Frequency domain techniques for modeling distribution or transmission networks using capacitor switching induced transients

Frequency-domain identification methods for the impedance characteristics of a power system network are presented. Two frequency-domain methods are used to obtain the impedance transfer based on the discrete Fourier transform and power spectral estimation. These impedance characteristics are then used to find equivalent network models. One is a polynomial model for the individual real and imaginary parts of the impedance transfer function. The second is an equivalent circuit model based on the system impedance poles and zeros. The methods discussed are based on the use of recorded power-system voltage and current waveforms sampled at a high sampling rate during transient conditions due to capacitor-switching operations. Actual recorded data from a 12 kV distribution system are used