Torsional fatigue of turbine-generator shafts owing to network faults

Chyn, C.; Wu, Ray; Tsao, Ta‐Peng

doi:10.1049/ip-gtd:19960598

Cited by 43 publications

(16 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, large conventional generators are susceptible to resonance of torsional oscillations, because of long shaft lengths and several rotating inertias, greatly increasing the torsional stress at certain points on the shaft [4 -7]. This can lead to shaft fatigue life expenditure and failure [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Effect of loading, voltage difference and phase angle on the synchronisation of a small alternator

Best

Morrow

Crossley

2009

IET Electr. Power Appl.

View full text Add to dashboard Cite

Synchronisation of small distributed generation, 30 kVA -2 MVA, employing salient-pole synchronous machines is normally performed within a narrow range of tolerances for voltage, frequency and phase angle. However, there are situations when the ability to synchronise with non-ideal conditions would be beneficial. Such applications include power system islanding and rapid generator start-up. The physical process and effect of out-of-phase synchronisation is investigated both through simulation and experimental tests on a salientpole alternator. There are many factors that affect synchronisation, but particular attention is given to synchronisation angle, voltage difference and, as generators will be loaded during islanding, the load angle. The results suggest that it would be acceptable for the maximum synchronisation angle of distributed generation to exceed that of current practice. Interesting observations on the nature of out-of-phase synchronisation are made, including some specific to small salient-pole synchronous machines. Furthermore, recommendations are made for synchronisation under different system conditions.reactance a angular acceleration u sync synchronisation angle d load angle t time constant F magnetic flux C flux linkage v angular speed Subscripts and superscripts a armature bus power system bus d direct axis (armature) e electrical f field k d direct-axis damper k q quadrature axis damper m mechanical m d direct-axis mutual m q quadrature-axis mutual

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of loading, voltage difference and phase angle on the synchronisation of a small alternator

Best

Morrow

Crossley

2009

IET Electr. Power Appl.

View full text Add to dashboard Cite

show abstract

“…To prevent the bearing stress from exceeding the material yielding point following a three-phase fault at the power plant terminal, the lowest SFs for different blades are evaluated in Table V [2]. The corresponding critical E/M disturbing torques which damage the Table V.…”

Section: Effect Of the E/m Disturbing Torquementioning

confidence: 99%

“…Earlier, a research series focused on the unstable subsynchronous resonance (SSR) issue due to series compensation Scheme [1]. Subsequently several publications investigated the overstress problem on turbine mechanism subjected to large-signal disturbances, such as network faults, even without series compensation [2]. Therefore, numerous countermeasures have been proposed to deal with these troublesome problems [3].…”

Section: Introductionmentioning

confidence: 99%

Fatigue life expenditure assessment and countermeasure for turbine blades due to harmonic excitations of slip energy recovery drives

Tsai

2008

Int Trans Elec Energy Syst

View full text Add to dashboard Cite

SUMMARYThe long-term effect of noncharacteristic harmonic currents arising from a slip energy recovery drive (SERD) on the fatigue life expenditure in turbine-generator blades is presented in this paper. Since the SERD converter can be rated at a fraction of a motor due to its static converter cascade with the wound-rotor and with high efficiency characteristics, still the feedwater pumps (FPs) in a few power plants are driven by such an induction motor (IM) drive. However, because the frequencies of the three main harmonic terms of the recovery currents are subsynchronous and offer a probability distribution due to the adjustable speed operation, a systematic fatigue estimation approach was devised by the author to investigate the long-term impact for the low-pressure (LP) turbine blades. From the simulation results, it was found that such a long-term harmonic excitation becomes a cause of turbine blade failure for single generator connected to the SERD system, even though the amplitude of these harmonic currents is normal. By the effect analysis of uncertainty, the countermeasure for the turbine integrity was then found.

show abstract

“…Since the bending torque of the last stage blade on each low-pressure steam turbine is 0.0238 pu and the value of blade centrifugal stress is 0.0344 pu, the working stress of the blade is 0.0418 times of the machine base. The stress corresponding to 10 5 cycles-tofailure in S-N curve is used as the base of the shaft working stress with the safety factor (SF) at 1 [13,14]. When the designed SF is more than one, the equivalent working stress must decrease by 1/SF degrees.…”

Section: Long-term Fatigue Life Estimationmentioning

confidence: 99%

Application of the optimal damper on damping turbine-generator torque vibrations in a HVDC link

Tsai

2006

2006 IEEE Power Engineering Society General Meeting

View full text Add to dashboard Cite

Due to more various power disturbances occurring in a power system involving a HVDC link, the turbine generator shafts and/or blades are more prone to damage than in general HVAC systems. In this paper, a new mechanical damper scheme based on participation factor approach is proposed to damp torsional torque and prolong the life of turbine mechanism. Two types of torsional damping couplings, inertia damping coupling and elastic damping coupling, are adopted and examined. The optimal type and the optimal location of the damping coupling will be identified and installed to the turbine generator shaft section. The simulation results demonstrate that the best damper may not be installed at the location with the most onerous vibrations but provides satisfactory damping performance on shafts and blades following severe power disturbances in a HVDC link.

show abstract

Torsional fatigue of turbine-generator shafts owing to network faults

Cited by 43 publications

References 1 publication

Effect of loading, voltage difference and phase angle on the synchronisation of a small alternator

Effect of loading, voltage difference and phase angle on the synchronisation of a small alternator

Fatigue life expenditure assessment and countermeasure for turbine blades due to harmonic excitations of slip energy recovery drives

Application of the optimal damper on damping turbine-generator torque vibrations in a HVDC link

Contact Info

Product

Resources

About