Software control of the thyristor-controlled reactor improving dynamic response

Abstract

This article proposes a control method for the thyristor-controlled reactor (TCR) to improve the dynamic response using a fast detection method. The method is based on the substitution of conventional filtering by an efficient, faster and simpler process with a lower computational burden. This method shows that the compensation process performs within 1/4 cycle of the fundamental line period. Because of its fast response, the proposed method makes it possible to apply a rapid changing load such as an electric arc furnace. The proposed controller utilises feedforward and closed-loop control techniques. The feedforward control is the direct calculation of the TCR reference current to compensate for reactive power and unbalanced load. The feedforward control enhances the dynamic response of the system along with the fast detection method. Analysis and experimental results from a 3kVA prototype are presented.