• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.31-40
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• 2012

This paper introduces a methodology for NREL 5MW wind turbine, which is the variable speed and variable pitch(VSVP) control system. This control strategy maximizes the power extraction capability from the wind in the low wind speed region and regulates the wind turbine power as the rated one for the high wind speed region. Also, pitch control efficiency is raised by using pitch scheduling.Torque schedule is made of torque table depending on the rotor speed. Torque control is used for vertical region in a torque-rotor speed chart. In addition to these, mechanical loads reduction using a drive train damper and exclusion zone on a torque schedule is tried. The NREL 5MW wind turbine control strategy is comprised by the generator torque and blade pitch control. Finally, proposed control system is verified through GH Bladed simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.1-9
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• 2004

In this paper, an efficient modeling method of Horizontal-Axis Wind Turbine(HAWT) system is proposed. This method Is based on representing a HAWT system as a multi-body system with several rigid bodies i.e. rotor blade, low/high speed shaft, gear system, md generator. Also, simulation software WINSIM is developed to evaluate performance of wind turbine system. Simulation results show that the proposed modeling method and simulation software are efficient and reliable.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.524-531
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• 2013

This work aims at developing a RTB (Rotor Track and Balance) system to alleviate imbalances originating from various sources encountered during blade manufacturing process and environmental factors. The analytical RTB model is determined based on the linear regression analysis to relate the RTB adjustment parameters and their track and vibration results. The model is validated using the flight test data of a full helicopter. It is demonstrated that the linearized model has been correlated well with the test data. A hybrid optimization problem is formulated to find the best solution of the RTB adjustment parameters using the genetic algorithm combined with the PSO (Particle Swarm Optimization) algorithm. The optimization results reveal that both track deviations and vibration levels under various flight conditions become decreased within the allowable tolerances.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.41-47
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• 2010

There are many unbalanced models such as helicopter's rotor blades, small-sized precision motor in industrial applications. In the real products, their gravity center usually does not accord with the desired gravity center. If the deviation is large between them, it can be a major cause of vibration and noise as the part of model rotate. Therefore the gravity center in the rotational parts should be controlled properly because of static and dynamic balancing of the parts. In the research, the rotor blade of unmanned helicopter has been selected to obtain the high quality of balancing. In order to achieve the purpose, measuring system has been developed. In the system applied principle is three point weighting method, which is one of the Multiple-point Weighting Method. It has circle fitting for compensation of machining error, after measuring the values. From this study, the results showed that the proposed measurement procedure gives reliable and precise gravity center.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.156-162
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• 2008

The static aeroelastic analysis of composite hingeless rotor blades in hover was performed using free-wake method. Large deflection beam theory was applied to analyze blade motions as a one-dimension beam. Anisotropic beam theory was applied to perform a cross-sectional analysis for composite rotor blades. Aerodynamic loads were calculated through a three-dimensional aerodynamic model which is based on the unsteady vortex lattice method. The wake geometry in hover was described using a time-marching free-wake method. Numerical results of the steady-state deflections for the composite hingeless rotor blades were presented and compared with those results based on two-dimensional quasi-steady strip theory and prescribed wake method. It was shown that wakes affect the steady-state deflections.

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.9-16
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• 2015

In order to support various studies for assessment of onshore and offshore wind turbine system including foundations, the land-based version of 2MW PMSG direct drive wind turbine has been analyzed using HAWC2 that account for the coupled dynamics of the wind inflow, elasticity, and controls of the turbine. this work presents the steady-state response of the system and natural frequency of the first thirteen structure turbine modes as a function of wind speed. Rotor, generator speeds, pitch angle, power production, thrust force, deflections of tower and blade are compared for one case below and one case above the rated wind speed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.91-97
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• 2007

This paper presents a pitch angle controller of a grid-connected wind turbine system for extracting maximum power from wind and implements a modeling and simulation of the wind turbine system on MATLAB/Simulink. It discusses the maximum power control algorithm for the wind turbine and presents, in a graphical form, the relationship of wind turbine output, rotor speed, and power coefficient with wind speed when the wind turbine is operated under the maximum power control algorithm. The objective of pitch angle control is to extract maximum power from wind and is achieved by regulating the blade pitch angle during above-rated wind speeds in order to bypass excessive energy in the wind. Case studies demonstrate that the pitch angle control is carried out to achieve maximum power extraction during above-rated wind speeds and effectiveness of the proposed controller would be satisfactory.

• New & Renewable Energy
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• v.9 no.1
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• pp.44-50
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• 2013

In order to analyze the characteristics of tidal current power generation system, we measured the output power according to the stream velocity by a water tunnel system and a simulation in MATLAB/Simulink. The water tunnel system consisted of impeller tidal flow transducer and PMSG with rotor in the water. The simulation consisted of PMSG, the tidal current turbine, and back-to-back converter. Also, we simulated the characteristics of output power according to the change of blade length and angular velocity.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.170-173
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• 2002

A variable speed wind turbine simulator is designed and implemented for the simulation of wind power generation system. The control algorithm decides the shaft torque delivered to generator taking into consideration the wind speed, the generator rpm, and the rotor blade inertia. It is shown that the proposed control algorithm can emulate the dynamic behavior of actual wind turbine through simulations and experimental.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.235-237
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• 2007

최근 신재생 에너지로 풍력 발전 시스템이 중요시 되고 있다. 이에 본 논문에서는 풍력발전 시스템의 Wind Turbine System을 영구자석형 동기기를 이용하여 시뮬레이션 모델을 구현하였다. 시뮬레이션 모델은 회전자 모델, MPPT 알고리즘, 영구자석형 동기기(PMSM) 등으로 구성되어있다. Wind Blade Rotor의 유체역학적 특성 및 가감속 제어전략을 이용하여 Wind Turbine System의 특성을 시뮬레이션 할 수 있도록 하였다. 본 연구 결과는 이후 영구자석형 동기기를 이용한 풍력발전기의 기초 자료로서 이용될 수 있을 것으로 기대된다.