| 摘要 |
PURPOSE:To minimize the voltage variation width of an automatic voltage controller by always counting the tap action frequency of a tap switch transformer in a load mode every fixed period to compare this counted frequency with the maximum tap action frequency and varying the set value of a blind sector according to the result of said comparison. CONSTITUTION:The set signals are supplied to an automatic voltage controller 5 from an initial blind sector setter 6, a maximum allowance blind sector setter 7, a maximum tap action frequency (Nmax) setter 9, a minimum tap action frequency (Nmin) setter 10, etc. Thus a tap switch transformer 2 of load mode gives automatic control to the system voltage. In case the actual tap action frequency N exceeds the frequency Nmax of a certain period obtained from the tap action lifetime of the transformer 2, the set value of blind sector of the controller 5 is automatically increased. Thus the tap action frequency N is set at the proper value. When the actual frequency N is smaller than the frequency Nmin, the set value of blind sector is reduced automatically. Thus the variation of the system voltage is reduced. |
