| 摘要 |
PURPOSE:To always control stable voltage by connecting a filter circuit for resonating at least with fifth harmonic voltage of fifth and seventh harmonic waves to a motor main circuit when power is fed by a non-utility generation power source. CONSTITUTION:A motor main circuit is composed of thyristors 7-12 provided through contactors 4, 5 between a 3-phase induction motor 3, a 3-phase AC power source 1 and 3-phase AC non-utility generation power source 2. The motor 3 is controlled normally with the voltage of the power source 1 and with the phase control by the voltage of the power source 2 via the thyristors 7-12 when the power source 1 is interrupted. Filter circuits F5, F7 resonating with fifth and seventh harmonic waves are connected to the motor main circuit only when the voltage of the power source 2 is controlled. |
