• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.43.1-43.1
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• 2011

The detail simulation modeling of fully-fed induction generator is investigated through PC based MATLAB/Simulink environment. Generator's stator currents are controlled by indirect vector control method. In this method, generator side converter controls the maximum excitation (air gap flux) by stator d-axis current and controls generator torque by stator q-axis current. Induction generator speed is controlled by tip speed ratio (TSR) upon the wind speed variations in order to generate the maximum output power. The generator torque model is specified as a 3-blade wind turbine with rating, then, the model is simulated under normal operating condition and three different fault conditions. The matlab model designed for fully-fed induction generator based wind farm provides good performance under normal and grid fault conditions. It provides good results for different pwm techniques and fault conditions except the single-phase line to ground fault, which should be verified with real time data from wind farms.

• 한국연소학회지
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• 제19권4호
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• pp.14-20
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• 2014

In the present study, an annular combustor for a 500 W class micro gas turbine generator was designed and its characteristics were investigated by using both numerical and experimental methods. For this purpose, geometrical configurations of the annular combustor were determined in the aspect of the aerodynamic and chemical consideration. Also, fluid flow and pressure drop characteristics in the combustor were numerically studied by using commercial tool, FLUENT. Based on the numerical results, the diameter and the angle of air admission holes in the primary zone were chosen to be 2.5 mm and $30^{\circ}$, respectively. Finally, an integrated test unit, which consisted of a compressor, combustor, turbine, and motor/generator, was developed in order to measure the combustor efficiency. As the temperature difference between the combustor inlet and the turbine inlet or the air mass flow rate increased, the combustor efficiency increased and it was over 90% when the air mass flow rate was larger than 7.30 g/s. It was shown that the annular combustor developed in this study met the design requirement for a 500 W class micro gas turbine generator.

• Advances in Energy Research
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• 제7권1호
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• pp.67-84
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• 2020

Given the recent surge of interest towards utilization of renewable distributed energy resources (DER), in particular in remote areas, this paper aims at designing an optimal hybrid system in order to supply loads of a village located in Esfarayen, North Khorasan, Iran. This paper illustrates the optimal design procedure of a standalone hybrid system which consists of Wind Turbine Generator (WTG), Photo Voltaic (PV), Diesel-generator, and Battery denoting as the Energy Storage System (ESS). The WTGs and PVs are considered as the main producers since the site's ambient conditions are suitable for such producers. Moreover, batteries are employed to smooth out the variable outputs of these renewable resources. To this end, whenever the available power generation is higher than the demanded amount, the excess energy will be stored in ESS to be injected into the system in the time of insufficient power generation. Since the standalone system is assumed to have no connection to the upstream network, it must be able to supply the loads without any load curtailment. In this regard, a Diesel-Generator can also be integrated to achieve zero loss of load. The optimal hybrid system design problem is a discrete optimization problem that is solved, here, by means of a recently-introduced meta-heuristic optimization algorithm known as Lightning Attachment Procedure Optimization (LAPO). The results are compared to those of some other methods and discussed in detail. The results also show that the total cost of the designed stand-alone system in 25 years is around 92M€ which is much less than the grid-connected system with the total cost of 205M€. In summary, the obtained simulation results demonstrate the effectiveness of the utilized optimization algorithm in finding the best results, and the designed hybrid system in serving the remote loads.

• 전기학회논문지
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• 제65권6호
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• pp.923-933
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• 2016

This paper proposes a new method for evaluating Effective Load Carrying Capability(ELCC) and capacity credit(C.C.) of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). WTG can only generate electricity power when the fuel(wind) is available. Because of fluctuation of wind speed, WTG generates intermittent power. In view point of reliability of power system, intermittent power of WTG is similar with probabilistic characteristics based on power on-off due to mechanical availability of conventional generator. Therefore, high penetration of WTG will occur difficulties in power operation. The high penetration of numerous and large capacity WTG can make risk to power system adequacy, quality and stability. Therefore, the penetration of WTG is limited in the world. In recent, it is expected that BESS installed at wind farms may smooth the wind power fluctuation. This study develops a new method to assess how much is penetration of WTG able to extended when Wind Turbine Generator(WTG) is combined with Battery Energy Storage System(BESS). In this paper, the assessment equation of capacity credit of WTG combined with BESS is formulated newly. The simulation program, is called GNRL_ESS, is developed in this study. This paper demonstrates a various case studies of ELCC and capacity credit(C.C.) of power system containing WTG combined with BESS using model system as similar as Jeju island power system. The case studies demonstrate that not only reasonable BESS capacity for a WTG but also permissible penetration percent of WTG combined with BESS and reasonable WTG capacity for a BESS can be decided.

• 한국산학기술학회논문지
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• 제21권9호
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• pp.380-386
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• 2020

소방용 비상발전기는 화재와 같은 비상상황에서 인명과 재산을 보호하는 소방시설에 비상전원을 공급하는 중요한 시설이다. 이러한 중요성에 따라 비상발전기는 주기적인 부하시험으로 성능과 상태를 확인하여야 한다. 비상발전기의 일반적인 부하시험 방법은 R, L, C 부하로 구성된 Load Bank를 이용하여 시험하고 있다. 최근, 비상발전기의 효율적인 부하시험을 위하여, 시험 중에 발생한 전력을 저장하였다가 전기사업자에게 판매하는 ESS 부하시험장치의 도입이 검토되고 있다. 그러나 리튬이온배터리의 높은 가격으로 인하여, ESS 부하시험장치는 기존의 Load Bank 방식보다 초기투자비가 많이 소요될 수 있어, 상용화가 어려운 실정이다. 하지만, 비상발전기의 부하시험 동안 발전된 전력의 판매를 고려하면, ESS 부하시험장치는 경제적인 사업모델이 될 가능성이 있다. 따라서, 본 논문에서는 ESS 부하시험장치의 정확한 경제성을 평가하기 위하여, ESS 부하시험장치에 충전된 전력의 판매를 고려한 비용요소와 편익요소로 구성된 경제성평가 모델링을 제시한다. 또한, 제시한 모델링을 바탕으로 ESS 부하시험장치와 Load Bank에 대한 투자회수율과 회수년도를 비교 및 분석한 결과, 전력판매를 고려할 경우 ESS 부하시험장치의 상용화가 가능함을 확인하였다.

• 전기학회논문지
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• 제64권4호
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• pp.505-514
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• 2015

This paper proposes a probabilistic generation assessment model of renewable energy generators(REGs) considering uncertainty of resources, mainly focused on Wind Turbine Generator(WTG) and Solar Cell Generator(SCG) which are dispersed widely in South Korea The proposed numerical analysis method assesses the one day-ahead generation by combining equivalent generation characteristics function and probabilistic distribution function of wind speed(WS) and solar radiation(SR) resources. The equivalent generation functions(EGFs) of the wind and solar farms are established by grouping a lot of the farms appropriately centered on Weather Measurement Station(WMS). First, the EGFs are assessed by using regression analysis method based on typical least square method from the recorded actual generation data and historical resources(WS and SR). Second, the generation of the REGs is assessed by adding the one day-ahead resources forecast, announced by WMS, to the EGFs which are formulated as third order degree polynomials using the regression analysis. Third, a Renewable Energy Generation Assessment System(REGAS) including D/B of recorded actual generation data and historical resources is developed using the model and algorithm predicting one day-ahead power output of renewable energy generators.

• 한국해양환경ㆍ에너지학회지
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• 제17권2호
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• pp.146-152
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• 2014

선형발전기와 연성된 원통형 부이의 수직운동으로부터 파랑에너지를 추출하는 파력발전장치의 설계과정을 소개하였다. 최대 파워는 최적조건($c_{PTO}=b_T$, ${\omega}={\omega}_N$)에서 발생하며, 공진조건시 부이의 수직운동 고유주파수와 속도스펙트럼의 피크 주파수를 일치시키지 않고 의도적으로 고유주파수를 15% 크게 설정하면 추출파워의 최대값을 더욱 높일 수 있다. 이러한 방법을 통하여 추출 파워의 증가와 함께 부이의 흘수를 낮추고 동시에 PTO 감쇠력을 줄일 수 있기 때문에 발전장치 제작 비용을 낮출 수 있는 부수적인 효과를 얻을 수 있었다.

• 전기학회논문지
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• 제65권2호
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• pp.239-246
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• 2016

In recent years, the power demand has been increasing steadily and the occurrence of maximum power demand has been moving from the summer season to the winter season in Korea. And since the control of electric power supply and demand is more important under those situations, a micro-grid system began to emerge as a keyword for the sTable operation of electric power system. A micro-gird power system is composed of various kinds of distributed generators(DG) such as small diesel generator, wind turbine, photo-voltaic generator and energy storage system(ESS). This paper introduces a method to determine the optimal capacities of the distributed generators which are installed in a stand-alone type of microgrid power system based on the fundamental proportion of diesel generator. At first, the fundamental proportion of diesel generator will be determined by changing from 0 to 50 percent. And then we will optimize the capacities of renewable energy resources and ESS according to load patterns. Lastly, after recalculating the capacity of ESS with consideration for SOC constraints, the optimal capacities of distributed generators will be decided.

• 전기전자학회논문지
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• 제23권2호
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• pp.586-593
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• 2019

본 논문은 초미세먼지 증가를 억제하고자 1972년 건설된 국내무연탄과 유류를 혼소하는 발전설비를 2017년 국내최초, 최대 용량의 신재생 발전 연료 중 하나인 순수 목재를 가공한 친환경 고형연료인 바이오매스[우드팰릿] 발전방식으로 변경하였다. 발전기 제어계 중요 설비 교체에 따른 산업부 고시 "전력계통 신뢰도 및 전기품질 유지기준" 제 32조 발전설비 신/증설 시 발전설비 특성자료를 제출에 의거 발전기 기술특성시험을 실시하였으며, 시험을 통하여 발전기/제어계 모델정수 도출 및 검증을 수행하였다. 발전기 연료변경에도 해당 발전기 설비의 성능 및 여자시스템의 전압제어특성이 양호함을 재확인하였다. 차후 화석연료를 신재생 연료로 교체하고자 하는 발전소에서 참고하는데 기여할 수 있다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 추계 학술발표회 논문집
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• pp.248-255
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• 1998