Apparatus for stabilizing turbine-generator shaft torsional oscillations

Abstract

An apparatus for stabilizing turbine generator shaft torsional oscillations including: a current detector for detecting ac current of a turbine generator used in combination with a dc power-transmission system, a filter to which an output of said current detector is delivered, the filter comprising a first bandpass filter for detecting a sub synchronous component (f.sub.l -f.sub.m) and a second bandpass filter for detecting a super synchronous component (f.sub.l +f.sub.m) where a fundamental freuency of the generator is represented by f.sub.l and a natural frequency of the mechanical shaft system of the generator is represented by f.sub.m, a calculation circuit for applying conversion of at least one of d and q axis to respective outputs from the first and second bandpass filters using a generator phase .theta..sub.G to take out at least one of .DELTA.i.sub.d and .DELTA.i.sub.q of the sub and super synchronous components, a third bandpass filter to which an output from the calculation circuit is fed, the third bandpass filter for taking out a stabilization signal therefrom, and a circuit for controlling a converter for delivering an output of the generator to the dc power-transmission system on the basis of the stabilization signal.

Dependencies are inferred from the claim text.