采用小波多分辨率能量分布分析电网过电压特征

Analysis of Characteristics of Over-voltage in Power System Using Multi-resolution Energy Distribution of Wavelet

小波多分辨率分析技术已在处理非平稳信号中表现出强大的优越性,信息熵能有效表征系统紊乱程度。为此,结合小波和信息熵理论,提出基于信号分段能量在时频空间分布的信息熵特征计算方法,为有效提取不同类型过电压特征提供了新方法。对电力系统4种过电压—合空载变压器过电压、开关操作过电压、投入电容器组过电压、感应雷过电压进行实例分析,结果表明:小波分析和信息熵的结合能够有效地提取4种过电压信号的特征信息,过电压沿小波各层能量分布和小波分段能量熵能有效作为过电压识别的特征,为展开过电压类型的诊断、识别奠定了基础。

Wavelet multi-resolution analysis technology has strong advantages for non-steady signals processing, and information entropy can effectively characterize the disturbance degree of system. We put forward a method of calculating information entropy in the time-frequency space, by combining the theory of wavelet and information entropy. The method provides a novel way for extracting over-voltage features. By analyzing four kinds of field acquired power system over-voltage-transformer energizing, circuit breaker switching operation, capacitor switching and induced lightning overTvoltages, the results show that the combination of wavelet analysis and information entropy can effectively extract the features information from the four kinds of over-voltage signals.