基于电阻频响法的绕组材质无损检测技术研究

近年来随着双金属复合材料技术的发展,铜铝复合材料在一些电力设备中得到广泛应用,但也有些部分厂家"以铝充铜",使得导体材质无法确定,给设备的运行维护工作带来困难。因此,亟需一种导体材质快速无损检测方法,这对电力设备材质辨别和运行维护具有重要的工程意义。文中基于电磁场理论,建立了铜包铝导体交流电阻数学模型,仿真分析了交流电阻随频率的变化规律,并对不同频率电阻进行归一化处理,发现不同铜含量的铜包铝线的电阻变化率存在转折点,通过对比分析其转折频率,可以实现不同材质绕组的无损鉴别。在此基础上,绕制不同材质的测试绕组,对仿真模型进行了实验研究,验证了基于电阻频响法的绕组材质无损检测技术的可行性。

Research on nondestructive testing method of winding material based on resistance frequency response method

With the development of bimetal composite technology, copper-aluminum composites have shown certain advantages in many aspects. Therefore, this material has been used in various electric power equipment, such as wires and cables, transformers, and power distribution cabinets. However, some manufacturers replace copper by this alloy but do not inform the customer, which makes it difficult to operate and maintain the equipment. Therefore, there is a need for a rapid non-destructive testing method for conductor materials. Based on the theory of electromagnetic field, this paper establishes a mathematical model of AC resistance of copper-clad aluminum conductor. The variation AC resistance with frequency is simulated. With normalization of resistance under different frequency, we see that the resistance variation is different with different copper content. There is a corner point in the frequency responses. By comparing and analyzing the corner frequency, the non-destructive identification of windings with different materials can be realized. Then, the paper carries out experimental test based on the simulation model, which confirms the feasibility of the non-destructive testing technology of winding materials based on the resistance frequency response method.