CONTROL DEVICE AND ACTIVE FILTER DEVICE

A control device (100) for an active filter (80) connected in parallel with a load (4b) at an installation point (4a) with respect to an AC power supply (2) provided in a power system includes a harmonic voltage detector (7) to detect an m-order harmonic voltage (m is an integer not less than two) included in a voltage of the installation point (4a), a phase corrector (9) 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 (2) side is seen from the installation point (4a) is capacitive or inductive, a command value generator (10) to generate a first compensation command value for compensating for the m-order harmonic voltage included in the voltage of the installation point (4a) based on the m-order harmonic voltage after the correction, and an output controller (18) to control an output of the active filter (80) based on a first compensation command value.