| 摘要 |
PURPOSE: To reduce a harmonic current in a capacitor circuit, by connecting an active filter in parallel with the power-factor improvement circuit with a capacitor and a reactor, detecting a resultant current in these circuits, and calculating a current command value for each active filter from an integrated value of the resultant current. CONSTITUTION: An active filter 5 is connected in parallel with a power-factor improvement circuit including a capacitor 41 and a a series reactor 42 in the power distribution system. A current detector 61 detects a resultant current made up of a current in the active filter 5 and a current in the capacitor circuit including the capacitor 41. The resultant current is inputted to the active filter 5 through a load resistor 62. In addition, a compensation current command is obtained by calculating only a harmonic factor on the basis of an output of an integration circuit 57. As a result, a harmonic current into the power- factor improvement circuit with the capacitor 41 and reactor 42 in series can be reduced even when an voltage includes harmonics in power system, and the enlargement of resonance can be prevented. |
