• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.238-243
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• 2013

In this paper, a novel approach for optimized installation and operations of battery energy storage system (BESS) and electric double layer capacitor (EDLC) modules for the renewable energy based intermittent generation is presented for them to be connected with an electric power grid. In order to make use of not merely the high energy density of battery but also the high power density of EDLC modules, it is very useful to devise the hybrid system which combines BESS and EDLC modules. The proposed method adopts the linear programming to calculate the optimized capacity as well as the quadratic programming to transmit the optimal operational signals to BESS and EDLC modules. The efficiency of this methodology will be demonstrated in the experimental study with the real data of wind speed in Texas.

• 신재생에너지
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• 제1권3호
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• pp.14-23
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• 2005

Korean government set the goal of 5.6% to use renewable energy in electricity generation by 2011 compared with the current use of 0.13%. To achieve this goal, an innovative plan for market competitiveness would be required in addition to the feed-in-tariff [FIT] which is carried out at present in Korea. As a countermeasure, Ministry of Commerce, Industry and Energy [MOCIE] has taken it into consideration to introduce a Renewable Portfolio Standard [RPS] that is a purchase obligation program as an alternative plan to the FIT. Furthermore, the active renewable energy market may result from and also reversely result in the aid of North Korea with renewable energy. In this paper, we review The RPS in several country cases. Plans, systems, markets and institutionalization for solving efficiency in the area of renewable energy are discussed.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권2호
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• pp.70-78
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• 2012

Due to the variable nature of renewable energy resources and power demand by consumers, it is difficult to operate a power system installed with only one type of renewable energy resource. Grid-based renewable generation may be the only solution to overcome this problem. The conventional approach based on a low-voltage converter with power frequency transformer is commonly employed for grid connection of offshore renewable energy systems. Because of the heavy weight and large size of the transformer, the system can be expensive and complex in terms of installation and maintenance. In this paper, an 11-kV series connected H-bridge (SCHB) multilevel voltage source converter (VSC) is proposed to achieve a compact and light direct grid connection of renewable energy systems. This paper presents the design, simulation and analysis of a five level (5L)-SCHB and an eleven level (11L)-SCHB VSC for 11-kV grid-based renewable energy systems. The performance, cost, modulation scheme and harmonic spectra of the converter are analyzed.

• 한국정보시스템학회지:정보시스템연구
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• 제27권2호
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• pp.95-114
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• 2018

Purpose The recent concern over environmental problems such as greenhouse gas emission and fine dust contributes increasing interest in renewable energies. However the intrinsic characteristics of renewable energies, intermittent and stochastic generation, might cause serious problems to the stability and controllability of power grid. Therefore countermeasures such as virtual power plant (VPP) must be prepared in advance of the spread of uncontrollable distributed renewable energy resources to be one of major energy sources. Design/methodology/approach This study deals with the design concept of the VPP platform. we proposed as a technology solution for achieving the stability of power grid by guaranteeing a single power profile combining multiple distributed power sources with ICT. The core characteristics of VPP should be able to participate in the grid operation by responding to operation instructions from the system operator, KPX, as well as the wholesale electricity market. Findings Therefore this study includes energy storage device(ESS) as a controllable component as well as renewable energy resources such as photovoltaic and wind power generation. Based on this configuration, we discussed core element technologies of VPP and protype design of VPP solution platform according to system requirements. In the proposed solution platform, UX design for the integrated control center and brokerage system were included as well as ancillary service function to respond to KPX's operation instruction with utilizing the capability of ESS. In addition, a simulator was suggested to verify the VPP operations.

• 신재생에너지
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• 제7권1호
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• pp.8-14
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• 2011

As is the case in Korea, the expansion of renewable energy dissemination is an essential matter in Ukraine when considering its energy consumption and dependence on energy import. While Korea has set about promoting the new and renewable energy industry on the back of the national policy on green growth, Ukraine expects a virtuous circle of renewable energy industry with green tariffs and the attraction of foreign capital in association with carbon emission trade. Utilizing its well-developed heavy industrial sector including the shipbuilding and automobile industries, Korea expects wind turbine manufacturing to become one of its next-generation growth engines. Ukraine is also trying to enter the wind turbine system or parts manufacturing industry based on its automobile industry and advanced aerospace technology. Although the Crimean region in Ukraine seems to have excellent wind resources, and thus shows great potential as a location for wind farm development, political instability has been a major obstacle to the attraction of foreign capital, leading to delayed investment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.172-174
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• 1999

In Korea, the consumption of renewable energy among primary energies has marked only 1.03%, composed of mostly hydro power facilities, as of 1998. This situation has been basically due to the market limit and high generation cost of renewable energies. Furthermore, the policies and strategies for promoting the renewable energy have been insufficient in comparison with that of the developed countries. This paper mainly focuses on the economic feasibility and sensitivity analysis for renewable energies.

• 전기학회논문지
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• 제59권2호
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• pp.272-276
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• 2010

Renewable energy sources are considered to be environment-friendly alternatives those are increasingly introduced in the power systems. Microgrid is one of the systems in which renewable sources have a main role as a energy suppliers. Decision of constitution rates of renewable energy sources is very important for the economical and stable operation of microgird systems. In this paper, we present a method to assess an optimal constitution rate of renewable sources especially of windturbine and photovoltaic systems.

• 신재생에너지
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• 제2권1호
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• pp.66-71
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• 2006

CDM(Clean Development Mechanism) is one of three Kyoto mechanisms. As a non-annex I party of UNFCCC, Korea can host CDM projects. Currently eight CDM projects are hosted in Korea under Kyoto protocol. Six of these CDM projects are related to renewable energy power generation. Renewable energy power plants assumes zero GHGs emission and has great potential to become COM projects which is very environmental friendly energy. Gangwon wind park CDM project is the first renewable CDM project in Korea. In this research, emission factors and additionality proving process are studied, which are important procedures of doing CDM project.

• 전기학회논문지
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• 제59권9호
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• pp.1560-1565
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• 2010

The renewable resource are getting more attentions with increased concerns on the depletion of fossil fuels and several environmental issues like emission problem. Wind power is a representative option among several renewable sources and the generation capacity using wind power is being increased. However, the wind generation is so volatile on its output characteristic, so it is required to assess the grid impact of wind power generation by measuring the fluctuation effect more precisely. This paper proposes the method for measuring the generation output according to IEC 61400-21(Measurement and assessment of power quality characteristics of grid connected wind turbines) to assess the power quality of wind turbine generation. In addition, it shows an application case to a small-scale wind power generator. In the case study, it suggests a structure design of the proposed measurement instrument both on hardware and software aspects, which is composed of a remote monitoring & data analysis program and an FPGA based real-time signal processing device.

• 신재생에너지
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• 제2권4호
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• pp.86-92
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• 2006

This paper analyses the economics of 50kW PV system installed in Tibet and using domestic technology. We show that this system can be expanded to very large-scale photovoltaic power generation [VLS-PV] system successfully. Based on this result, we conduct the economic analysis of 100MW VLS-PV system designed assuming that it will be installed from 2008 to 2017 in Tibet. In this analysis, future price of PV module and system are estimated based on the methodology of experience curve. In 50kW PV system, the generation cost is calculated at 567.2 won/kWh and this is lower than the one of domestic PV system. In future 100MW VLS-PV system. the generation cost is calculated at 305.4 won/kWh by declining system price. If the lifetime and efficiency of the system goes up, due to future technological improvements, the generation cost can be lowered. Moreover, under the environmental and political effect, VLS-PV system can be as competitive as the conventional energy within 20 years.