基于小波变换的短路故障早期检测门限值的研究

当采用小波分解方法对低压配电系统短路故障进行早期检测时,门限值的合理设置对故障检测的可靠性及灵敏度是至关重要的.本文通过对低压配电系统电动机的起动、过载及线路短路的暂态过程进行深入研究,得到了基于三次B样条小波变换的短路故障早期检测门限值的设置方法.该方法与全波傅里叶模值检测方法相比,不仅可将短路故障与电动机起动、过载正确区分开,而且还可超高速地检测出短路故障.仿真结果证实了该方法的正确性及有效性.

Research on Threshold of Early Prediction for Short Circuit Fault Based on Wavelet Transform

The proper setting of threshold is crucial for the early prediction of the short circuit fault in the low-voltage distributed system when using the method of wavelet decomposition. The approach of threshold setting for the short circuit fault early detection based on quadratic B spline wavelet has been discussed in this paper by researching on the transient process of motor starting, overload and short circuit faults in low-voltage system. Compared with the Full-wave Fourier Module method, this approach can distinguish the different types of fault and detect the fault quickly. The validity of this method has been verified by simulating results.