特高压GIS断路器绝缘拉杆残余应力检测技术

Residual Stress Detection Technology for Insulation Pull Rod of Extra-high Voltage GIS Circuit Breaker

  • 摘要: 纤维增强环氧树脂绝缘拉杆是气体绝缘金属封闭开关设备(Gas insulated switchgear,GIS)断路器中机械传动与电气绝缘关键部件,但因固化收缩等因素会在其内部产生残余应力,在开断载荷叠加作用下容易引发纤维-树脂界面损伤,继而引起机械故障或绝缘击穿故障。目前缺少有效的无损检测技术,导致绝缘拉杆带病入网。基于声弹性效应提出了残余应力检测技术,采用双轴同步滑台与旋转单元联合控制建立了绝缘拉杆自动检测平台,并通过真型试验验证了残余应力对绝缘拉杆极限载荷的影响规律。结果表明,自动检测平台可以对特高压GIS断路器绝缘拉杆任意位点残余应力的自动检测与差值成像,并利用残余应力归一化对绝缘拉杆残余应力诱发机械故障的风险进行了分级,最后试验验证了绝缘拉杆残余应力幅值与集中位置和其破坏载荷及破坏位置具有一致性。研究结果对改进绝缘拉杆制作工艺、提升绝缘拉杆入网检测能力具有重要意义。

     

    Abstract: Fiber reinforced epoxy resin insulation pull rod is a key component for mechanical transmission and electrical insulation in gas insulated switchgear(GIS) circuit breakers. However, residual stress will be generated inside due to curing shrinkage and other factors, which can easily cause damage to the fiber-resin interface under the superposition of breaking loads, leading to mechanical failure or insulation breakdown. Currently, there is a lack of effective non-destructive detection technology, resulting in operating with defects. A residual stress detection technology based on the acoustic-elastic effect is proposed. A dual axis synchronous sliding table and a rotating unit are introduced to establish an automatic detection platform for insulation pull rods. The influence of residual stress on the ultimate load of insulation pull rods is verified through real type experiments. The results show that the automatic detection platform can automatically detect and image the residual stress of the insulation rod of the ultra-high voltage GIS circuit breaker. The risk of mechanical failure induced by residual stress of the insulation rod is classified by residual stress normalization. Finally, the experimental results verify that the amplitude and concentration position of residual stress of the insulation pull rod are consistent with its ultimate load and failure position. The research is of great significance for improving the manufacturing process and enhancing the detection capability of insulation pull rods.

     

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