الفهرس 
Nature of SSO
Turbo-Generator Models For SSO A.nalysisOnly 14 pages are availabe for public view
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Abstract
This research presents a method for suppressing torsional oscillations
phenomenon in large turbo-generators as a result of series compensation
in power systems. The subsynchronous frequency oscillations (SSO) which
are discussed in this work are in the frequency range 5-45 Hz. The
subsynchronous frequency oscilJations are associated with stimulation of
turbine-generator natural torsional modes and are initiated by an electrical
disturbance. Alternatively, these oscillations may arise from a near
resonant interaction between a turbine-generator rotor and either a
series capacitor compensated transmission line or an HYDe. control system.
The concern with the shaft oscillations of a turbine-generator is that the
repeated stimulation can lead to the loss of life of the shaft egments as a
result of fatigue phenomenon.
The proposed method utilizes a thyristor controlled static phase-shifter with
a newly designed control system to modulate the generator active power. The
control system is based on modal speed deviations as a feed back control
signals. The study is performed on a single machine connected to a large
network via a series compensated transmission line. The eigenvalue analysis
method is used to adjust the constants of the phase-shifter control system and
to verify the effect on the stability of the torsional and the low frequency
electro-mechanical modes.
The results indicate that, the static phase-shifter with its control system is
capable of providing positive damping to the electro-mechanical mode and
the unstable torsional modes in a wide range of series compensation. To
verify the eigenvalue analysis results, detailed digital computer simulation
studies are conducted using the time domain analysis and the results are
compared with those obtained from the eigenvalue method.