scholarly journals A Comparison Study between Two MPPT Control Methods for a Large Variable-Speed Wind Turbine under Different Wind Speed Characteristics

Energies ◽  
2017 ◽  
Vol 10 (5) ◽  
pp. 613 ◽  
Author(s):  
Dongran Song ◽  
Jian Yang ◽  
Mei Su ◽  
Anfeng Liu ◽  
Yao Liu ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Control Methods ◽  
Comparison Study ◽  
Variable Speed ◽  
Variable Speed Wind Turbine

scholarly journals Load Mitigation and Optimal Power Capture for Variable Speed Wind Turbine in Region 2

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Saravanakumar Rajendran ◽  
Debashisha Jena
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Sliding Mode ◽  
Drive Train ◽  
Variable Speed ◽  
Terminal Sliding Mode ◽  
Static State ◽  
Variable Speed Wind Turbine ◽  
Power Capture ◽  
Speed Estimator

This paper proposes the two nonlinear controllers for variable speed wind turbine (VSWT) operating at below rated wind speed. The objective of the controller is to maximize the energy capture from the wind with reduced oscillation on the drive train. The conventional controllers such as aerodynamic torque feedforward (ATF) and indirect speed control (ISC) are adapted initially, which introduce more power loss, and the dynamic aspects of WT are not considered. In order to overcome the above drawbacks, modified nonlinear static state with feedback estimator (MNSSFE) and terminal sliding mode controller (TSMC) based on Modified Newton Raphson (MNR) wind speed estimator are proposed. The proposed controllers are simulated with nonlinear FAST (fatigue, aerodynamics, structures, and turbulence) WT dynamic simulation for different mean wind speeds at below rated wind speed. The frequency analysis of the drive train torque is done by taking the power spectral density (PSD) of low speed shaft torque. From the result, it is found that a trade-off is to be maintained between the transient load on the drive train and maximum power capture.

Simulating the Dynamic and Steady State Response of a Rotor Resistive Controlled 1.5 MW Variable Speed Wind Turbine

2010 ◽  
Author(s):  
Jared B. Garrison ◽  
Michael E. Webber
Keyword(s):  
Steady State ◽  
Wind Speed ◽  
Dynamic Response ◽  
Wind Turbine ◽  
Power Output ◽  
Pitch Angle ◽  
Maximum Power ◽  
Variable Speed ◽  
Wind Speeds ◽  
Variable Speed Wind Turbine

Currently, wind and solar technologies only generate 0.77% and 0.014% of the U.S. electricity consumption, respectively [1]. Though only a small portion of total U.S. electricity production, both sources have seen significant growth recently. For instance, Texas has more than quadrupled its installed wind capacity over the period from 2005–2009 with new installations totaling over 9400 MW [2, 3]. These two resources are globally available and have the potential to generate massive amounts of electricity. As the amount of installed wind turbines continues to grow, gaining better knowledge of their operation and their dynamic response to changing wind conditions is important to ensure their smooth integration and safe operation. The goal of this research is to analyze the dynamic and steady state operations of a 1.5 MW variable speed wind turbine that uses an external rotor resistive control mechanism. The addition of the external generator rotor resistance allows for adjustment of the generator slip and employs a feedback controller that maintains constant power output at all air velocities between the rated wind speed and cut-out wind speed. Using the electronic programming language PSCAD/EMTDC the model simulates the dynamic response to changing wind conditions, as well as the performance under all wind conditions. The first task of the model was to determine which blade pitch angle produces a maximum power output of 1.5 MW. A sweep was used where the simulation runs over the entire range of wind speeds for a selected pitch angle to find which speed resulted in maximum power output. This sweep was used for numerous blade pitch angles until the combination of wind speed and pitch angle at 14.4 m/s and −0.663°, respectively, resulted in a maximum power of 1.5 MW. The second task was to evaluate the model’s dynamic response to changes in wind conditions as well as steady state operation over all wind speeds. The dynamic response to an increase or decrease in wind speed is important to the safety and life expectancy of a wind turbine because unwanted spikes and dips can occur that increase stresses in the wind turbine and possibly lead to failure. In order to minimize these transient effects, multiple controllers were implemented in order to test each ones’ dynamic response to increasing and decreasing changes in wind velocity. These simulations modeled the characteristics of a variable-speed wind turbine with constant power rotor resistive control. First, through calibrating the model the design specifications of blade pitch and wind speed which yield the peak desired output of 1.5 MW were determined. Then, using the method of controlling the external rotor resistance, the simulation was able to maintain the 1.5 MW power output for all wind speeds between the rated and cutout speeds. Also, by using multiple controllers, the dynamic response of the control scheme was improved by reducing the magnitude of the initial response and convergence time that results from changes in wind speed. Finally, by allowing the simulation to converge at each wind speed, the steady state operation, including generator power output and resistive thermal losses, was characterized for all wind speeds.

Methods for Increasing Region 2 Power Capture on a Variable-Speed Wind Turbine

2004 ◽  
Vol 126 (4) ◽  
pp. 1092-1100 ◽  
Author(s):  
Kathryn E. Johnson ◽  
Lee J. Fingersh ◽  
Mark J. Balas ◽  
Lucy Y. Pao
Keyword(s):  
Wind Turbine ◽  
Maximum Energy ◽  
Control Methods ◽  
Variable Speed ◽  
Rotor Speed ◽  
Energy Capture ◽  
Control Scheme ◽  
Variable Speed Wind Turbine ◽  
Power Capture ◽  
Speed Fluctuations

The standard region 2 control scheme for a variable-speed wind turbine, τc=Kω2, has several shortcomings that can result in significant power loss. The first of these is that there is no accurate way to determine the gain K; modeling programs are not accurate enough to represent all of the complex aerodynamics, and these aerodynamics change over time. Furthermore, it is not certain whether the value of K used in the standard control even provides for the maximum energy capture under real-world turbulent conditions. We introduce new control methods to address these issues. First, we show in simulation that using smaller values of K than the standard can result in increased energy capture. Second, we give simulation results showing that an optimally tracking rotor control scheme can improve upon the standard scheme by assisting the rotor speed in tracking wind-speed fluctuations more rapidly. Finally, we propose an adaptive control scheme that allows for maximum power capture despite parameter uncertainty.

Continuous Variable Speed Wind Turbine: Transmission Concept and Robust Control

2000 ◽  
Vol 24 (3) ◽  
pp. 151-167 ◽  
Author(s):  
Moshe Idan ◽  
David Lior
Keyword(s):  
Control System ◽  
Robust Control ◽  
Wind Speed ◽  
Wind Turbine ◽  
Power Output ◽  
Energy Output ◽  
Variable Speed ◽  
Efficient Operation ◽  
Variable Speed Wind Turbine ◽  
Wide Range

This paper presents the theory and design of a novel hybrid mechanical-electrical variable speed wind turbine transmission, and discusses a robust control solution for optimal power output of the wind turbine equipped with such a transmission. The novel, planetary differential transmission would be driven by the variable speed rotor and controlled by a control system to ensure a constant speed of the main generator at a wide range of wind speed variations. Analysis shows that this would lead to an increase in the wind turbine energy output, estimated to be in the range of 15% to 20%, compared to a wind turbine with the same rotor and a fixed transmission. Using robust control design techniques, a single controller is synthesized for efficient operation over the entire anticipated wind speed range. The control system automatically varies the rotor speed to optimize its power output for slow wind speed variation and attenuates high frequency wind gust effects to reduce the resulting fatigue damage. Overall, the new concept provides a cost effective solution for variable speed wind turbine operation. The improved system performance is demonstrated using the results of a numerically simulated dynamic model of the proposed system.

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