145 kV交流接地开关数值分析及振动台试验

Numerical analysis and shaking table test on 145 kV AC earthing switch

为研究145 kV高压交流接地开关在地震波作用下的抗震性能,文中对其三维模型进行模态分析,确定了接地开关的自振频率及振型,并研究发现:设备顶部接线端子在不同结构型式及重量下,三相联动结构的底座部分应力分布存在差异,试验时需合理设置采样点。通过输入生成的标准时程波进行动力学分析,确定了关键部位的应力及设备顶端最大位移。结果表明:地震动峰值加速度为0.5 g工况下,瓷支柱绝缘子的最大应变位于最下方伞裙根部,该部位为接地开关设备的易损部位,其最大应力为18.98 MPa,小于破坏应力;设备顶端接线板相对于振动台台面在X方向的位移最大为39.43 mm,由于变形较小,在进行电站的设计时可以忽略位移对相邻电力设备的牵拉作用带来的影响。对145 kV高压交流接地开关的全尺寸振动台试验结果表明,数值仿真与试验结果基本吻合,且试验发现:随高度增加放大系数逐渐增加但顶端增加显著,应变在不同工况、不同方向具有差异性,接地开关地震响应复杂且呈现非线性特性。文中进一步对通过振动台试验的设备进行测试,验证了设备的机械性能在振动台试验中不受影响。

To research the seismic performance of 145 kV high voltage AC earthing switch under the action of seismic wave,modal analysis are carried out on the three-dimensional model to determine the natural vibration frequency and mode of the earthing switch.And it is further found that the stress distribution of the base part of the three-phase linkage structure is different under different structural types and weights of the terminal block on the top of the equipment.Thus the sampling points should be set reasonably during the test.By inputting the generated standard time history wave for dynamic analysis,the stress at the key parts and the maximum displacement at the top of the equipment are determined.The results show that the maximum strain of the porcelain post insulator under the action of 0.5 g seismic wave is located at the root of the lowest umbrella skirt,which is the vulnerable part of the earthing switch,and its maximum stress is 18.98 MPa,less than the failure stress.The maximum displacement of the terminal block at the top of the equipment relative to the vibrating table in the X direction is 39.43 mm.The influence of displacement on the traction effect of adjacent power equipment can be ignored in the design of the power station.The full-scale shaking table test results of 145 kV high-voltage AC earthing switch show that the numerical simulation is basically consistent with the test results.And it is found that the amplification factor increases gradually with the increase of height,but the top increases significantly.The strain varies in different working conditions and directions.The seismic response of grounding switch is complex and nonlinear.This paper further tests the equipment that has passed the shaking table test,and verifies that the mechanical performance of the equipment is not affected in the shaking table test.