In a control system for a static var compensator that performs phase
control of a current of a reactor for each phase by a thyristor and thus
controls reactive power, a detecting unit that detects a tertiary
harmonic current flowing through each phase of the static var compensator
is provided, and on the basis of the tertiary harmonic current flowing
through each phase detected by the detecting unit, the thyristor of each
phase is controlled so that the quantity of generated tertiary harmonic
current of each phase becomes equal, and therefore an outflow of the
tertiary harmonic current toward a system can be restrained by an
inexpensive method.