The effect of the rotor adjustment on the vibration behaviour of the drive-train system for a 5 MW direct-drive wind turbine

Author(s):  
Kan Ye ◽  
Jinchen Ji

Direct-drive wind turbines, different from the standard geared wind turbines, widely use a direct-drive permanent-magnet generator to avoid the gearbox failures. In the absence of a gearbox in the drive-train system, the direct-drive generator operates at low rotating speeds. Thus direct-drive wind turbines require a larger sized generator (higher weight) to transfer the kinetic energy into electrical energy. The inherent unbalanced magnetic pull force of the generator can have impact on the vibration behaviour of the drive-train system. This paper studies the effect of rotor position and weight adjustment on the vibration behaviour of the drive-train system within a 5 MW direct-drive wind turbine by considering the unbalanced magnetic pull force. The adjustment of rotor position and weight changes the location of the centre of gravity of the drive-train system. The drive-train system which consists of the main shaft, rotor, hub and blades is modelled as a four degree-of-freedom nonlinear system. Both rotor displacement and bearing forces are obtained for a wide range of rotor position and weight under different rotating speeds. The obtained results would provide useful information on the optimized rotor position and mass ratio to improve the performance of the drive-train system.

2013 ◽  
Vol 347-350 ◽  
pp. 1953-1956
Author(s):  
Zhen Xie ◽  
Gao Fei Lv ◽  
Fei Teng

In this paper, we focus on modeling, oscillatory stability analysis of the drive train system and the transient performances of wind turbine with doubly fed induction generator (DFIG) wind turbines, which are evaluated under sub-synchronous operation during the grid voltage fault. Results have shown that the oscillatory stability and shafting parameters have a close relationship, it is necessary to consider the drive train system while the transient performances of DFIG wind turbines are analyzed.


2019 ◽  
Vol 44 (5) ◽  
pp. 519-547
Author(s):  
Saeed Asadi ◽  
Håkan Johansson

Wind turbines normally have a long operational lifetime and experience a wide range of operating conditions. A representative set of these conditions is considered as part of a design process, as codified in standards. However, operational experience shows that failures occur more frequently than expected, the costlier of these including failures in the main bearings and gearbox. As modern turbines are equipped with sophisticated online systems, an important task is to evaluate the drive train dynamics from online measurement data. In particular, internal forces leading to fatigue can only be determined indirectly from other locations’ sensors. In this contribution, a direct wind turbine drive train is modelled using the floating frame of reference formulation for a flexible multibody dynamics system. The purpose is to evaluate drive train response based on blade root forces and bedplate motions. The dynamic response is evaluated in terms of main shaft deformation and main bearing forces under different wind conditions. The model was found to correspond well to a commercial wind turbine system simulation software (ViDyn).


Author(s):  
Hideyuki Suzuki ◽  
Yu Kitahara ◽  
Yukinari Fukumoto

A wide range of platform concepts have been investigated for a floating wind turbine. So far analysis and design of motion characteristics of the platform is main research concern. One key research area less focused is floating platform related risk. If the wind energy would be one of the major sources of electric power supply, wind farms which are comprised of large number of floating wind turbines must be deployed in the ocean. Wind turbines are relatively closely arranged in a wind farm. In such an arrangement, a wind turbine accidentally started drifting will have some possibility to collide with floater and moorings of neighboring moored floating wind turbines, and might initiate another drift which might cause progressive drifting of wind turbines. In the previous report, a scenario of progressive drifting of wind turbines was investigated and associated risk was formulated. Quantitative risk of several arrangements of wind farm was estimated. Effects of arrangement of wind turbines in a wind farm and safety factor used in the design of moorings is discussed. Probability of initial drift was evaluated analyzing past records of accidents and design of mooring. In this research, strength of mooring system was modeled more precisely and probabilistic model was developed considering aged deterioration. Risk of progressive drifting was evaluated and safety factor required to realize a acceptable risk of a wind farm was discussed.


Author(s):  
K. Vafiadis ◽  
H. Fintikakis ◽  
I. Zaproudis ◽  
A. Tourlidakis

In urban areas, it is preferable to use small wind turbines which may be integrated to a building in order to supply the local grid with green energy. The main drawback of using wind turbines in urban areas is that the air flow is affected by the existence of nearby buildings, which in conjunction with the variation of wind speed, wind direction and turbulence may adversely affect wind energy extraction. Moreover, the efficiency of a wind turbine is limited by the Betz limit. One of the methods developed to increase the efficiency of small wind turbines and to overcome the Betz limit is the introduction of a converging – diverging shroud around the turbine. Several researchers have studied the effect of shrouds on Horizontal Axis Wind Turbines, but relatively little research has been carried out on shroud augmented Vertical Axis Wind Turbines. This paper presents the numerical study of a shrouded Vertical Axis Wind Turbine. A wide range of test cases, were examined in order to predict the flow characteristics around the rotor, through the shroud and through the rotor – shroud arrangement using 3D Computational Fluid Dynamics simulations. The power output of the shrouded rotor has been improved by a factor greater than 2.0. The detailed flow analysis results showed that there is a significant improvement in the performance of the wind turbine.


Author(s):  
Hideyuki Suzuki ◽  
Masaru Kurimoto ◽  
Yu Kitahara ◽  
Yukinari Fukumoto

A wide range of platform types have been investigated for a floating wind turbine. Most of the research projects on a floating wind turbine assume that a land based wind turbine is to be installed on a platform with minimum modification to reduce the overall cost. For this reason, allowable limit of a motion of wind turbine is limited to lower value, for example, five degrees for static inclination and one to two degrees for pitching motion. So far analysis and design of motion characteristics of the platform have been main research concern. One key research area less focused is floating platform related risk. If the wind energy would be one of the major sources of power supply, wind farms which are comprised of large number of floating wind turbines must be deployed in the ocean. Wind turbines will be closely spaced in a wind farm so that installation cost should be minimized. In such an arrangement, a wind turbine accidentally started drifting has some possibility to collide or contact with the moorings of neighboring wind turbines and might cause progressive drifting of wind turbines. This paper present investigation of scenario of progressive drifting of floating wind turbines and evaluate risk of the scenario. Quantitative risk of several arrangements of wind farms is estimated. Effect of arrangement of wind turbines in a wind farm and safety factor used in design moorings is discussed.


2019 ◽  
Vol 23 (2) ◽  
pp. 174-203
Author(s):  
Gonzalo Abad ◽  
Aritz Milikua ◽  
Igor Baraia-Etxaburu ◽  

Wind turbines have been used by many groups of humans for many centuries. Wind turbines have allowed groups of humans to perform many different tasks in the past (grinding grain, pumping water, etc.). However, only a century and a half ago, they began to be used to convert the energy captured from wind into electric energy. Moreover, only approximately twenty-five years ago, we started to introduce on a massive scale the energy generated from wind turbines into the electric networks of most developed countries in the world for regular consumption. According to 2017 statistics, approximately 12 percent of the electric energy consumed in the EU is produced by wind turbines. Despite the fact that wind turbines generally appear quite similar externally—i.e., a three-blade structure, a nacelle, a tower, etc.—if we carefully examine the electric technology used within them, we find quite a wide range of technologies for energy conversion, which is a key issue in wind turbine technology. Hence, this paper adopts a dialectic perspective towards analyzing and understanding why several electric technologies coexist in wind turbine technology. We explain the specific factors that have influenced different wind turbine manufacturers to adopt different electric technologies across the last twenty-five years. We show how their actions and the technological directions that have followed have been mutually codetermined, resulting in a technological evolution that has produced today’s wind turbine variety.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3034 ◽  
Author(s):  
Samet Ozturk ◽  
Vasilis Fthenakis ◽  
Stefan Faulstich

The failure of wind turbines is a multi-faceted problem and its monetary impact is often unpredictable. In this study, we present a novel application of survival analysis on wind turbine reliability, including accounting for previous failures and the history of scheduled maintenance. We investigated the operational, climatic and geographical factors that affect wind turbine failure and modeled the risk rate of wind turbine failure based on data from 109 turbines in Germany operating for a period of 19 years. Our analysis showed that adequately scheduled maintenance can increase the survival of wind turbine systems and electric subsystems up to 2.8 and 3.8 times, respectively, compared to the systems without scheduled maintenance. Geared-drive wind turbines and their electrical systems were observed to have 1.2- and 1.4- times higher survival, respectively, compared to direct-drive turbines and their electrical systems. It was also found that the survival of frequently-failing wind turbine components, such as switches, was worse in geared-drive than in direct-drive wind turbines. We show that survival analysis is a useful tool to guide the reduction of the operating and maintenance costs of wind turbines.


2015 ◽  
Vol 789-790 ◽  
pp. 311-315 ◽  
Author(s):  
Yan Li Cheng ◽  
Zheng Ming Xiao ◽  
Li Rong Huan ◽  
Fu Chen

The speed increasing gearbox is the key part of the wind turbine and its role is to transmit power which is generated by wind turbines to the generator through the gear system. The single-stage planetary gears train system is commonly used in the semi-direct drive wind turbines. In this paper Pro/E is used to establish the three-dimensional model of the speed increasing planetary gear system of the semi-direct drive wind turbine. Motion pairs, drive and load of the model are added by ADAMS. Angular velocity change rule of the parts is obtained. The change rules of the mesh force of the planetary gears, ring and sun gear can be obtained through the dynamic simulation and analysis using the contact algorithm. These are useful to study the vibration and noise of the system.


Wind Energy ◽  
2014 ◽  
Vol 18 (4) ◽  
pp. 567-590 ◽  
Author(s):  
S. Struggl ◽  
V. Berbyuk ◽  
H. Johansson

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