摘要
目前,离散小波变换在故障行波测距中广泛实际运用,其中测距算法中两个关键因素故障行波到达时间和故障行波波速的精度还可以提高。这是因为离散小波的尺度因子为2的指数,小波分解后的频带较宽。针对这个问题,提出对故障行波使用连续小波变换并从中采取合适尺度因子的方法。该方法用最小二乘法从连续小波变换后的时频信号中选取合适的尺度因子,然后在该尺度因子的时频图中测定故障行波到达时间和故障行波波速,最后计算出故障距离。仿真结果证明了此方法在单端法故障测距的准确性。
At present, the discrete wavelet transform has been widely and practical used in wave fault location. In fact, two key factors ranging algorithm about accuracy of fault traveling wave arrival time and fault wavelet velocity can also be improved. This is because the scale factor for discrete wavelet is index 2, and the frequency band is wide after wavelet decomposition. To address this issue, this paper presents a method which using continuous wavelet transform and adopting appropriate scale factor from the transformation. This method using the least square method （LSM） in time-frequency signal which comes from the continuous wavelet transform to select a appropriate scale factor, then using the scale factor in time-frequency to determine the arrival time of fault traveling and the velocity of fault traveling wave. Finally, the fault distance is calculated. Simulation results show that this method is accurate in single-ended fault location method.
出处
《电测与仪表》
北大核心
2016年第2期40-44,共5页
Electrical Measurement & Instrumentation
基金
国家自然科学基金资助项目(51467004)
