Analysis of variable-frequency currents superimposed on DC currents in asynchronous HVDC links in stressing turbine-generator-exciter shafts

Author

Hammons, T.J. ; Bremner, J.J.

Author_Institution

Glasgow Univ., UK

Volume

10

Issue

1

fYear

1995

fDate

3/1/1995 12:00:00 AM

Firstpage

95

Lastpage

104

Abstract

The paper makes an indepth analysis of the excitation of shaft torsional vibrations in steam turbine-generator-exciter shafts by variable-frequency ripple currents superimposed on DC currents in asynchronous links using the finite element and reduced models of the machine shafts. Frequencies at which sympathetic shaft torsional vibrations would be excited by modulation product harmonics in 50 Hz/50 Hz and 50 Hz/60 Hz asynchronous links as a function of deviation in system frequency are illustrated. It is shown that amplitude of shaft torque due to steady resonant torque excitation is a function of initial rate of increase of vibrations at adjacent cells, the time constant for decay of the vibration, and stiffness between adjacent shaft cells

Keywords

HVDC power convertors; HVDC power transmission; finite element analysis; machine theory; power system harmonics; steam turbines; torque; torsion; turbogenerators; vibrations; 50 Hz; 60 Hz; DC current superimposition; HVDC; asynchronous links; finite element model; machine shafts; modulation product harmonics; reduced model; resonant torque excitation; shaft torque amplitude; steam turbine-generator exciter shafts; stiffness; time constant; torsional vibrations; variable-frequency ripple currents; vibration decay; DC generators; Damping; Finite element methods; HVDC transmission; Power generation; Resonance; Resonant frequency; Shafts; Synchronous generators; Torque;

fLanguage

English

Journal_Title

Energy Conversion, IEEE Transactions on

Publisher

ieee

ISSN

0885-8969

Type

jour

DOI

10.1109/60.372573

Filename

372573