• 한국해양공학회지
• /
• 제23권5호
• /
• pp.25-31
• /
• 2009

The most important component of wind turbine is rotor blades. The developing method of wind turbine was focused on design of rotor blade. By the way, the design of a rotating body is more decisive process in order to adjust the performance of wind turbine. For instance, the design allows the designer to specify the wind characteristics derived by topographical map. The iterative solver is then used to adjust one of the selected inputs so that the desired rotating performance which is directly related to power generating capacity and efficiency is achieved. Furthermore, in order to save the money for manufacturing the rotor blades and to decrease the maintenance fee of wind power generation plant, while decelerating the cut-in speed of rotor. Therefore, the design and manufacturing of rotating body is understood as a substantial technology of wind power generation plant development. The aiming of this study is building-up the profitable approach to designing of rotating body as a system for the wind power generation plant. The process was conducted in two steps. Firstly, general designing and it’s serial testing of rotating body for voltage measurement. Secondly, the serial test results above were examined with the CFD code. Then, the analysis is made on the basis of amount of electricity generated by rotor-blades and of cut-in speed of generator.

• KIEAE Journal
• /
• 제15권1호
• /
• pp.155-160
• /
• 2015

The annual average of energy sources is continuously increasing at a rate of 5.8%, and particularly, the power generation proportion of new/renewable energy is increasing significantly. Furthermore, South Korea has established a national energy master plan for 2008-2030 and is aiming at obtaining approximately 11% of total energy production from the wind turbine sector. Although offshore wind turbines are similar to wind turbines installed on land, they require materials with excellent dynamic properties and durability to prevent damage due to seawater at the lower parts and connecting parts. The lower parts of wind turbines are submerged in seawater, and the upper and lower parts are connected by filling the connecting part with grout. This paper describes the test results of the process of determining the mix ratios to develop ultra-high grout for offshore wind turbines. There is virtually no relevant technology regarding grout for offshore wind turbines in South Korea that can be referenced for the process of determining the mix ratios. Therefore, tests were conducted for determining compression strength, elastic modulus, flexural strength, density, constructability (floor test), and early strength by referencing a high-performance grout produced in South Korea, and the mixing process for achieving the goal strengths was described using the Korean Industrial Standards (KS) as the reference.

• 한국산학기술학회논문지
• /
• 제15권12호
• /
• pp.7451-7458
• /
• 2014

본 논문에서는 독립된 풍력 복합발전 시스템을 대상으로 시스템의 모델링과 다양한 환경에서 체계적으로 동작시키기 위한 멀티에이전트 기반의 제어방법을 제안한다. 멀티에이전트 제어는 풍력발전기, 디젤발전기, 배터리, 부하로 구성되는 새로운 형식의 하이브리드 제어방법이고, 풍속과 배터리의 충전상태에 따라 풍력 복합발전 시스템의 운전은 14개의 모드로 나누어 수행된다. 시뮬레이션 성능평가를 통해 제안된 알고리즘이 독립된 풍력 복합발전 시스템에서 다양한 풍속변화가 존재하는 경우에도 효율적으로 운전될 수 있음을 보여준다.

• 조명전기설비학회논문지
• /
• 제22권8호
• /
• pp.18-25
• /
• 2008

본 논문은 HATLAB/Simulink에서 계통연계 풍력발전시스템의 특성해석을 위한 모델링을 제안하여 시뮬레이션을 수행한다. 이를 위해 풍속의 변화에 따른 발전기의 출력제어를 위해 피치제어를 수행하며, 연계변압기의 결선방법에 따른 고장전류의 변화를 살펴봄으로 하여 연계변압기의 결선방법과 고장전류와의 상관관계를 제시하였다. 아울러 풍력발전시스템의 연계변압기 중성점접지방식이 고장전류에 미치는 영향을 살펴본다. 계통에서의 1선 지락고장에 대해 연계변압기의 4가지 결선방식의 차이에 따른 고장전류, 전압 및 발전기의 특성 변화를 확인할 수 있었으며 중성점 접지방식의 차이에 따른 고장전류의 변화를 확인하였다. 사례연구를 통하여 제안한 Simulink에서의 시뮬레이션 모델의 효용성을 입증하였다.

• 전기학회논문지
• /
• 제60권5호
• /
• pp.955-964
• /
• 2011

In renewable energy system such as flywheel energy storage system, wind power and solar power, the motor/generator is the important key for offering the electric energy to the electric loads. For example, the heavy and large flywheel is rotated by electromagnetic torque of pemanent magnet synchronous motor (PMSM) and, in case of a breakdown of electric current, the PMSM used as generator supplies electric energy for the various electric utilities using mechanical rotation energy of the flywheel. Thus, design of a motor/generator should be performed in effort to reduce cogging torque and electromagnetic loss for high efficiency. In our paper, a slotless permanent magnet synchronous motor/generator (SPMSM/G) with output power 15kW at the rotor speed 18000rpm is designed from electromagnetic analysis and dynamic performance analysis. In analytical approach, design parameters such as back electro-motive force (back EMF), inductance and electromagnetic torque are derived from analytical method which is one of the electromagnetic analysis method. And using the design parameters, this paper deal with system design considering the driving characteristics and electric load in required power. Finally, the analytical results are verified by the experiment and finite element method (FEM).

• Journal of Electrical Engineering and Technology
• /
• 제12권1호
• /
• pp.145-150
• /
• 2017

This paper present a unified method of steady state performance analysis and limits characteristics of an autonomous three-phase self-excited induction generator (SEIG) driven by a wind turbine under different types of loads and speeds. The proposed method is based on a new mathematical function to solve for the real and imaginary components of the complex equation of the mathematical model. Performances limits, regulation and characteristics of different configurations will be thoroughly examined and compared. The proposed system will be modeled and simulated and the performance limits characteristics will be compared with variable speed and variable capacity.

• Transactions on Electrical and Electronic Materials
• /
• 제18권5호
• /
• pp.265-272
• /
• 2017

This paper presents the dynamic modeling, analysis, and control of an AC/DC/AC-assisted, self-excited induction generator connected to the grid. The dynamic model includes wind turbine models with pitch control, gear boxes, self-excited induction generators, excitation capacitance, inductive load models, controlled six-pulse rectifiers, and novel state-space models of a grid-connected inverter. The system has been simulated to verify its capabilities of buildup voltage, stator flux response, stator phase current, electromagnetic torque, and magnetizing inductance variation during both the dynamic and steady states with a variable-speed prime mover. The complete setup of the above dynamic models was simulated using MATLAB/SIMULINK.

• Journal of Advanced Marine Engineering and Technology
• /
• 제38권3호
• /
• pp.262-268
• /
• 2014

본 연구는 2MW급 풍력 발전기용 고속커플링의 요구조건인 유연성과 절연성 및 과부하시 기능부품의 파손을 방지하기 위한 동력 차단기능을 만족하기 위한 구조설계와 검증에 관한 것이다. 커플링의 유연성과 절연기능은 강도와 유연성 및 절연성을 동시에 가지는 유리섬유강화플라스틱을 이용하여 설계하였으며 유한요소해석을 통하여 원소재 두께를 최적화하였다. 또한 이상 토크 발생시 동력전달을 차단하기 위한 토크리미터를 마찰차 형식으로 설계하였다. 시제품의 성능평가를 통하여 설계변수의 타당성을 검증하였다.

• Journal of Electrical Engineering and Technology
• /
• 제10권2호
• /
• pp.688-698
• /
• 2015

This paper presents a modeling and a controller design for a hybrid wind turbine generator, especially with an operating mode of battery energy-storage system and a dumpload that contribute to the frequency control of the system while diesel-synchronous unit is not in operation. The proposed control scheme is based on a robust tracking controller, which takes an account of system uncertainties due to the wind flow and load variations. In order to provide robustness for system uncertainties, the range of operation is partitioned into three operating conditions as sub-models in the controller design. In the simulation study, the proposed robust tracking controller (RTC) is compared with the conventional proportional-integral (PI) controller. Simulation results show that the effectiveness of the RTC against disturbances caused by wind speed and load variation. Thus, better quality of the hybrid wind power system is achieved.

• 한국전산유체공학회지
• /
• 제18권1호
• /
• pp.36-42
• /
• 2013

The performance of the wind turbine is determined by wind speed and unsteady flow characteristics. Unsteady wake flow causes not only the decline in performance but also structural problems of the wind turbine. In this paper, conceptual designs for the wind turbine tower are conducted to minimize unsteady wake flow. Numerical simulations are performed to inspect the shape effect of the tower. Through the installation of additional structures at the rear of the tower, the creation of Karman vortex is delayed properly and vortex interactions are reduced extremely, which enhance the stability of the wind turbine. From the comparative analysis of lift and drag coefficients for each structure, it is concluded that two streamwise tips with a splitter plate have the most improved aerodynamic characteristics in stabilizing wake flow.