| 摘要 |
PURPOSE:To cope with a large fluctuation with simple constitution by giving an error signal to a proportional plus integral controller to apply the phase control and increase or decrease the count thereby allowing the count to increase/decrease the number of capacitor banks. CONSTITUTION:A difference between a system voltage and a setting voltage is operated by an adder 6, a switch 13 connected in series with a reactor is subject to phase control by using the output of the adder to compensate the reactive power. When the output of the adder 6 is large enough to exceed the limit of the phase control, that is, when the value exceeds the upper/lower limit of comparators 55,56, a counter circuit 57 is incremented/decremented in matching with a timing signal having a prescribed time interval. As a result, capacitor semiconductor switches 23,33 are applied or interrupted sequentially in response to the count so /as to cope with the fluctuation. |
