Abstract

The capabilities of the X-ray method of nondestructive testing of high-voltage oil-filled equipment are investigated using the example of a low-oil switch of the VMT series of 110-kV voltage class (VMT-110) with porcelain external insulation. A list of characteristic types of defects based on the analysis of the causes of failure of VMT-110 switches was compiled, and a special defective sample (SDS) for laboratory research was created. The following types of defects were simulated: contact bar deformation, contact wear, burning of the contact surface and reducing the height of the contact part of the movable contact, cracks in the casing of the fixed contact, crimping failure and rope unwinding, mechanical damage to the bottom rollers, fracture of the upper roller spring, bearing defects, cracks in the insulating rods of the control system of the movable contact, and cracks on the inner and outer surfaces of the porcelain insulator of the arcing chamber. The X‑ray examination of SDS was performed using a monoblock X-ray device with a constant voltage on the tube and directed radiation output. The optimal parameters of the X-ray device were selected experimentally. The information content of the SDS radiographs for monitoring the SDS technical condition was evaluated by comparing the actual defects with the images obtained on the radiographs. The results of the SDS study have shown that the proposed technical solution can detect at least 75% of the characteristic types of defects in the internal structural elements of the VMT-110 switch. The proposed instrumentation can be used to monitor the technical condition of other types of high-voltage equipment (gas-insulated switches, gas-insulated switchgear, measuring transformers, and cable couplings) onsite without disassembly.

中文翻译：

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X射线控制高压低油开关技术条件的可能性的研究

摘要

以带有瓷器外部绝缘的110 kV电压等级VMT系列（VMT-110）的低油开关为例，研究了高压注油设备的X射线法无损检测能力。根据对VMT-110开关故障原因的分析，列出了缺陷的特征类型列表，并创建了用于实验室研究的特殊缺陷样品（SDS）。模拟了以下类型的缺陷：接触杆变形，接触磨损，接触表面烧伤并降低了活动触点的接触部分的高度，固定触点的外壳出现裂纹，压接故障和绳索解绕，机械损坏到下罗拉，上罗拉弹簧断裂，轴承缺陷，动触头控制系统的绝缘棒上有裂纹，而电弧室烤瓷绝缘子的内表面和外表面也有裂纹。使用整体式X射线设备对SDS进行X射线检查，该设备在管上具有恒定的电压，并具有定向辐射输出。通过实验选择了X射线设备的最佳参数。通过将实际缺陷与射线照片上获得的图像进行比较，评估了用于监视SDS技术条件的SDS射线照片的信息内容。SDS研究的结果表明，所提出的技术解决方案可以检测出VMT-110开关内部结构元件中至少75％的特征类型缺陷。