| 摘要 |
PURPOSE:To reduce power consumption while prolonging the replacing interval of components having finite life by subjecting an active filter unit to operation of stop control according to the content of harmonics in the current or voltage of an object, i.e., a load system, being compensated for the harmonics. CONSTITUTION:The content of higher harmonics in the current or voltage of a feeder bus integrating the load system is detected by a system current detecting circuit 11 or a system voltage detecting circuit 12. The detected value of each harmonic is compared, at a harmonic content comparing circuit 13, with an upper limit value set by a harmonic content setting circuit 14. A selection circuit 15 delivers a command signal SOP, when the upper limit value is exceeded, otherwise a command signal SST, to an active filter unit which is thereby operated or stopped in automatic mode or manual mode depending on the content of harmonic. |
