Equivalent Generators as Fault Indicators in the Observed Power Facility Model

The passive model of the observed power facility is presented as an equivalent generator with respect to an unknown fault location. The voltage or current observed in each of the surveillance locations serves as an external source of the model. The equivalent generator is characterized by one of two pairs of typical modes. The first pair is formed by the idle mode and the reaction mode (named a local mode) of the passive model in response to the applied unknown load current of the equivalent generator. The second pair is made up of the solid fault mode and the reaction mode (named a quasi-local mode) in response to the applied voltage of the same load. The information properties of the local and quasi-local modes are identical and reflect the fact that the ratios between the images of the local (quasi-local) components of different surveillance locations produce a one-to-one correlation with the fault location coordinate regardless of the external links of the object. An example is the frequency response of such correlation in a uniform long-distance transmission line. The application of the finite Fourier transform at the free-process frequency in a feeder with an isolated neutral is considered.