Patent ID: 7683589

Claim:
A reactive power compensator having a static var compensator that generates reactive power corresponding to a voltage fluctuation of a connection bus, wherein the reactive power compensator suppresses voltage fluctuation of a first controlled bus laid near the static var compensator and suppresses voltage fluctuation of a second controlled bus laid at a distance from the static var compensator, the reactive power compensator comprising: a comparison-voltage producing unit that produces a comparison voltage following a first controlled voltage, which is a bus voltage of the first controlled bus, with a predetermined time delay characteristic and restricted to a predetermined range; a fluctuating-voltage producing unit that produces a fluctuating voltage being a differential output between the comparison voltage and the first controlled voltage; a reactive power controller that controls the reactive power generated by the static var compensator to be controlled corresponding to the fluctuating voltage with a time characteristic faster than the time delay characteristic of the comparison voltage; a reactive-power initial-value changing signal producing unit that produces a reactive-power initial-value changing signal that is a signal indicative of whether a second controlled voltage, which is a bus voltage of the second controlled bus, has deviated from a predetermined range follow with a predetermined time delay characteristic; and a reactive power adjusting unit that sets the reactive power produced by the static var compensator to a predetermined value, based on the reactive power produced by the static var compensator, the comparison voltage produced by the comparison-voltage producing unit, and a predetermined initial value, the reactive power adjusting unit controlling the second controlled voltage so as to fall within the predetermined range when the second controlled voltage has deviated from the predetermined range.