摘要 |
PROBLEM TO BE SOLVED: To detect a frequency other than a shaft torsional vibration frequency region according to the bus voltage of a DC conversion station, and to efficiently suppress and control shaft torsion. SOLUTION: A device is equipped with frequency detectors 142a-142c that detect frequencies fa, fb, and fx of each phase according to phase voltages Va, Vd, and Vc of an AC bus 5 of a DC conversion station being connected to a generator 2, an averaging circuit 143 that obtains the average value of the frequencies fa, fb, and fc for detecting the frequency of the bus 5, a filter 144 and a judgment circuit 145 that detect shaft torsional vibration according fluctuation in the frequency of the bus 5, a filter 147 that detects a control signal for suppressing the detected shaft torsional vibration, and an adder 150 that adds the control signal to the output of a constant current-controlling device 149. By the output of the adder 150, the control angle of the DC conversion station is adjusted for suppressing the shaft torsional vibration. |