| 摘要 |
PURPOSE:To perform operation continuously within the limiting value of a secondary exciting voltage by resetting a speed command value, when a fault occurrence preview signal in a power transmission area is issued. CONSTITUTION:The secondary side of a variable speed induction machine 1 is directly coupled to a reversible pumpturbine 2, the primary side thereof is connected with an electric power system, and a secondary exciter 3 composed of a frequency converter is connected with the secondary side to supply a secondary winding with power. A rotational speed detected by a speed detector 5 is compared with that of a speed command generator 7, and the deviation thereof is given to a secondary current command setting circuit 14 via a speed control function generator 9 and controlled so that the speed becomes a command value. Similarly, and output voltage is detected by a voltage sensor 10 and the deviation from the output of a voltage command generator 11 is given to the secondary current command setting circuit 14 via a voltage-controlled generator 13. When a preview signal is inputted from a lightning preview information receiver 20, the speed command value is changed by a resetting device 21 and an apparatus can continue operation within the limited range of a secondary exciting voltage even if an abnormality occurs. |
