| 摘要 |
PURPOSE:To obtain stable control characteristic and to prevent an increase in a harmonic current by detecting a current obtained by subtracting a current flowing to a capacitive load from a load current, and transmitting the same compensating current as the harmonic current component of the current to a system. CONSTITUTION:A load 2 to be compensated is formed of a harmonic wave source 3 for generating a harmonic wave such as an inverter, and a capacitive load 4 such as a phase advancing capacitor, etc. An active filter 6 outputs the same compensating current Ic as the harmonic current component of a load current Il based on the output of a current transformer 5. A current If flowing to the load 4 is detected by a current transformer 7, and sent to the filter 6 through a calculator 8. The filter 6 outputs a compensating current Ic with the harmonic current component of this differential current I* as a control target value. The current If of the load 4 is removed by the filter 6 to prevent a positive feedback, and stable control characteristic is obtained. |
