| 摘要 |
PURPOSE:To alleviate the voltage drop at an AC motor starting time by previously altering the tap of a transformer with an on-load tap changer and then separating an on-load tap changer drive unit. CONSTITUTION:When a closure signal is applied to a motor, a starting contact 11 is closed, an on-load tap changer drive unit 7 is operated to rise the output voltage of a transformer 2. The output voltage of the transformer 2 at this time is controlled to the set value or lower by a contact 14. On the other hand, a coil 12 is operated simultaneously with the closure of the contact 11, a switching unit 5 is closed to start an AC motor 4. When the motor 4 is started, the voltage value of the output circuit of the transformer 2 is already raised. Accordingly, the voltage drop is alleviated. When the unit 5 is closed, the contact 13 is opened, and the drive unit 7 is thereafter operated by the output contact 6 of an automatic voltage regulator 3. |
