• Tribology and Lubricants
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• 제27권4호
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• pp.204-208
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• 2011

Yaw brakes are used in wind turbines to control the orientation of blades to be perpendicular to the wind. These devices are very important machine elements because they are closely related to the overall efficiency of wind turbines. One unit of yaw brakes is composed of a friction pad and a caliper. In this study, a tangential force between the friction pad and the disk is calculated when the brake is acting in 750 kW wind turbine. Then, stress distribution and the deformation of the caliper are calculated using a finite element analysis. An experimental equipment is also developed to verify the exactness of calculated results. The analytical and experimental results are presented and discussed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.286-289
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• 2008

Mass of generator is one of the most important characteristic value especially direct drive type wind turbine. This paper introduce how to decease mass of generator rotor frame without declining generator performance. To obtain optimal design of rotor frame, sensitivity analysis using Taguchi method and RSM(response surface method) are have been performed.

• 전기학회논문지
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• 제59권1호
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• pp.16-18
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• 2010

This paper presents monitoring system based on IEC61400-25 for 750kW-class DFIG wind power generation system. It consists of wind turbine PLC, Local and Remote I/O Server, human machine interface, and Web-server. Proposed System has been demonstrated in Daegi-ri, Kangwon-do, which aims to test IEC61400-25 communication capability of monitoring system and evaluate the performance of 750kW-class WTS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1190-1192
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• 2004

풍력을 이용한 풍력발전기의 전력변환 시스템을 개발하기 위해서는 바람특성을 정확히 분석하고 이를 대치할 수 있는 모의시험 장치가 필수적이다. 모의시험 장치는 풍향, 풍속 등의 인자들을 입력받아 회전 블레이드의 토오크를 전동기가 대신해서 발전기에 공급하게 된다. 본 논문에서는 풍력발전 모의시험 장치를 이용해서 현재 개발 중인 750kW gearless형 풍력발전 시스템의 인버터 특성과 고효율의 전력변환 설계를 위해 시험용 지그에서 시험한 결과를 보이고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.227-228
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• 2008

This paper presents monitoring system based on IEC61400-25 for 750kW-class DFIG wind power generation system. It is consists of wind turbine PLC, Local and Remote I/O Server, human machine interface, and Web-server. Proposed System has been demonstrated in Daegi-ri, Kangwon-do, which aims to test IEC61400-25 communication capability of monitoring system and evaluate the performance of 750kW-class WTS.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.59-63
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• 2005

The 800-kW PM (permanent magnet) synchronous generator is developed as a wind power generator. The matching converter is designed to control the torque and power depending on the wind speed regime. The generator starts to generate the power at the speed of 9 rpm and the rated output is generated at the speed of 25 rpm. The rated output power of an inverter is 750 kW when the PM synchronous generator is delivering 800 kW to the inverter. The inverter is specially designed to perform the maximum power point tracking (MPPT) at the low wind speed regime that is typical wind environment in Korea. The inverter test was done with a 2 MW M-G system at KERI (Korea Electric Research Institute). The M-G set has a 2 MW motor driver and a 38:1 gear to match the speed between the motor and the PM generator. The torque simulating the wind is applied to the PM generator by a DC motor. The test results show the inverter efficiency of $94.3\%$ at the rated power generating condition. The measured values show that the MPPT algorithm is working well. Overall reliability will be verified through the long-term site test.

• 비파괴검사학회지
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• 제31권1호
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• pp.68-76
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• 2011

음향방출기법은 구조물에 존재하는 손상 및 손상 메커니즘을 규명하는 가장 유효한 비파괴검사 수단으로 널리 이용되고 있다. 최근 이러한 재료 및 구조의 내부 손상의 실시간 모니터링이 가능한 기법을 활용하여 풍력 블레이드와 같은 대형 구조물의 건전성을 실시간으로 감시 가능하도록 하는 연구가 각광 받고 있다. 이러한 실시간 건전성 모니터링을 위해서는 손상 징후를 조기에 발견 가능하여 손상으로 인한 큰 피해가 발생하지 않도록 하는 능력이 필수적으로 요구된다. 이 논문에서는 신호 맵핑 기법을 이용한 새로운 손상 검출 기법의 제안 및 750 kW 블레이드 부분 시편을 이용한 검증 시험을 다루었다. 검증 시험 결과 신호 맵핑 기법은 시간 도달차 기법과 비교하여 낮은 위치 오차율과 높은 위치 표정 결과를 나타내었다. 신호 맵핑 기법은 기존 기법과 비교하여 센서 부착 위치 선정에서도 유연함을 가지는 것을 확인하였다.

• 전기학회논문지P
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• 제63권4호
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• pp.254-259
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• 2014

In this paper, we describe construction of a wind stabilization demo-site and effects of output power control of wind turbines for suppression of ramp rate using ESS (Energy Storage System). It is difficult to control the output power of distributed generator such as wind turbine which of variation is very large. If the large capacity wind farm be interconnected into power system may cause blackout due to Power Quality. For these reasons, the international standards such as Grid-Code is limited to less than 10 [%/min] of renewable energy ramp rate. The case of Korea, government actively conducts propagating large-scale renewable energy for green growth policy, to interconnecting more renewable energy into power system is necessary for stabilization technology. For these reasons, the POSCO consortium has constructed a wind stabilization demo-site that is configured as 500 [kWh] battery energy storage systems can output up to 3 [C-Rate] and two wind turbines rated 750 [kW]. In POSCO consortium, which implements various methods stabilizing output power of wind turbine such as smoothing, section firming and ramp control, we derive the results of long-term demonstration that can be controlled to satisfy to the international standard about ramp rate [%/kW] of wind turbine output power.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.37-41
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• 2005

풍력을 이용한 풍력발전기의 전력변환 시스템을 개발하기 위해서는 바람의 특성을 정확히 분석하고 이를 대치할 수 있는 모의시험 장치인 시뮬레이터가 필수적이다. 모의시험 장치는 풍향 풍속등의 인자들을 입력받아 회전자 블레이드의 토오크를 전동기가 대신해서 발전기에 공급하게 된다 본 논문에서는 풍력발전 모의시험 장치를 이용하여 750-kW gearless형 풍력발전기의 축소모델인 20-kW 모델 발전기와 고효율의 전력변환 장치 설계 및 인버터 특성을 위한 시험용 지그에서의 시험한 결과를 보이고자 한다.

• International Journal of Aeronautical and Space Sciences
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• 제1권1호
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• pp.92-102
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• 2000

In this study, the 750kW medium scale composite blade for the horizontal axis wind turbine system was designed and manufactured, and it was tested and evaluated by the specific structural test rig. In the test, it was found that local bucklings at the trailing edge of the blade and excessive deflections at the blade tip were happened. In order to solve these problems, the design of blade structure was modified. After improving the design, the abrupt change of deflection at the blade tip was reduced by smooth variation of the spar thickness and the local buckling was removed by extending the web length. The modified design was analyzed by the FEM, the safety and stability of the blade structure. And Fatigue life over 20 years was confirmed by using S-N linear damage method, Spera's method, etc.