Contents I. Introduction
In recent times there has been significant interest in the wideband measurement of power system impedances [1]–[4]. With the increasing prevalence of nonlinear harmonic-producing loads and high-switching-frequency power electronics converters, the power distribution system is becoming a wideband network. Knowledge of harmonic generating and high-frequency impedances is necessary for prediction of resonances, harmonic propagation and voltage distortion at various locations on the power network, and identification of harmonic polluters. Moreover, it can improve the effectiveness and stability of active filters, in particular if the impedance can be measured in real time at the active filter location. Additionally, it allows the detection of high-impedance ground faults and of slight system imbalance over wide frequencies, potentially exceeding the capability of Phasor Measurement Units, which require harmonic content to already exist in the system.
