Control device and active filter apparatus

An active filter apparatus comprising:

• an active filter connected in parallel with a load at an installation point with respect to an AC power supply provided in a power system;
• and
• a control device for the active filter,
• wherein the control device includes
• a harmonic voltage detector to detect an m-order harmonic voltage (m is an integer not less than two) included in a voltage of the installation point,
• a phase corrector to correct a phase of the detected m-order harmonic voltage in accordance with whether an m-order harmonic impedance when an AC power supply side is seen from the installation point is capacitive or inductive,
• a command value generator to generate a first compensation command value for compensating for the m-order harmonic voltage included in the voltage of the installation point based on the m-order harmonic voltage after the correction, and
• an output controller to control an output of the active filter based on the first compensation command value,
• wherein the phase corrector does not correct the phase of the detected m-order harmonic voltage when the m-order harmonic impedance is inductive.