ABSTRACT
Linear plant components respond to a sinusoidal input with a sinusoidal output, while the response of a nonlinear plant component is a distorted waveform. This chapter aims to detail in suitable models of power plant components with which to carry out the kinds of studies. It presents a popular tool used in the study of unbalanced systems—the long-enduring symmetrical components. In a three-phase supply system, the three sinusoidal waveforms should have equal amplitudes and their phase angles be phase-shifted by 120 electrical degrees from each other; a condition that is amenable to a perfect quality of supply. The analysis of an unbalanced grid is usually made by decomposing the unbalanced system into three balanced systems exhibiting positive, negative, and homopolar sequence. The computation of three-phase transmission line parameters becomes cumbersome by the existence of inductive and capacitive couplings between conductors, and between conductors and ground.
