CONTROLLER FOR REACTIVE POWER COMPENSATOR

PROBLEM TO BE SOLVED: To increase transmission power by trying to generate reactive power equivalent to reactive power generated during passage of system load current detecting a virtual serial reactance and to reduce the reactance of transmission line, by determining an output target value of a reactive power compensator, thereby providing a surplus power for system accidents. SOLUTION: A current transformer 12 is installed to a power system 1 for detecting a system load current, and a controller 6a for determining the output target of a reactive power compensator is added so as to generate a reactive power equivalent to that which occurs when the system load current passes a virtual serial capacitor. This output target determines the ignition angle of thyristor 4 in an ignition angle determining circuit. When voltage phase coincides with the ignition angle in a voltage phase detection circuit, the ignition pulse is outputted to the thyristor 4 by an ignition pulse generating circuit, and then ignition occurs and the reactor 3 is phase-controlled. Thus, the transmission limit increases and the control becomes possible in response to the system load current.