| 摘要 |
PROBLEM TO BE SOLVED: To control the capacitiveness and inductiveness of a thyristor- controlled series capacitor at a high speed by calculating the impedance of the capacitor in accordance with an operation command value from the outside and by judging whether the impedance to be used is capacitive or inductive. SOLUTION: In order to compensate the reactance 31 of an AC transmission line 30 connecting an AC system 10 with a load system 20, a parallel circuit of a capacitor 40 and reactor 41 is provided in series with the transmission line 30 and the equivalent capacity of the parallel circuit is changed by controlling the phase of the electric current flowing to the reactor 41 by means of thyristors 42 and 43. The thyristors 42 and 43 are controlled in accordance with operation command values Zp given to a pulse phase controller 401 from the outside, commands from a control output device 400 based on a COM, a judging circuit 402 which judges whether the impedance of the capacitor 40 is capacitive or inductive, and a voltage detector 44 which detects the voltage of the capacitor 40. Therefore, the reactance compensation of the transmission line 30 can be controlled to be stable at a high speed. |
