| 摘要 |
PROBLEM TO BE SOLVED: To shorten the time needed until adaptable electric power reaches a steady state at the time of the starting of a DC power transmission system or at the time of recovery from an accident. SOLUTION: Usually, a DC voltage control circuit 10 outputs a firing angle αAVR on the basis of the input of a DC voltage set value Edp 9, and a DC current control circuit 13 outputs a firing angle αACR on the basis of the input of a deviation between a DC current detection value Id and a DC current set value Idp. A maximum value selecting circuit 14 selects larger one of those firing angles to output it as a control signal for its own power converter. At the time of the starting, the firing angle αACR of the DC voltage control circuit 10 of which the operation speed is slow is selected. On a reverse converter side, since the AND conditions of an AND circuit 17 come into existence, a switch circuit 18 is turned on, and the change part ΔE of the DC voltage set value is subtracted from the DC voltage set value Edp. Therefore, a voltage difference between a forward converter and a reverse converter becomes large, so that adaptable electric power may be increased at high speed. |
