• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1123-1130
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• 2018

Voltage stabilization is an essential component of power quality in low voltage DC (LVDC) microgrid. The microgrid demands the interconnection of a number of small distributed power resources, including variable renewable generators. Therefore, the voltage can be maintained in a stable manner through the control of these distributed generators. In this study, we did research on the new advanced operating method for a photovoltaic (PV) simulator in order to achieve interconnection to a bipolar LVDC microgrid. The validity of this voltage stabilization method, using the distributed generators, is experimentally verified. The test LVDC microgrid is configured by connecting the developed PV simulator and DC load, DC line, and AC/DC rectifier for connecting the main AC grid. The new advanced control method is applied to the developed PV simulator for the bipolar LVDC grid in order to stabilize the gird voltage. Using simulation results, the stabilization of the grid voltage by PV simulator using the proposed control method is confirmed the through the simulation results in various operation scenarios.

• 전기전자학회논문지
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• 제13권2호
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• pp.186-193
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• 2009

산업화가 가속되고 정보 가전기기의 사용이 급증함에 따라 열악한 국내 에너지 현실에서 신 재생 에너지의 개발과 보급은 절실히 요구되고 있다. 따라서 본 논문에서는 신 재생에너지의 적극적인 보급과 활용을 위하여, 분산 배치된 신 재생에너지 발전설비의 발전 데이터를 효율적으로 관리할 수 있는 통합 관리 운영시스템을 제안하였다. 또한 컴퓨터 바이러스. 스파이웨어와 다른 네트워크 문제로 인해 수집된 데이터의 유실을 방지하기 위해 통합 보완 관리 시스템을 적용하여 발전 데이터를 보호하도록 구성하였다.

• 조명전기설비학회논문지
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• 제27권11호
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• pp.57-68
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• 2013

The market for distributed power generation based on renewable energy is increasing, particularly for standalone mini-grid applications in developing countries with limited energy resources. Stand-alone power systems (SAPS) are of special interest combined with renewable energy design in areas not connected to the electric grid. Traditionally, such systems have been powered by diesel engine generator sets (DEGS), but also hybrid systems with photovoltaic and/or wind energy conversion systems (WECS) are becoming quite common nowadays. Hybrid energy systems can now be used to generate energy consumed in remote areas and stand-alone microgrids. This paper describes the design, simulation and feasibility study of a hybrid energy system for a stand-alone power system. A simulated model is developed to investigate the design and performance of stand-alone hydrogen renewable energy systems. The analysis presented here is based on transient system simulation program (TRNSYS) with realistic ventilation load of a large store. Design of a hybrid energy system is site specific and depends on the resources available and the load demand.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.1-5
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• 2014

When renewable sources are connected to the distribution network in the form of a distributed generators(DGs), the effect of intermittent output appears as voltage fluctuation. The surplus power at the consumer ends results in the reverse power flow to the distribution network. This reverse power flow causes several problems to the distribution network such as overvoltage. Application of the reactive power control equipment and power flow control by means of BTB inverter have been suggested as the general solutions to overcome the overvoltage, but they are not economically feasible since they require high cost devices. Herein, we suggest the feeder loop line switch control method to solve the problem.

• 에너지공학
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• 제18권2호
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• pp.132-135
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• 2009

바이오 디젤과 바이오 에탄올과 같은 바이오 연료의 상용화가 최근 주목할 만하며, 특히 2000년 이후에 그 생산량이 급격히 증가하였다. 세계적으로는 바이오 디젤의 생산량이 83억 리터에 이르고 있다. 유럽이 전체생산량의 80%를 생산하고 있으며, 오늘날 많은 국가에서 바이오 디젤을 상용화하고 있고, 세금감면과 재정적인 인센티브로 세계시장규모가 괄목할 만한 성장을 거두었다. 국내의 경우 이미 수송용 연료로 사용되고 있는 반면에 아직 발전용 연료로는 사용되지 않고 있다. 특히 정부에서는 신재생에너지 확대보급 정책에 따라 2012년까지 전체 발전량의 3%를 신재생에너지로 확보할 계획이다. 따라서, 본 논문에서는 바이오 디젤의 발전용 연료화를 통한 기대효과를 분석하였으며, 현재 운영중인 유류발전소 등에 적용시 기대효과에 대하여 평가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1442-1442
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• 2011

Increase the cost of electricity generation compared to (30 million won / KW) can only be used in standalone or distributed, but in the same area of photovoltaic conversion efficiency is much higher than with a large Stirling engine development has economic value of the infinite. Commercialization 25KW level or above Stirling engine production or introduction is necessary solar power in the various application and effect analysis for further empirical studies or regional energy projects, demonstration of business expansion and conductor, Stirling engines.

• 전력전자학회지
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• 제15권2호
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• pp.25-29
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• 2010

마이크로그리드(MIcro Grid)는 현재의 집중적인 전력공급 시스템의 대안으로 부각되고 있는 지역적 에너지공급체계로서 신재생에너지 (Renewable Energy)와 분산전원 (Distributed Generation) 및 정보통신기술의 발전에 따라 전력공급에서의 에너지손실 최소화, 분산자원의 효율적이고 효과적인 이용, 전력품질의 제고, 분산자원의 전력망 수용성 제고 등 다양한 목적으로 실증적인 연구가 진행되고 있는 기술이다. 본고에서는 마이크로그리드의 핵심기술인 운영기술을 그 목적별로 자세히 소개하고 국내에서의 마이크로그리드에 관련된 연구 동향을 살펴보고자 한다.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.433-440
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• 2014

In this study, a method for the low-carbon active distribution system (ADS) planning is proposed. It takes into account the impacts of both network capacity and demand correlation to the renewable energy accommodation, and incorporates demand response (DR) as an available resource in the ADS planning. The problem is formulated as a mixed integer nonlinear programming model, whereby the optimal allocation of renewable energy sources and the design of DR contract (i.e. payment incentives and default penalties) are determined simultaneously, in order to achieve the minimization of total cost and $CO_2$ emissions subjected to the system constraints. The uncertainties that involved are also considered by using the scenario synthesis method with the improved Taguchi's orthogonal array testing for reducing information redundancy. A novel cuckoo search (CS) is applied for the planning optimization. The case study results confirm the effectiveness and superiority of the proposed method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3359-3364
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• 2007

The smart energy system is the integrated power system in which the power components including central station generation, distributed generation, renewable power generation, energy storage, and communications and controls are complexly connected with each other. In smart energy system, it is very important how to configure the diverse power generations and how to determine the operation mode of the chosen components with economic feasibility. In this study, we introduce the optimal planning method based on both economic feasibility and load profiles and its applications for the smart energy system in apartment. This method was considered very useful to determine the configuration and to decide the optimal operation mode of the smart energy system.

• 한국산업융합학회 논문집
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• 제25권1호
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• pp.71-78
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• 2022

With the advent of cutting-edge technology, renewable energy is significantly considered as alternative resources to supply electric power. However, many barriers such as energy intermittency, high initial installation cost, and low-efficiency generation challenged building new infrastructure with clean energy. Efforts reducing greenhouse gas emissions and reliance on fossil fuels resulted in the decentralization of power generation like distributed energy resource (DER). This paper is to introduce and evaluate the feasibility of building-integrated photovoltaics (BIPV) in a high-rise building in Ulsan. To optimize BIPV, a variety of methods to minimize efficiency decrease and maximize electric power generation after installing BIPV on the building's facade are suggested. The variables causing power losses are analyzed. By utilizing System Advisor Model (SAM), actual power generated from solar panels is measured by Thin-film PV, Mono-crystalline PV, and Poly-crystalline PV.