Control of the Thyristor-controlled Reactor for Reactive Power Compensation and Load Balancing

This paper 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 guarantees that the compensation process will perform within 1/4 cycle of the fundamental line period. Due to its fast response, the proposed method makes it possible to apply a rapid changing load such as an electric arc furnaces. The proposed controller utilities feed forward and closed loop control techniques. The feed forward control is the direct calculation of the TCR reference current to compensation for reactive power and unbalanced load. The feed forward control enhances the dynamic response of the system along with the fast detection method. Analysis and experimental results from a 3 kVA prototype are presented.