特高压盆式绝缘子水压试验中应力应变分布的仿真计算与光纤测量

Calculation and Experimental Study on Strain and Stress Distribution of UHV GIS Spacer During Hydrostatic Test

特高压盆式绝缘子是气体绝缘开关设备的关键部件,绝缘子的应力集中可能会导致盆式绝缘子内部产生微裂,引发放电事故并对盆式绝缘子产生更严重的破坏。为了分析特高压盆式绝缘子在受到外力作用下应力应变分布情况,采用有限元软件ANSYS对盆式绝缘子在水压试验中应力应变的分布情况进行仿真计算,基于计算结果,将布拉格光栅光纤布置于盆式绝缘子表面,测量盆式绝缘子在水压破坏试验中不同位置应变大小并与仿真计算结果相比较。结果表明,盆式绝缘子在水压试验中应力最大的位置位于靠近法兰曲率半径较小的盆面处,该位置也是盆式绝缘子破坏时的破坏起始位置。仿真计算所得盆式绝缘子的应力应变与实际测量结果一致性较好,是一种对盆式绝缘子应力分析研究的有效可靠方法。

UHV GIS spacer is a key insulator in the gas insulated switchgear, the concentration of stress may cause tiny flaws on the spacer which will lead to discharge on the spacer. In order to analyze the stress concentration on the GIS spacer when external stress acts, the ANSYS is applied to calculate the distribution of the stress and strain during the hydrostatic test. At the same time, the fiber Bragg grating is arranged on the surface of the GIS spacer based on the calculation to measure the strain of different positions in hydrostatic test. The results of measurement and calculation indicate that the worst stress concentration lies near the flange where the spacer has a small radius of curvature, and the cracking begins here. The experiment shows a similar result on the strain distribution with the calculation, which verifies that the calculation is an effective method to study the mechanical of GIS spacer.