlinear material in HV bushing.