| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce harmonics by avoiding limitations due to operating frequency and increase in voltage drop due to reactance. <P>SOLUTION: A first coil 21 is inserted between an AC power supply 1 and a VVVF inverter 3, and a second coil 22, which is magnetically coupled to the first coil 21 is inserted between the AC power supply 1 and a second load 5. A second power converter 25 is connected to a third coil 23, which is magnetically coupled to the first coil 21 and the second coil 22. The second power converter 25 is so controlled that a control circuit 30 zeroes the fundamental wave voltage component that occurs with any one of the first to third coils 21, 22, and 23. Alternately, a fourth coil 24 coupled magnetically to the first coil 21, the second coil 22, and the third coil 23, is provided. The second power converter 25 is so controlled that the control circuit 30 zeroes the fundamental wave voltage component that is generated with the fourth coil 24. The first coil 21 and the second coil 22 are coupled magnetically together with polarities which mutually cancel the generated magnetic flux. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
