基于小波变换的电力变压器保护技术

A Reliable Setting-free Technique for Power Transformer Protection Based on Wavelet Transform

提出了一种新的变压器保护方法,该方法基于对离散小波变换(DWT)细节系数(DetC)的分析和监测,对内部故障条件进行识别判定。该方法提取故障特征并通过DWT分解计算DetC信号电压变化以识别变压器工况的瞬变,在内部故障期间,DetC信号与其他瞬变中的状态不同。该方法能正确识别电力变压器中不同类型的内部故障,具有在电力变压器保护中实际应用的潜力。

In this paper,a novel transformer protection method was proposed,which was based on the analysis and monitoring of discrete wavelet transform(DWT)detail coefficients(DetC)for internal fault condition identification and determination.The method extracted the fault feature and calculates the DetC signal voltage change by DWT decomposition to identify the transient of the transformer operating condition.During an internal fault,the DetC signal was different from the state that occurs in other transients.The method proposed in this paper was able to correctly identify different types of internal faults in power transformers.The results showed that the method had practical application potential in power transformer protection.