基于改进波形匹配法的变压器局放超声直达波分离研究

Separation Research of Ultrasonic Wave in Transformer Partial Discharge Based on Improved Waveform Matching

变压器局放超声阵列定位中,利用直达波进行定位能够更好地提高局放源的定位精度。针对超声传感器接收到的信号是直达波和非直达波以及各种噪声的混合叠加,提出了基于改进波形匹配法的变压器局放超声直达波分离方法。该方法认为传感器最先接收到的信号为直达波信号,通过三个最值点构建基准三角形,计算衰减系数以及信号频率,然后根据上述参数对基准三角形进行平移、缩放,求得匹配波形,最后在众多的匹配波形中选择匹配程度最高的作为直达波信号,仿真结果表明该方法能够从超声传感器接收到的信号中分离出超声直达波信号,为提高局放源的定位精度提供了一定的理论指导。

The use of direct wave to locate the position of the PD source is of better accuracy in transformer partial discharge ultrasound array positioning. A direct wave separation method based on improved waveform matching is proposed in this paper, for the signal received by ultrasonic sensor is consisted by direct wave,non-direct wave and a variety of noise. It is considered that the direct wave first reached is the ultrasonic sensor. As a benchmark triangle is built, the attenuation coefficient and the signal frequency, then, are both calculated. In order to search the matching wave, the benehmarktriangle is to pan and zoom. Finally, the best matching waveform is selected from a large number of matching waveforms as a direct wave signal. The result of simulation shows that the method can isolate the ultrasonic direct wave signal from the received signal, which provides some theoretical guidance to improve the positioning accuracy of the PD source.