复合绝缘子交界面缺陷及脉冲热流远场无损检测研究

Interface Defects and Far-field Pulse Heat Flux NDTMethod for Composite Insulators

现有工程经验表明,复合绝缘子的交界面缺陷是导致复合绝缘子发热乃至异常断裂的关键因素,针对复合绝缘子交界面缺陷无损检测方法的研究具有重要科学意义与工程价值。本文首先对交界面故障情况、机理以及现有的交界面检测方法进行了综述,然后建立了一维数值模型及三维仿真模型,研究了脉冲热流在多层材料中的传播过程。研究结果表明,在对数坐标下对辐射量进行求导运算,有无缺陷区域的辐射量变化率差异相比之前将增大7倍。文章以此为基础提出了一种基于脉冲热流的远场无损检测方法。该方法检测距离超过30 cm,无需对绝缘子逐点测试,测试速度快,同时检测精度可达1 mm。

Existing engineering experience shows that the interface defect of composite insulators are the key factors leading to the heating and abnormal fracture of composite insulators. The research of NDT method for interface defect of composite insulators has important scientific significance and engineering value. Firstly, this manuscript reviews the situation, mechanism of interface defect and existing interface detection methods. Then one-dimensional numerical model and three-dimensional simulation model are established and the propagation of pulse heat flow in multilayer materials is studied. The derivate of the data has been further processed in the Logarithmic coordinate system, and the difference between defective area and reference area has approximately enlarged 7 times. Based on that, a far-field NDT method based on pulse heat flux is proposed. The measuring distance of this method is more than 30 cm, and it does not need to test the insulator point by point. The precision of this method can reach 1 mm.