应用TC方法的电压暂降检测

Detecting voltage sag using method of TC

针对电能质量故障中电压暂降故障的诊断,提出容差曲线法.基于传统的电压暂降特征量的方法没有充分考虑到电压容差,因而可能造成检测误差较大.所提出的新方法利用了电能质量监测参数(Vsag,Vavg,d)和容差曲线的电压最小值Vmin.在容差曲线方法的公式中,能够用k次均方根的函数表示接近于矩形的电压暂降波形,且可以通过改变函数中的某些量来改变电压暂降持续时间.研究结果表明:该方法不仅能够应用在矩形暂降波形的的电压暂降故障检测中,还可以应用在非矩形暂降波形的电压暂降故障检测中.

This paper proposes a new method that is tolerance curve method for the diagnosis of voltage sag fault, which is belongs to power quality fault. The method is based on the traditional voltage sag characteristics which does not consider the characteristics of voltage tolerance fully, thus it may cause worse error in the process of detecting. The proposed method utilizes the monitored parameters（Vsag,Vavg,d） of PQ and the minimum voltage Vmin of voltage tolerance curve. The voltage sag profile is approximated by using the kth order radical root function, and the sag duration can be modified by changing some variable in the function. The research results indicate that the proposed method can be applied to detect the nonrectangular sag so as the rectangular sag.