Observer-Based Active Control of Torsional Vibration for Large Turbine-Generator Shaft System

2010 ◽  
Author(s):  
Liming Feng ◽  
Wenzhi Gao ◽  
Congmin Tan ◽  
Hao Qin ◽  
Bixian Xie ◽  
...  
Keyword(s):  
Active Control ◽  
Torsional Vibration ◽  
Turbine Generator ◽  
Shaft System

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.

An Investigation of Torsional Wave Control in a Multiple Stepped Turbogenerator Shaft System

2001 ◽  
Author(s):  
Zhiyong Hao ◽  
Min Ye ◽  
Luhua Fu
Keyword(s):  
Active Control ◽  
Torsional Vibration ◽  
Control Process ◽  
Wave Theory ◽  
Fast Response ◽  
Torsional Wave ◽  
Mass Model ◽  
Shaft System ◽  
Turbo Generator ◽  
Continuous Mass

Abstract In the paper, a new analysis method is presented for calculating the torsional wave in a multi-stepped shaft system according to the elastic wave theory, and it is used to simulate the torsional vibration of a turbo-generator shaft system (TSS). Based on the continuous mass model, an active control strategy for minimizing the total energy of torsional vibration in a TSS is deduced against the excitation due to short circuits in the generator or ground faults in the electric network. The responses of torsional vibration and their control process are simulated under the different operate condition. It is shown that active control can not only achieve good vibration attenuation and a fast response to the faults, but also adapt the change of exciting load and work effectively in all of the operating range of the machine.

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.

Analysis and enhancement of torsional vibration stopbands in a periodic shaft system

2013 ◽  
Vol 46 (14) ◽  
pp. 145306 ◽  
Author(s):  
Yubao Song ◽  
Jihong Wen ◽  
Dianlong Yu ◽  
Xisen Wen
Keyword(s):  
Torsional Vibration ◽  
Shaft System

Analysis of Models for Torsional Vibration of Shaft System With Planetary Gearing

1997 ◽  
Author(s):  
Jinghui Sun ◽  
Lee Liu ◽  
William N. Patten
Keyword(s):  
Torsional Vibration ◽  
Planetary Gear ◽  
Gear Train ◽  
Mathematical Treatment ◽  
Dynamic Parameters ◽  
Mass Model ◽  
Planar Model ◽  
Shaft System ◽  
Effective Dynamic ◽  
Single Mass

Abstract The kinematics of planetary gearing are complex; thus, making it difficult to build an effective dynamic model. In this paper, a single-mass model of a planetary gear and shaft system is developed to study the torsional vibration of the mechanism. Two new models of the system are proposed: (a) a fictitious co-planar model and (b) an equivalent shaft model. The results from the calculations and analyses using these models indicate that: 1) the single-mass model and the general rotary model are both limited, either mathematically or geometrically; 2) the fictitious co-planar model includes all of the geometric and dynamic parameters of the general rotary model, and it can be connected with the shaft system easily; and 3) using a mathematical treatment, the equivalent shaft model is demonstrated to be the most useful and most effective model for the calculation of torsional vibration of a shaft and planetary gear train.

Coupled Torsional Vibration and Fatigue Damage of Turbine Generator Due to Grid Disturbance

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Chao Liu ◽  
Dongxiang Jiang ◽  
Jingming Chen
Keyword(s):  
Fatigue Damage ◽  
Torsional Vibration ◽  
Coupled System ◽  
Lumped Mass ◽  
Mass Model ◽  
Turbine Generator ◽  
Failure Prevention ◽  
Lumped Mass Model ◽  
Continuous Mass ◽  
Fatigue Evaluation

Crack failures continually occur in shafts of turbine generator, where grid disturbance is an important cause. To estimate influences of grid disturbance, coupled torsional vibration and fatigue damage of turbine generator shafts are analyzed in this work, with a case study in a 600MW steam unit in China. The analysis is the following: (i) coupled system is established with generator model and finite element method (FEM)-based shafts model, where the grid disturbance is signified by fluctuation of generator outputs and the shafts model is formed with lumped mass model (LMM) and continuous mass model (CMM), respectively; (ii) fatigue damage is evaluated in the weak location of the shafts through local torque response computation, stress calculation, and fatigue accumulation; and (iii) failure-prevention approach is formed by solving the inverse problem in fatigue evaluation. The results indicate that the proposed scheme with continuous mass model can acquire more detailed and accurate local responses throughout the shafts compared with the scheme without coupled effects or the scheme using lumped mass model. Using the coupled torsional vibration scheme, fatigue damage caused by grid disturbance is evaluated and failure prevention rule is formed.

Error Considerations for Turbine-Generator Torsional Vibration Monitoring

2020 ◽  
Author(s):  
Jindrich Liska ◽  
Jan Jakl ◽  
Sven Kunkel
Keyword(s):  
Power Systems ◽  
Torsional Vibration ◽  
Gas Turbines ◽  
Measurement Errors ◽  
Power Plants ◽  
Signal To Noise Ratio ◽  
Vibration Monitoring ◽  
Turbine Generator ◽  
Turbine Generators ◽  
Incremental Encoder

Abstract Turbine-generator torsional vibration is linked to electrical events in the power grid by the generator air-gap torque. Modern power systems are subject to gradual transformation by increasing flexibility demands and incorporation of renewable resources. As a result, electrical transient events are getting more frequent and thus torsional vibration is getting more and more attention. Especially in the case of large steam and gas turbines torsional vibration can cause material fatigue and present a hazard for safe machine operation. This paper freely builds on previous work, where a method for torsional vibration evaluation using an incremental encoder measurement was presented, in that it supplements error considerations to this methodology. Measurement errors such as precision of the rotor encoder manufacturing, choice of the proper sensor, its signal to noise ratio and the error of instantaneous velocity computation algorithm are analyzed. The knowledge of these errors is essential for torsional vibration as there is an indirect and relatively complicated path from the measurement to the final torsional vibration results compared to other kinds of vibration. The characteristics of particular errors of the processing chain are validated both on experimental data from a test rig as well as field data measured on turbine-generators in power plants.

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