Continuous regulation of capacitive reactive power

This paper presents a new method for the continuous regulation of reactive power generated by a capacitor bank. The two proposed control circuits consist of capacitor banks controlled by bi-directional switches which are built with anti-paraltel connected thyristor and GTO valves, or with two GTO valves. The current of the capacitor is regulated by turning off the GTO switch before zero current crossing. By turning off the current, charge is trapped in the capacitor, resulting in a constant capacitor voltage. To avoid the current surge, the switch is turned on when the supply and capacitor voltage are equal. The current regulation is achieved by switching off the current for a part of each cycle. The feasibility of the method has been verified by extensive transient analysis. The advantage of the proposed system is the fast and continuous regulation of reactive power without inductance. The system can be built with commercially available components and used for voltage support, power factor correction, etc.