Comparison of turbine-generator shaft torsional response predicted by frequency domain and time domain methods following worst-case supply system events

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · IEEE Transactions on Energy Conversion (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/60.257074· OSTI ID:5528903

Hammons, T J; McGill, J F ^[1]

---

1. Glasgow Univ., Scotland (United Kingdom)

The paper examines precision of predicting time response for torque in turbine-generator-exciter shafts by frequency-domain analysis following incidence and clearance of short-circuits, etc. on the electrical supply system. The analysis is based on Fourier analysis of generator air gap torque following incidence and clearance of a supply network disturbance or following worst-case mal-synchronization to obtain torque excitation which acts on the generator rotor corresponding to each modal vibration. Amplitude and phase of each vibration is thereby determined. Using appropriate damping, time responses for shaft torque at each shaft cell is constructed by summing components which correspond to each frequency of modal vibration of the shaft. These time responses are compared with those obtained by solution of more than 50 differential equations which simulate the shaft train, turbine, generator, exciter, electrical supply system, the fault clearing process, the turbine governor, and the generator excitation system. It is shown that time responses for transient turbine-generator-excitor shaft torques can be predicted faithfully by frequency domain analysis taking due account of magnitude and phase of each modal vibration, and damping, following (1) worst-case Line-Line-Line, Line-Line, and Line-Ground disturbances from full-load to no-load, with clearance, and (2) mal-synchronization. Rotor swing has a significant influence on transient turbine shaft torque at shaft locations in proximity to the generator, but the effect decreases almost in direct proportion to turbine inertia which is accelerated by rotor swing. Simulation of damping of rotor swing is important in making precise assessments of transient turbine shaft torque at shaft locations which are close to the generator. Predominance of a particular modal vibration at different shaft locations is dependent on the fault clearing time, and varies cyclically as the fault clearing time is raised.

• OSTI ID: 5528903
• Journal Information: IEEE Transactions on Energy Conversion (Institute of Electrical and Electronics Engineers); (United States), Vol. 8:3; ISSN 0885-8969
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
MECHANICAL SHAFTS
TORSION
POWER SYSTEMS
ELECTRICAL TRANSIENTS
TURBOGENERATORS
FREQUENCY DEPENDENCE
MATHEMATICAL MODELS
OSCILLATION MODES
ELECTRIC GENERATORS
ENERGY SYSTEMS
EQUIPMENT
MACHINE PARTS
MACHINERY
SHAFTS
TRANSIENTS
TURBOMACHINERY
VOLTAGE DROP
240100* - Power Systems- (1990-)