| 摘要 |
PURPOSE:To reduce required capacity considerably and to reduce the cost by feeding fundamental wave voltage component through the ternary side of a three winding transformer for load to an active filter and producing only a corrected fundamental wave voltage and a higher harmonic compensated voltage. CONSTITUTION:A bus 6 is arranged through the secondary of a three winding transformer 5 connected with a power source 4 and an L-C filter group 2, tuned with 3rd and 5th higher harmonics, is connected with a higher harmonic generating load 1 connected with the bus 6. A voltage V0 is fed from the power source 4 through the ternary side of the transformer 5 to an inverter 12 where a required Vn is lapped over the voltage V0 through a coupling transformer 8, thus carrying out coupling with a system bus 6. Second higher harmonic is taken out through a higher harmonic current detector 10, and a control circuit 11 performs power conduction control of the elements in the inverter 12 through a comparator thus producing a voltage for canceling the higher harmonic current. By such arrangement, abnormality such as lower harmonic counter resonance can be suppressed through an inexpensive arrangement. |
