• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.467-470
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• 2009

Variable loads along the drive-train are attributed to frequent failures of gears, bearings, and other components. Wind parameters cannot be controlled and therefore any turbine load-reducing remedies must be established based on proper insights into the wind-turbine interactions. A novel control concept to performance optimization of wind turbines is presented. This proposed concept is based on analysis of the turbine status reflected in the SCADA data. Modern computational techniques are used to optimize performance of a wind turbine from tree basic perspectives: drive-train, power output, and power quality. The proposed approach demonstrates that gains in the metrics representing the three perspectives and the corresponding control goals can be significantly improved for any wind turbine. The solution is applicable different turbine types operating in different wind regimes, e.g., winds of different speeds and variability. Simple and transparent parameters allow an operator to determine a balance between the operations and maintenance, technical, business objectives. The proposed modeling framework was embedded in software. The software tool has been tested on the data collected from 1.5 MW wind turbines.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.603-605
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• 1999

In this paper, the aspects on modeling and control of an existing wind turbine are discussed. When designing control for variable-speed wind turbine, one deals with highly resonant, nonlinear dynamic systems subject to random excitation, i.e. wind turbulence. This requires good knowledge of the dynamics to be controlled. This paper describes an mathematical modeling of wind turbines with emphasis on control design for an existing wind turbine.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.3
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• pp.40-46
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• 1999

Aerodynamic performance and starting characteristic of wind turbine blade are important factors that determine the whole system as rated power, operating method, etc. Therefore, starting characteristic according to aerodynamic performance, wind speed and blade pitch angle should be examined while wind turbine blade is designed. In this study, the aerodynamic analysis program of 750㎾ class horizontal axis wind turbine blade was developed and to certify this program, the aerodynamic performance of the commercialized blade was analyzed with it. The analysis result was corresponding to the value presented from manufacturer. And the starting analysis program was developed on the basis of the developed aerodynamic analysis program and starting analysis was performed. As a result, it was confirmed that variable speed operation and variable pitch control are profitable to wind turbine used in low wind speed as our country.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.8
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• pp.935-944
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• 2015

This study performs the dynamic modeling and the simulation of variable speed wind power system and implements the models of wind speed, wind turbine & PMSG, and MPPT & pitch control as well. The simulation of wind turbine was performed by using the power coefficient and other simulation parameters which were extracted with reference to the commercial 5MW class wind turbine data. As the result of this simulation, MPPT control is confirmed, maintaining the maximum power coefficient as far as the rated speed 12[m/s]. Over 12[m/s] wind speed, this wind power system makes it possible to keep the stable output by controlling the pitch angle.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.69-79
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• 2011

This paper proposes a new fuzzy speed control method based on Takagi-Sugeno fuzzy method of permanent magnet synchronous generators(PMSM) for variable-speed wind turbine systems. The proposed fuzzy speed controller consists of the control terms that compensate for the nonlinearity of PMSG and the control terms that stabilize the error dynamics. The conditions are derived for the existence of the proposed speed controller, and the gain matrices of the controller are given. The proposed control method can guarantee that the PMSG can effectively track the speed reference which is calculated through the MPPT control and can reduce the fluctuations of the generated power under even fast random wind conditions. To verify the performance of the proposed fuzzy speed controller, the simulation results are demonstrated.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.366-369
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• 2007

This paper presents the general results of the conceptual design of a 3MW class offshore wind turbine named WinDS 3000 under development. In WinDS 3000, an integrated drive train design, three stage gearbox and permanent magnet generator (PMG) with fully rated converters have been introduced. A pitch regulated variable speed power control with individual pitch control has been adopted to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. Through the introduction of WinDS 3000, it is expected that helpful to understanding of the development status of 3MW offshore wind turbine.

• Journal of Energy Engineering
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• v.12 no.4
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• pp.309-319
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• 2003

The main purpose of this paper is to present a simulation model for assessing the impacts of a variable speed wind turbine (VSWT) on the distribution network and perform a simulation analysis of volt-age profiles and harmonics along the wind turbine installed feeder using the presented model. The modeled wind energy conversion system consists of a fixed pitch wind turbine and a permanent-magnet synchronous generator, in which a controllable power electronics inverter performs variable speed operation and reactive power output control. Impact analysis on voltage profiles and harmonics of a VSWT-installed distribution feeder is addressed and simulated in terms of steady state and dynamic behaviors. Various capacities and different modes of variable speed wind turbines are simulated and investigated. Case studies demonstrate how feeder voltages are influenced by capacity and control modes of wind turbines and changes in wind speed under various network conditions, and show harmonic impacts on the feeder. Modeling and simulation analysis is based on PSCAD/EMTDC a software package.

• Journal of Power Electronics
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• v.18 no.1
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• pp.195-203
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• 2018

In the variable speed Wind Turbine based on ElectroMagnetic Coupler (WT-EMC), a synchronous generator is coupled directly to the grid. Therefore, like conventional power plants, WT-EMC is able to inherently support grid frequency. However, due to the reduced inertia of the synchronous generator, WT-EMC is expected to be controlled to increase its output power in response to a grid frequency drop to support grid frequency. Similar to the grid frequency support control of Type 3 or Type 4 wind turbine, inertial control and droop control can be used to calculate the WT-EMC additional output power reference according to the synchronous generator speed. In this paper, an experimental platform is built to study the grid frequency support from WT-EMC with inertial control and droop control. Two synchronous generators, driven by two induction motors controlled by two converters, are used to emulate the synchronous generators in conventional power plants and in WT-EMCs respectively. The effectiveness of the grid frequency support from WT-EMC with inertial control and droop control responding to a grid frequency drop is validated by experimental results. The selection of the grid frequency support controller and its gain for WT-EMC is analyzed briefly.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.11
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• pp.753-759
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• 2004

This paper presents a modeling and simulation of a fuzzy controller for maximum power extraction of a grid-connected wind energy conversion system with a link of a rectifier and an inverter. It discusses the maximum power control algorithm for a wind turbine and proposes, in a graphical form, the relationships of wind turbine output, rotor speed, power coefficient, tip-speed ratio with wind speed when the wind turbine is operated under the maximum power control. The control objective is to always extract maximum power from wind and transfer the power to the utility by controlling both the pitch angle of the wind turbine blades and the inverter firing angle. Pitch control method is mechanically complicated, but the control performance is better than that of the stall regulation method. The simulation results performed on MATLAB will show the variation of generator's rotor angle and rotor speed, pitch angle, and generator output.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.4
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• pp.396-402
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• 2010

In this paper the principles and structure of a WTS (Wind Turbine Simulator) are described. The proposed WTS is a versatile system specially designed for the purpose of developing and testing new control strategies for wind energy conversion systems. The simulator includes two sub-systems; a torque controller which controls a 3-phase induction motor in order to simulate the wind turbine and wind speed generator which can simulate an actual wind speed. In order to make the proposed system working in real-time, two sub-systems are incorporated into one simulink block by using Real-time workshop. The performance of the proposed system is verified by considering various wind speeds.