Identification of Damages to Electrical Networks through the Spectral Analysis of Transient Processes

Transient processes that occur during any damage to electrical power facilities carry information about the location and nature of the damage. Specific information carriers are not only the readings of observed currents and voltages but also the spectral components of these quantities. Attention is paid to the harmonics of the fundamental frequency. However, their information content cannot be sufficient to identify the damage. Moreover, there are modes in which they are compensated or absent altogether because of the disconnection of sources. The article focuses on spectral components of the free process, which is an integral part of the transient process that accompanies any damage. Being the natural frequencies of the observed network, the complex values of the frequencies of the spectral components are the same for all observation locations of a given object. The equations of the linear model of the object are compiled for these locations on the basis of the complex method, however, based only on the own complex frequency value. The spectral analysis procedures that isolate spectral components with their complex values of frequencies and amplitudes are considered. It is demonstrated that the mode of each individual spectral component can be divided into two parts, normal and local. The ratio of local complexes of the same complex frequency value on various sides of the line is uniquely related to the location of its damage.