Characteristic Study of Torsional Vibration on a Full Size Turbine-Generator Unit

1991 ◽  
Author(s):  
Huang Xiuzhu ◽  
Zhang Xueyan ◽  
Sun Daixia ◽  
Gong Qing
Keyword(s):  
Torsional Vibration ◽  
Vibration Characteristics ◽  
Turbine Generator ◽  
Full Size ◽  
Torsional Response ◽  
Shaft System ◽  
Switch Operation ◽  
Shaft Torque ◽  
Generator Unit

Abstract Taking a 200MW turbine-generator unit and its connected transsmision network as a study object, torsional vibration characteristics of the shaft system caused by faulty synchronization, different disturbances in the network and switch operation were analysed and calculated. The effect of intensive excitation and “fast valve closing” on the torsional response is also discussed. It is concluded that large mechanical torque of shaft system would be encountered if there is a 3-phase fault in the network, and the shaft torque would be reduced to a certain extent by giving the “fast valve closing” if the network experience a fault.

Torsional Vibration Analysis and Stress Calculation for the Fault 600MW Steam Turbine Generator Shaft System

2009 ◽  
Author(s):  
Dongxiang Jiang ◽  
Liangyou Hong ◽  
Zheng Wang ◽  
Xiaorong Xie
Keyword(s):  
Steam Turbine ◽  
Torsional Vibration ◽  
Operation Condition ◽  
Turbine Generator ◽  
Modal Shape ◽  
Subsynchronous Oscillation ◽  
Root Cause ◽  
Shaft System ◽  
Mass Element ◽  
Rotor Dynamic

Subsynchronous oscillation (SSO) or torsional vibration may cause shaft of steam turbine generator hurt heavily. This phenomenon has destroyed two generator shafts in one of China’s power plant in 2008. Detailed analysis and several measurements have been taken to identify the reason of the accident. First, the operational data is analyzed, including field torsional vibration dada. Then, the modal of the shaft system is calculated. Each torsional vibration frequency is gotten with corresponding modal shape. Dangerous location of the shaft system is obtained. Third, torque value of different operation condition is calculated based on two different models: one is traditional multiple mass element rotor dynamic model and the other is an four mass element electromechanical model of rotor oscillation. Following, the maximum stress on the dangerous location is calculated using finite element method. Finally, the root cause of shaft destruction is analyzed and identified.

Vibration Characteristics and Damage of Turbine Generator Shaft Rubbing

2014 ◽  
Vol 697 ◽  
pp. 210-213 ◽  
Author(s):  
Rong Pei Zhang
Keyword(s):  
Temperature Change ◽  
Vibration Characteristics ◽  
Lubricating Oil ◽  
Turbine Generator ◽  
Rotor Shaft ◽  
Turbo Generator ◽  
Deep Groove ◽  
No Elimination ◽  
Generator Unit

An abnormal journal vibration occurred when a 660MW turbo generator unit was in daily operation. It was identified that rubbing vibration had taken place based on the behavior of the journal vibration and the temperature change of lubricating oil. The rubbing was located inside the bearing box between the HIP rotor and the LP rotor. However, no elimination measures had been taken in time because the damage caused by rubbing was underestimated. Few months later a full inspection revealed that the LP rotor shaft had been worn out with a 70mm wide and 28mm deep groove, which greatly weakened the strength of the LP rotor. The analysis presented here may help in diagnosing and understanding rubbing-vibration-related problems in similar situations.

An Increment Transfer Matrix Method for the Torsional Vibration Response of Steam Turbo-Generator Shaft System

2010 ◽  
Vol 34-35 ◽  
pp. 1082-1087 ◽  
Author(s):  
Cheng Bing He ◽  
Cheng Xing ◽  
Jian Shen
Keyword(s):  
Transfer Matrix ◽  
Torsional Vibration ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Short Circuit ◽  
Nonlinear Differential Equations ◽  
Mass Model ◽  
Shaft System ◽  
Turbo Generator ◽  
Generator Unit

In order to solve nonlinear system torsion response of turbo-generator unit, an increment transfer matrix method based on step-by-step integration method and traditional transfer matrix method was put forward. The method can be directly used to analyze nonlinear differential equations. Combined with Riccati method, the increment transfer matrix method was used in a multi-mass model. And matrix equations calculating the responses of torsional vibrations were deduced. Torsional vibration resulted from the faults of short circuit and asynchronous synchronization of 600MW steam turbo-generator unit were discussed in this work by using the increment transfer matrix method which can also extend the application of transfer matrix method in nonlinear field.

Analysis of Flexural and Torsional Vibration for Turbogenerator Shafts on Power Impact

2010 ◽  
Vol 139-141 ◽  
pp. 2498-2501
Author(s):  
Ling Xiang ◽  
Shi Xi Yang
Keyword(s):  
Torsional Vibration ◽  
Simulation Experiment ◽  
Flexural Vibration ◽  
Vibration Characteristics ◽  
Rotor System ◽  
Rigid Support ◽  
Turbine Generator ◽  
Torsion Vibration ◽  
Jeffcott Rotor ◽  
Faults Diagnosis

Based on a Jeffcott rotor system with rigid support, the math models of flexural and torsional vibration were built, and their vibration characteristics were concluded. A simulation experiment in this paper was designed about the flexural and torsional vibration of shafts on a simulated turbine generator during network impacts. By analysis, flexural and torsional vibration characteristics were obtained, and the results showed the shafts flexural vibration and torsional vibration were interacted with each other. It was provided that torsional vibration could inhibit the complex shafts exercise. A new idea was suggested that the characteristics of torsion vibration should be considered as the symptom of faults diagnosis

Hybrid reliability model of hydraulic turbine-generator unit based on nonlinear vibration

2013 ◽  
Vol 228 (11) ◽  
pp. 1880-1887 ◽  
Author(s):  
Zhaojun Li ◽  
Yang Liu ◽  
Fuxiu Liu ◽  
Xujuan Yang
Keyword(s):  
Nonlinear Vibration ◽  
Multiple Scales ◽  
Hydraulic Turbine ◽  
Reliability Model ◽  
Turbine Generator ◽  
Nonlinear Dynamic Equation ◽  
Shaft System ◽  
Hybrid Reliability ◽  
Generator Unit ◽  
Excitation Frequencies

In order to study the vibration reliability of hydraulic turbine-generator unit, the nonlinear dynamic equation of the main shaft system of hydraulic turbine-generator unit is established by the finite element method. Then the nonlinear vibration characteristics of the system are analyzed and the excitation frequencies of the system are obtained by the method of multiple scales. Based on the criterion that the absolute values of difference between the natural frequencies and excitation frequencies of the system should be less than specific values, the hybrid probabilistic, nonprobabilistic, and fuzzy reliability model of the system based on nonlinear vibration is constructed. By the hybrid reliability model, the reliability of system can be calculated. Finally, an example is presented.

scholarly journals The Transient Torsional Vibration Behaviour of a Turbine-Generator System Under Short Circuit Excitation

1996 ◽  
Author(s):  
Dennis S. H. Chan
Keyword(s):  
Torsional Vibration ◽  
Power Plants ◽  
Short Circuit ◽  
Sudden Change ◽  
Combined Cycle ◽  
Turbine Generator ◽  
Generator System ◽  
Torsional Response ◽  
System Vibration ◽  
Short Circuits

Turbine-generator systems are subjected to sudden short circuits. The sudden change of electrical characteristics in these systems can incur very high excitation torques on the components. The excitation depends on the types of short circuits and the electrical properties of the generator, etc. Transient torsional vibration due to generator short circuit is investigated in this paper. Typical short circuit excitation functions are discussed. A modern gas turbine / generator / steam turbine system is used to illustrate the effects of modelling inaccuracies and parameter variations. The acceptance standards for such transient short circuit conditions are generally based on maximum torque transmitted or some kind of allowable shear stress. They cannot be accurately predicted by models which use 1–2 disks (stations) to represent a major machine in a train. Either a more refined model or a better reduction method is needed. Flexible couplings affect the transient torsional response and they must be included in the system vibration analysis. Their influence on the peak transmitted torque has been examined. The selection of couplings for turbine-generator systems in modern combined cycle power plants should be emphasized.

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