Performance Characterization of a Wind Turbine Simulator for Grid Connected and Islanded Wind Turbine Operation

2007 ◽  
Author(s):  
Dan Zimmerle ◽  
Oliver Pacific ◽  
Nathan Howard
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Field Measurements ◽  
State University ◽  
Electrical Networks ◽  
Transmission Grid ◽  
Colorado State University ◽  
Grid Simulation ◽  
Field Information ◽  
The Individual

To better understand the effect of significant wind power production on distributed electrical networks, a Wind Turbine Simulator (WTS) was incorporated into the Grid Simulation Laboratory (GSL) at Colorado State University. This paper discusses the development of the engine controls, gain tuning and response matching to field measurements of wind turbines. Response was characterized while connected to the transmission grid, similar to the field information, using a series of transient events gleaned from field information. Transients caused by breaker events, which emulate connecting or disconnecting the individual wind turbines, were also considered. While overall correlation between commanded and actual power output was strong, several limitations were identified and are described.

scholarly journals Experimental and simulation-based analysis of asymmetrical spherical roller bearings as main bearings for wind turbines

2021 ◽  
Author(s):  
Amin Loriemi ◽  
Georg Jacobs ◽  
Sebastian Reisch ◽  
Dennis Bosse ◽  
Tim Schröder
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Measurement Data ◽  
Contact Angles ◽  
Suspension System ◽  
Roller Bearings ◽  
Axial Forces ◽  
Wind Turbine System ◽  
Bearing Life ◽  
The Individual

AbstractSymmetrical spherical roller bearings (SSRB) used as main bearings for wind turbines are known for their high load carrying capacity. Nevertheless, even designed after state-of-the-art guidelines premature failures of this bearing type occur. One promising solution to overcome this problem are asymmetrical spherical roller bearings (ASRB). Using ASRB the contact angles of the two bearing rows can be adjusted individually to the load situation occurring during operation. In this study the differences between symmetrical and asymmetrical spherical roller bearings are analyzed using the finite element method (FEM). Therefore, FEM models for a three point suspension system of a wind turbine including both bearings types are developed. These FEM models are validated with measurement data gained at a full-size wind turbine system test bench. Taking into account the design loads of the investigated wind turbine it is shown that the use of an ASRB leads to a more uniform load distribution on the individual bearing rows. Considering fatigue-induced damage an increase of the bearing life by 62% can be achieved. Regarding interactions with other components of the rotor suspension system it can be stated that the transfer of axial forces into the gearbox is decreased significantly.

Study on a global control strategy for rotation speed with different work states in variable-speed constant-frequency wind turbines

2011 ◽  
Vol 225 (7) ◽  
pp. 968-976 ◽  
Author(s):  
G Zheng ◽  
H Xu ◽  
X Wang ◽  
J Zou
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Control Strategy ◽  
Control Strategies ◽  
Stable Operation ◽  
Constant Frequency ◽  
Global Control ◽  
Control Rules ◽  
The Individual ◽  
And Control

This paper studies the operation of wind turbines in terms of three phases: start-up phase, power-generation phase, and shutdown phase. Relationships between the operational phase and control rules for the speed of rotation are derived for each of these phases. Taking into account the characteristics of the control strategies in the different operational phases, a global control strategy is designed to ensure the stable operation of the wind turbine in all phases. The results of simulations are presented that indicate that the proposed algorithm can control the individual phases when considered in isolation and also when they are considered in combination. Thus, a global control strategy for a wind turbine that is based on a single algorithm is presented which could have significant implications on the control and use of wind turbines.

An Experimental Study on the Effects of Wake Interference on the Performances of Wind Turbines Over Complex Terrains

2012 ◽  
Author(s):  
Hui Hu ◽  
Ahmet Ozbay ◽  
Wei Tian ◽  
Zifeng Yang
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Flow Characteristics ◽  
Field Measurements ◽  
Wake Interference ◽  
Baseline Case ◽  
Power Yield ◽  
Power Outputs

An experimental study was conducted to investigate the interferences of wind turbines sited over hilly terrains in order to elucidate underlying physics to explore/optimize design paradigms of wind turbines sited over complex terrains for higher power yield and better durability. The experiments were conducted in a large wind tunnel with of wind turbine models sited over a flat terrain (baseline case) and a 2D-ridge with non-homogenous atmospheric boundary layer winds. In addition to measuring dynamic wind loads (both forces and moments) and the power outputs of the wind turbine models, a high-resolution digital Particle Image Velocimetry (PIV) system was used to conduct detailed flow field measurements to quantify the flow characteristics of the surface winds and wake interferences among multiple wind turbines over flat (baseline case) and complex terrains. The detailed flow field measurements were correlated with the wind load measurements and power outputs of the wind turbine models to elucidate the underlying physics associated with turbine power generation and fatigue loads acting on the wind turbines.

scholarly journals Exploring the Causes of Power-Converter Failure in Wind Turbines based on Comprehensive Field-Data and Damage Analysis

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 593 ◽  
Author(s):  
Katharina Fischer ◽  
Karoline Pelka ◽  
Sebastian Puls ◽  
Max-Hermann Poech ◽  
Axel Mertens ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Service Providers ◽  
Field Measurements ◽  
Power Converter ◽  
Damage Analysis ◽  
Human Errors ◽  
Die Attach ◽  
Research Initiative ◽  
Maintenance Service

Power converters are among the most frequently failing components of wind turbines. Despite their massive economic impact, the actual causes and mechanisms underlying these failures have remained in the dark for many years. In view of this situation, a large consortium of three research institutes and 16 companies, including wind-turbine and component manufacturers, operators and maintenance-service providers has joined forces to identify the main causes and driving factors of the power-converter failures in wind turbines to create a basis for effective remedial measures. The present paper summarizes and discusses the results of this research initiative, which have been achieved through the evaluation of converter-specific failure and operating data of a large and diverse worldwide wind-turbine fleet, field measurements as well as post-mortem investigation of returned converter components. A key conclusion of the work is that the thermal-cycling induced fatigue of bond-chip contacts and die-attach solder, which is a known issue in other fields of power-electronics applications and which has been widely assumed to be the principle damage mechanisms also in wind turbines, is no relevant contributor to the observed converter failures in this application. Instead, the results indicate that environmental factors such as humidity and contamination but also design and quality issues as well as human errors play an important part in the incidence of these failures.

scholarly journals Effect of individual blade pitch angle misalignment on the remaining useful life of wind turbines

2021 ◽  
Author(s):  
Matthias Saathoff ◽  
Malo Rosemeier ◽  
Thorsten Kleinselbeck ◽  
Bente Rathmann
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Empirical Data ◽  
Pitch Angle ◽  
Remaining Useful Life ◽  
Good Representation ◽  
Data Set ◽  
Useful Life ◽  
The Individual ◽  
Blade Pitch Angle

Abstract. An empirical data set of laser-optical pitch angle misalignment measurements on wind turbines was analyzed, and showed that 38 % of the turbines have been operating outside the accepted aerodynamic imbalance range. This imbalance results from deviations between the working pitch angle and the design angle set point. Several studies have focused on the consequences of this imbalance for the annual energy production (AEP) loss and mention a possible decrease in fatigue budget, i.e., remaining useful life (RUL). This research, however, quantifies the effect of the individual blade pitch angle misalignment and the resulting aerodynamic imbalance on the RUL of a wind turbine. To this end, several imbalance scenarios were derived from the empirical data representing various individual pitch misalignment configurations of the three blades. As the use case, a commercial 1.5 MW turbine was investigated which provided a good representation of the sites and the turbine types in the empirical data set. Aeroelastic load simulations were conducted to determine the RUL of the turbine components. It was found that the RUL decreased in most scenarios, while the non-rotating wind turbine components were affected most by an aerodynamic imbalance.

scholarly journals Effect of individual blade pitch angle misalignment on the remaining useful life of wind turbines

2021 ◽  
Vol 6 (5) ◽  
pp. 1079-1087
Author(s):  
Matthias Saathoff ◽  
Malo Rosemeier ◽  
Thorsten Kleinselbeck ◽  
Bente Rathmann
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Empirical Data ◽  
Pitch Angle ◽  
Remaining Useful Life ◽  
Good Representation ◽  
Data Set ◽  
Useful Life ◽  
The Individual ◽  
Blade Pitch Angle

Abstract. An empirical data set of laser-optical pitch angle misalignment measurements on wind turbines was analyzed, and showed that 38 % of the turbines have been operating outside the accepted aerodynamic imbalance range. This imbalance results from deviations between the working pitch angle and the design angle set point. Several studies have focused on the consequences of this imbalance for the annual energy production (AEP) loss and mention a possible decrease in fatigue budget, i.e., remaining useful life (RUL). This research, however, quantifies the effect of the individual blade pitch angle misalignment and the resulting aerodynamic imbalance on the RUL of a wind turbine. To this end, several imbalance scenarios were derived from the empirical data representing various individual pitch misalignment configurations of the three blades. As the use case, a commercial 1.5 MW turbine was investigated, which provided a good representation of the sites and the turbine types in the empirical data set. Aeroelastic load simulations were conducted to determine the RUL of the turbine components. It was found that the RUL decreased in most scenarios, while the non-rotating wind turbine components were affected most by an aerodynamic imbalance.

Effect of Flow Inclination on Wind Turbine Performance

2012 ◽  
Author(s):  
C. Tsalicoglou ◽  
S. Barber ◽  
N. Chokani ◽  
R. S. Abhari
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Field Measurements ◽  
Wake Flow ◽  
Test Facility ◽  
Power Coefficient ◽  
Incoming Flow ◽  
Turbine Performance ◽  
The Impact ◽  
Blade Element

This work examines the effect of flow inclination on the performance of a stand-alone wind turbine and of wind turbines operating in the wakes of upstream turbines. The experimental portion of this work, which includes performance and flow-field measurements, is conducted in the ETH dynamically-scaled wind turbine test facility, with a wind turbine model that can be inclined relative to the incoming flow. The performance of the wind turbine is measured with an in-line torque-meter and a 5-hole steady-state probe is used to detail the inflow and wake flow of the turbine. Measurements show that over a range of tip-speed ratios of 4–7.5, the power coefficient of a wind turbine with an incoming flow of 15-degrees inclination decreases on average by 7% relative to the power coefficient of a wind turbine with a non-inclined incoming flow. Flowfield measurements show that the wake of a turbine with an inclined incoming flow is deflected; the deflection angle is approximately 6-degrees for an incoming flow with 15-degrees inclination. The measured wake profiles are used as inflow profiles for a Blade Element Momentum code in order to quantify the impact of flow inclination on the performance of downstream wind turbines. In comparison to the case without inclination in the incoming flow, the combined power output of two aligned turbines with incoming inclined flow decreases by 1%, showing that flow inclination in complex terrain does not significantly reduce the energy production.

Support Structure Reliability of Offshore Wind Turbines Utilizing an Adaptive Response Surface Method

2010 ◽  
Author(s):  
Sebastian Tho¨ns ◽  
Michael H. Faber ◽  
Werner Ru¨cker
Keyword(s):  
Wind Turbine ◽  
Reliability Analysis ◽  
Response Surface ◽  
Wind Turbines ◽  
Adaptive Response ◽  
Offshore Wind ◽  
Limit States ◽  
Support Structure ◽  
Prediction Variance ◽  
The Individual

This paper focuses on a reliability analysis of an offshore wind turbine support structure which is part of an assessment and monitoring framework for wind turbines in operation. The reliability analysis builds upon structural, loading, limit state and uncertainty models comprising design, production and erection data. This model basis facilitates the reliability analysis of the ultimate, the fatigue and the serviceability limit states utilizing stochastic finite elements. The complexity of the individual models dictates an efficient solution scheme for the reliability analysis. Such an algorithm is developed in the present paper consisting of an adaptive response surface algorithm and an importance sampling Monte-Carlo algorithm. The response surface algorithm is based on predetermined experimental designs and facilitates the adjustment of design parameters for an optimized prediction variance in the design point region. Approaches for the consideration of multiple design points and the augmentation of the design for reduction of the prediction variance are introduced. In this paper, a reliability analysis for a tripod support structure of a Multibrid M5000 wind turbine is performed. A comparison with the target reliabilities specified in DIN EN 1990 (2002) shows that the requirements are fully met. However, the consideration of system reliability leads to the conclusion that at the end of the service life there is a significant probability of fatigue damages. The quantification of the reliability for the individual structural components for all limit states facilitates an identification of sensitive components. The results of this study can support the targeted application of monitoring systems, the optimization of the support structures and additionally highlight the need for criteria to the systems reliability.

scholarly journals A Comparison of Edge Detectors in the Framework of Wake Pattern Modeling for Wind Turbines

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Yanjun Yan ◽  
James Z. Zhang ◽  
Hayrettin Bora Karayaka
Keyword(s):  
Power Generation ◽  
Wind Speed ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Linear Prediction ◽  
Edge Detector ◽  
Wake Effect ◽  
Edge Detectors ◽  
The Individual

To monitor wind turbine health, wind farm operators can take advantage of the historical SCADA (supervisory control and data acquisition) data to generate the wake pattern beforehandfor each wind turbine, and then decide in real time whether observed reduction in power generation is due to wake or true faults. In our earlier efforts, we proposed an effective wakepattern modeling approach based on edge detector using Linear Prediction (LP) with entropy-thresholding, and smoothing using Empirical Mode Decomposition (EMD) on the windspeed difference plots. In this paper, we compare the LP based edge detector with two other predominant edge detectors, Sobel and Canny edge detectors, to quantitatively justifythe appropriateness and effectiveness of the LP based edge detector in wind turbine wake pattern analysis. We generate a fused wake model for the turbine of interest with multiple neighboring turbines, and then analyze the wake effect on turbine power generation. With a fused wake pattern, we do not need to identify the individual source of wake any more. Weexpect that wakes cause reduced wind speed and hence reduced power generation, but we have also observed from the SCADA data that the wind turbines in wake zones tend to overreact when the wind speed is not yet close to the highwind- shut-down threshold, which causes further power generation loss.

scholarly journals A multi-purpose lifting-line flow solver for arbitrary wind energy concepts

2021 ◽  
Author(s):  
Emmanuel Branlard ◽  
Ian Brownstein ◽  
Benjamin Strom ◽  
Jason Jonkman ◽  
Scott Dana ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Field Measurements ◽  
Vertical Axis ◽  
Future Research ◽  
Horizontal Axis Wind Turbine ◽  
Flow Solver ◽  
Wind Turbine Aerodynamics ◽  
Vertical Axis Wind Turbines ◽  
Lifting Surfaces

Abstract. In this work, we extend the AeroDyn module of OpenFAST to be able to support arbitrary collections of wings, rotors and towers. The new standalone AeroDyn driver supports arbitrary motions of the lifting-surfaces and complex turbulent inflows. We describe the features and updates necessary for the implementation of the new AeroDyn driver. We present different case studies of the driver to illustrate its application to concepts such as: multi-rotors, kites, or vertical axis wind turbines. We perform verification and validation of some of the new features using the following test cases: an elliptical wing, a horizontal axis wind turbine, and a 2D and 3D vertical axis wind turbines. The wind turbine simulations are compared to field measurements. We use this opportunity to point out some limitations of current models and highlight areas which we think should be the focus of future research in wind turbine aerodynamics.

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