一种基于相对比较法测量容性设备介质损耗的滤波算法

摘要

为了更准确地求得容性设备的介质损耗因素(tanδ),提高相对比较法的抗干扰能力,提出一种基于相对比较法的滤波算法.利用相关函数的滤波性,通过将选取的两设备泄漏电流分别与标准基波相关,对泄漏电流先进行滤波处理,然后再利用互相关函数的时延特性求得设备介质损耗,从而使得算法更加精确.算例分析结果表明,该方法正确,抗干扰能力更强,具有较高的精度.在谐波干扰一定的情况下不断增加环境干扰,即使在信噪比低至5 dB的情况下也能正确运行,有一定的实际应用价值.%In order to improve anti-interference ability of relative comparison method and more accurately calculate dielectric loss factor (tanδ) of capacitive devices, a kind of filtering algorithm based on relative comparison method is put forward, through correlating the leakage current with the standard fundamental harmonic and using the filter characteristics of cross-correlation function, so that the algorithm is more accurate. Simulation results show that the method is correct, which has a stronger anti-interference ability and higher accuracy. With the increased environmental interference under circumstance of certain harmonic interference, even in case of 5dB SNR, it could run correctly as well. There are certain practical values.