| 摘要 |
PURPOSE:To suppress the higher harmonic current more effectively by compensating the higher harmonic current by the coexistence of an LC filter and an active filter. CONSTITUTION:In an active filter AF, which is connected to a circuit provided, on a power source (e) side, with an LC filter F for control of higher harmonics, load L and an LC reactor circuit are provided with current transformers CT1 and CT2, and a signal k1 of the reverse phase from the detection signal I2 of the current transformer CT2 is added to the detection signal I1 of the current transformer CT1. Furthermore, with the sum signal I1-I2 as the detection signal of the active filter AF, the active filter AF compensates the higher harmonic current flowing from the load L to the LC filter so as to compensate the higher harmonics so that it may not prevent the absorption of the higher harmonic current by the LC filter. |
