| 摘要 |
PURPOSE:To inhibit the tap switching with the sudden load fluctuation at the secondary side of a transformer or the flicker voltage, by using a means which absorbs the fluctuation of the voltage at the primary side of the transformer for tape switching in a load mode. CONSTITUTION:The primary voltage of a transformer 2 for tap switching in a load mode which is supplied to an automatic voltage controller 5 is sampled in a fixed cycle. Thus the mean value of said primary voltage is obtained for t1sec. Then the difference DELTAV is obtained between said mean voltage value and the voltage corresponding to the position of the tap delivered from a voltage generator 9. This difference DELTAV is compared with the blind sector set value DELTAV1 set previously. If DELTAV1<DELTAV is satisfied, this difference is used as the integration data for replacement of the integration value. Then this integration value is compared with the operation set value. If the integration value is larger than the operating set value, it is decided for the first time that the tap switching is needed for the transformer 2. Then a 1-tap switch command is delivered and at the same time the integration value is cleaned. |
