| 摘要 |
PURPOSE:To perform the opening of a short-circuit switch on the primary side of an AC excitation type synchronous machine in a short time in the case of its pumping operation, by so controlling the voltage component generated on the secondary side of the synchronous machine as to be made zero in the case of the opening of its primary side. CONSTITUTION:From the secondary side of an AC excitation type synchronous machine 1, a variable-frequency power supply voltage is applied to it by a power converter 3, and the rotational speed of the AC excitation type synchronous machine 1 is increased to its specified rotational speed. In this time, on the primary side of the synchronous machine 1, a current having the low frequency which is the difference frequency between the frequency of the variable-frequency power supply applied to the synchronous machine 1 from its secondary side and the rotational frequency of the synchronous machine 1 is induced. After speed-up, in order that a variable-speed pumping operation is performed through the opening of the short-circuit switch 2, the voltage component generated on the secondary side of the synchronous machine 1 is made zero through the control of the power converter 3 by a controlling circuit 3a. Thereby, the low-frequency current is made zero, and the opening of the short- circuit switch 2 in the case of the pumping operation can be performed in a short time. |
