• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.495-497
• /
• 2001

Ullung wind power plant is a remarkable event to get a great concern of many people, because it has been observed as a first case of combining the new large different generating sources, i. e. hybrid diesel-wind power system. This paper is dealing with the analysis of this problem and with the grid-coordination. The first endeavor of actual measurement was performed at site during October 18-21. 2000 and a part of this records is presented in this paper.

• Wind and Structures
• /
• 제18권4호
• /
• pp.375-389
• /
• 2014

The high-frequency force-balance (HFFB) technique and its subsequent improvements are reviewed in this paper, including a discussion about nonlinear mode shape corrections, multi-force balance measurements, and using HFFB model to identify aeroelastic parameters. To apply the HFFB technique in engineering practice, various validation studies have been conducted. This paper presents the results from an analytical validation study for a simple building with nonlinear mode shapes, three experimental validation studies for more complicated buildings, and a field measurement comparison for a super-tall building in Hong Kong. The results of these validations confirm that the improved HFFB technique is generally adequate for engineering applications. Some technical limitations of HFFB are also discussed in this paper, especially for higher-order mode response that could be considerable for super tall buildings.

• 기술사
• /
• 제44권2호
• /
• pp.39-42
• /
• 2011

The main concern at the moment is securing rare earth(RE) resources, because the RE is the essential elements in green technology such as hybrid car, wind power plant, LED, display etc. It's impossible Korea will be a advanced country without securing RE. The importance of investment radically in the securing RE resources and professional engineers can not be overinvested.

• 드라이브 ㆍ 컨트롤
• /
• 제8권1호
• /
• pp.44-49
• /
• 2011

• 전기학회논문지P
• /
• 제67권3호
• /
• pp.143-148
• /
• 2018

In this paper, the optimal fuzzy logic controller(FLC) for a hybrid renewable energy system(HRES) is proposed. Generally, hybrid renewable energy systems can consist of wind power, solar power, fuel cells and storage devices. The proposed FLC can effectively control the entire HRES by determining the output power of the fuel cell or the absorption power of the electrolyzer. In general, fuzzy logic controllers can be optimized by classical optimization algorithms such as genetic algorithms(GA) or particle swarm optimization(PSO). However, these FLC have a disadvantage in that their performance varies greatly depending on the control parameters of the optimization algorithms. Therefore, we propose a method to optimize the fuzzy logic controller using the teaching-learning based optimization(TLBO) algorithm which does not have the control parameters of the algorithm. The TLBO algorithm is an optimization algorithm that mimics the knowledge transfer mechanism in a class. To verify the performance of the proposed algorithm, we modeled the hybrid system using Matlab Tool and compare and analyze the performance with other classical optimization algorithms. The simulation results show that the proposed method shows better performance than the other methods.

• 한국수소및신에너지학회논문집
• /
• 제29권6호
• /
• pp.606-619
• /
• 2018

This study focuses on the performance of hydrogen energy based hybrid system in terms of system reliability of electricity generation. With this aim to evaluate the off-grid system of photovoltaic (PV), wind turbine, electrolyzer, fuelcell, $H_2$ tank and storage batteries, 14 different sites in South Korea are simulated using HOMER. Performance analysis includes simulation on the different sites, verification of operational behaviors on regional and seasonal basis, and comparison among a control group. The result shows that the generation performance of hydrogen powered fuelcell is greatly affected by geographical change rather than seasonal effect. In addition, as the latitude of the hybrid systems location decrease, renewable power output and penetration ratio (%) increase under constant electrical load. Therefore, the hydrogen based hybrid system creates the stability of electricity generation, which best suits in the southern part of South Korea.

• 한국소음진동공학회논문집
• /
• 제23권9호
• /
• pp.814-822
• /
• 2013

For the fault diagnosis of a mechanical system, pattern recognition methods have being used frequently in recent research. Hidden Markov model(HMM) and artificial neural network(ANN) are typical examples of pattern recognition methods employed for the fault diagnosis of a mechanical system. In this paper, a hybrid method that combines HMM and ANN for the fault diagnosis of a mechanical system is introduced. A rotating blade which is used for a wind turbine is employed for the fault diagnosis. Using the HMM/ANN hybrid model along with the numerical model of the rotating blade, the location and depth of a crack as well as its presence are identified. Also the effect of signal to noise ratio, crack location and crack size on the success rate of the identification is investigated.

• 한국유체기계학회 논문집
• /
• 제15권2호
• /
• pp.5-11
• /
• 2012

In this paper, the heat transfer coefficient measurement techniques using TSP(temperature sensitive paint) were introduced and the results of a comparative study on the heat transfer coefficient measurement by steady state and transient TSP techniques were discussed. The distributions of heat transfer coefficient by a single $60^{\circ}$ inclined impingement jet on a flat surface were measured by both techniques. Tested Reynolds number based on the jet diameter (d) was 30,000 and the distance between jet exit and target plate (L) was fixed at 10d. Results showed that the measured Nusselt number by both techniques indicated significant difference except near the center of impingement jet. Also, the heat transfer coefficients measured by the transient TSP technique were affected by the reference temperature of the jet. Based on the measured data, characteristics of both TSP techniques were analyzed and suggestions for applying them were also given.

• 조명전기설비학회논문지
• /
• 제26권9호
• /
• pp.64-72
• /
• 2012

The interest in wind power generation area such as developing and operating wind-diesel pilot complex in remote and island regions that have difficulty in having power plant and connecting to power system is growing rapidly in the world. We have installed and researched the hybrid system in Sekgok Pilot Complex to meet the new generation system. From the monitored data of the system, the performance of each diesel power plant is outstanding. However, step out problem was detected with respect to load sharing and synchronization with decentralized power supply. An advanced controller design having better response time and stability is needed to solve such problem. In this paper, we proposed the algorithm, through digital controller of Governor, which is applied to hybrid system. As a result, we obtained the stable frequency value in variable loading conditions. Also, we proved the advanced response time and stability through the simulation and experiment by applying additional current signal to the control algorithm.

• 한국지능시스템학회논문지
• /
• 제16권6호
• /
• pp.753-758
• /
• 2006

본 논문에서는 하이브리드 발전 시스템에서의 최대 전력 추종을 위한 디지털 퍼지 제어기 설계를 목표로 한다. 하이브리드 발전 시스템은 풍력과 태양광, 두 개의 발전 시스템으로 구성된다. 각 발전기에서 전압과 전류는 일반적으로 비선형 관계에 있기 때문에, 퍼지 모델 기반 제어기를 사용하여 비선형성을 효율적으로 제어하게 된다. 또한 마이크로프로세서 기반제어 시스템의 구축을 위하여 최신 디지털 재설계 기법을 사용하며, 디지털 퍼지 제어기를 설계하게 된다. 마지막으로 하이브리드 발전 시스템의 플랜트를 통한 실험으로써 본 제안 기법의 우수성을 입증한다.