Analysis of the Conducted Interfering Mechanism within SVC-based substations

In this paper, a simulation model is established to investigate on the conducted mechanism in substations installed with SVC (Static Var Compensator) devices with a view to characterizing the main causes of the conducted interference. The high-frequency macro model for thyristors is established with a nonlinear time-varying resistor to simulate the switching characteristics of the thyristors. Based on the above macro model for thyristors, a concrete model of SVC including TSC (Thyristor-switched Capacitor) and TCR (Thyristor-controlled Reactor) is further proposed. In addition, high-frequency equivalent models for frequency-domain compensation of both CT and PT, based on their calibrated non-flat amplitude-frequency characteristics, are adopted to rectify the emissions levels from the SVC switching. The conducted interferences by simulations are correlated with that from on-site measurements, which indicates that the high-frequency switching characteristics of thyristors are the main causes of conducted emissions.