• New & Renewable Energy
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• v.9 no.1
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• pp.12-16
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• 2013

The nacelle anemometer mounted behind the blade roots of a wind turbine measures distorted wind speed comparable with free-stream wind because of the wake effects caused dependent upon the operation of the wind turbine and the rotation of its blades. The field campaign was carried out to measure free-stream wind speed at a height identical to the height of the nacelle anemometer by deploying a ground-based remote-sensing equipment, LIDAR. It is derived that a third-order polynomial equation for correcting wind speed measured by the nacelle anemometer to undistorted free-stream wind speed incident to a wind turbine. It is anticipated that the derived correction equation enables wind speed measured by the nacelle anemometer to be used as a precise input for a wind turbine performance test and for developing an active control logic.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.19-26
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• 2011

We are carried out power performance testing for 3MW wind turbine system at Je-ju wind turbine testing Site and analyzed measured data which was stored through monitoring system. In this paper, we described the power performance testing results and analyzed an uncertainty of measured data sets. The power curve with measured power data is closely coincide with designed power curve except for the low wind speed sections(4m/s~7m/s) and the annual energy production which is given Ray leigh distribution was included with 1.5~5.9% of uncertainty in the wind speed region as 4~11m/s. Although the deviation of curve between measured power and designed power is high, the difference of annual energy production is low in the low wind speed region.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.36-36
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• 2000

The paper presents a speed control algorithm for a full pitch-controlled wind turbine system. Torque of a blade generated by wind energy is non-linear function of a wind speed, angular velocity, and pitch angle of the blade. The design of a cor_troller, in general, is performed by linearizing the torque in the vicinity of a operating point assuming the angular velocity of the blade is constant. For speed control, however, the angular velocity is no longer a constant, so that linearization of the torque in terms of a wind speed and pitch angle is impossible. In this study, a reference pitch model is derived in terms of a wind speed, angular velocity, and pitch angle, which makes it possible to design a controller without linearizing the non-linear torque model of the blade. The validity of the algorithm is demonstrated with the results produced through sets of experiments.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.424-428
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• 2004

A wind turbine system converts wind energy into electric energy, the system operated under normal environmental conditions. In case of particular turbulent wind flow such as typhoon, hurricane etc, the control of a blade used to a yaw control and a pitch control method. A small wind turbine has not a speed control system to only a manual tail safety brake. This paper shows a automatic tail safety brake controller based on feedback control using wind velocity. The controller composed of wired motor, relay system, steel wired motor him down a perpendicular to wind flow and then the blade speed reduced high to zero. The operation of automatic tail safety controller verified by manual test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.92-99
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• 2016

A wind turbine is controlled for the purpose of obtaining the maximum power below its rated wind speed. Among the methods of obtaining the maximum power, TSR (Tip Speed Ratio) optimal control and P&O (Perturbation and Observation) control are widely used. The P&O control algorithm using the turbine power and rotational speed is simple, but its slow response is a weak point. Whereas TSR control's response is fast, it requires the precise wind speed. A method of measuring or estimating the wind speed is used to obtain a precise value. However, estimation methods are mostly used, because it is difficult to avoid the blade interference when measuring the wind speed near the blades. Neural networks and various numerical methods have been applied for estimating the wind speed, because it involves an inverse problem. However, estimating the wind speed is still a difficult problem, even with these methods. In this paper, a new method is introduced to estimate the wind speed in the wind-power graph by using the turbine power and rotational speed. Matlab/Simulink is used to confirm that the proposed method can estimate the wind speed properly to obtain the maximum power.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.337-343
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• 2012

NREL(National Renewable Energy Laboratory) Baseline controller conduct using method proposed RISO National Laboratory in Region 3. which designed the blade-pitch control system using a single degree-of-freedom model of the wind turbine. Idealized PID-Controlled rotor-speed error will respond as a second-order system with the natural frequency and damping ratio. RISO proposed specific natural frequency(=0.6 rad/s) and damping ratio(=0.7). If specific Eigen value apply to NREL 5 MW wind turbine, differ with pitch respond for simulation results of RISO report. Variation of specific eigen value investigate performance of NREL 5 MW wind turbine.

• Journal of Power Electronics
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• v.10 no.6
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• pp.733-738
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• 2010

This paper deals with a ride-through technique for permanent-magnet synchronous generator (PMSG) wind turbine systems using energy storage systems (ESS). A control strategy which consists of current and power control loops for the energy storage systems is proposed. By increasing the generator speed, some portion of the turbine power can be stored in the system inertia. Therefore, the required energy capacity of the ESS can be decreased, which results in a low-cost system. In addition, the power fluctuations due to wind speed variations can be smoothened by controlling the ESS appropriately. The effectiveness of the proposed method is verified not only by the simulation results for a 2[MW] PMSG wind turbine system, but also by the experiment results for a reduced-scale turbine simulator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.597-607
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• 2014

This paper proposes active power control and frequency support control schemes of wind turbine generation system by using modified Maximum Power Point Tracking(MPPT) of Permanent Magnet Synchronous Generator(PMSG). Most wind turbine generation system is completely decoupled from the power system and power output control with pitch control. According to the frequency deviation, however, MPPT control can not contribute to the frequency change of the power system due to its active power output control. For solving this, the de-loaded(DL) control scheme is constructed for the frequency support control, which is based on applying the active power output control in the rotor speed control of PMSG. The rotor speed by used in the proposed DL control scheme is increased more than the optimal rotor speed of MPPT, and then this speed improvement increases the saved kinetic energy(KE). In order to show the effectiveness of the proposed control scheme, the case studies have been performed using the PSCAD/EMTDC. The results show that the proposed active power output control scheme(DL control and KE discharge control) works properly and the frequency response ability of the power system can be also improved with the frequency support of wind farm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.951-958
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• 2008

This paper describes development of hardware simulator for the PMSG wind power system, which was designed considering wind characteristic, blade characteristic and blade inertia compensation. The simulator consists of three major parts, such as wind turbine model using induction motor, PMSG generator, converter-inverter set. and control system. The turbine simulator generates torque and speed signals for a specific wind turbine with respect to given wind speed. This torque and speed signals are scaled down to fit the input of 2kW PMSG. The PMSG-side converter operates to track the maximum power point, and the grid-side inverter controls the active and reactive power supplied to the grid. The operational feasibility was verified by computer simulations with PSCAD/EMTDC, and the implementation feasibility was confirmed through experimental works with a hardware set-up.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.349-359
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• 2019

This paper introduces a wind turbine simulation system based on the IEC 61400-25 standard to simulate different kinds of wind turbines. A unified communication protocol was required for monitoring and control of wind turbines, because manufacturers had used their own protocols for their turbines. As a result of such an effort, the international standard IEC 61400-25 was established. To implement the schema of IEC 61400-25, the IEC61850 SCL was modified and applied to the simulation system, which enabled the system to be compatible with heterogeneous wind turbine information models. The developed simulation system can be used for interoperability tests with a new type of wind turbine information model.