| 摘要 |
PURPOSE:To suppress suitably the voltage variance at an AC/DC connection point when the operation state of a DC system is changed suddenly, by increasing or reducing the reactive power at the AC/DC connection point in accordance with a DC current of a DC power transmission system or a phase control angle of an AC/DC converter. CONSTITUTION:The controlling system for making the voltage constant at the AC/DC connection point is provided with a reactive power correcting circuit 13 where a DC current Id and an angle alpha of delay obtained through a DC current detecting circuit 12 are inputted to correct a reactive power control signal (q) with a closed loop. In this case, a reactive power correcting system is a closed loop, and it is unnecessary to give a time delay element to the circuit 13; and therefore, when the operation state of the DC system is changed suddenly and the current Id or the angle alpha of delay is changed, the circuit 13 is operated without a time delay to change the reactive power correcting signal q2, and the reactive power control signal (q) obtaines as the sum of a reactive power control signal q1 and the reactive power correcting signal q2 is changed. Thus, the voltage variance at the AC/DC connection point is suppressed effectively. |
