| 摘要 |
PURPOSE:To improve the power factor of a power source by providing an input transformer between a power source and a thyristor type phase controlling circuit and cooperating the tap voltage change with the output frequency of an inverter. CONSTITUTION:A bidirectional electric valve 80 is provided between a 3-phase AC power source 1 and a thyristor type phase controlling circuit 10, and a controller 6 therefor is further provided. Taps are provided at the secondary side of a transformer 60, and bidirectional electric valves 82, 92, 72 are connected between the taps and a thyristor type phase controlling circuit 10. Bidirectional electric valves 81, 91, 71 are also connected between one terminal of the secondary side and the controlling circuit 10. A phase controller 2 is controlled so that the DC output voltage becomes the desired value, and the controller 80 of the valve 80 controls the valve 80 to meet the output frequency of an inverter main circuit 50 in cooperation with an inverter controller 3. |
