Harmonic state space model of a closed-loop balanced Thyristor Controlled Series Compensator

Abstract

Power system engineers have always relied on the use of fixed switching instants in the analysis of FACTs devices such as for the Thyristor Controlled Series Compensator (TCSC). In reality, these switching instants vary due to voltage and current distortions. In this paper, a Harmonic State Space (HSS) model for controlled balanced three-phase TCSC is presented which captures the switching instant variation. In addition, a current-controlled model with a PI controller is presented to exhibit the HSS model's ability to incorporate controls for possible dynamic harmonic domain analysis. As an LTI-type model, applicability of traditional analysis tools such as pole zero diagrams is also presented.