• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1435-1441
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• 2017

Distributed generation (DG) in the future will play an important role in the electricity supply systems, in wich can provide DG capacity from a few hundred kW to tens of MW. However, it is connected to the local power grid, DG will have certain influence on the power quality of the power grid. One of the most significant effects is that they will change the configuration of the local power grid as well as affecting the operation mode of the grid. This paper presents a method of finding the optimal open loop, analyzing and selecting the appropriate mode of operation to reduce power losses of power distribution networks that includes DG.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.1-5
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• 2008

Negative environmental consequences of fossil fuels and the concerns about their soaring prices have spurred the search for alternative energy sources. While other alternative energies-like solar, wind, geothermal, hydroelectric, and tidal-offer viable options for electricity generation, around 40% of total energy consumption requires liquid fuels like gasoline or diesel fuel. This is where bio-energy/biofuels is especially attractive, where they can serve as a practical alternative to oil. The production of liquid biofuels for transportation will depend upon a stable supply of large amount of inexpensive cellulosic biomass obtained on a sustainable basis. This paper reviewed development status of transportation bio-energy for vehicles, technical barriers to the production of cellulosic ethanol, and the global future of bio-diesel and ethanol production.

• Advances in Energy Research
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• v.4 no.2
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• pp.163-176
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• 2016

Rapid depletion of fossil based oil, coal and gas reserves and its greater demand day by day necessitates the search for other alternatives. Severe environmental impacts caused by the fossil fire based power plants and the escalating fuel costs are the major challenges faced by the electricity supply industry. Integration of Distributed Generators (DG) especially, wind and solar systems to the grid has been steadily increasing due to the concern of clean environment. This paper focuses on a new simple and fast load flow algorithm named Backward Forward Sweep Algorithm (BFSA) for finding the voltage profile and power losses with the integration of various sizes of DG at different locations. Genetic Algorithm (GA) based BFSA is adopted in finding the optimal location and sizing of DG to attain an improved voltage profile and considerable reduced power loss. Simulation results show that the proposed algorithm is more efficient in finding the optimal location and sizing of DG in 15-bus radial distribution system (RDS).The authenticity of the placement of optimized DG is assured with other DG placement techniques.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.22-24
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• 2000

As a competition is introduced in the electricity supply industry, a congestion problem arises in the transmission network. The congestion causes the transmission cost to increase. One way to decrease the congestion cost is to control the transmission flow through the installation of FACTS(Flexible AC Transmission system). This paper deals with the optimal site of the FACTS for reducing the congestion cost using a shadow price which is one of the economic signals for the systems. Test results show that the site of the FACTS(UPFC) is optimal to minimize the congestion cost by the proposed algorithm.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.798-800
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• 2005

In competitive electricity markets, the System Operator (SO) coordinates the overall maintenance schedules whenever the collective maintenance schedule reported to SO by Gencos & Transco in the pool does not satisfy the specified operating criteria, such as system reliability or supply adequacy. We propose a two-layer mathematical algorithm amenable to maintenance scheduling problem into master problem and sub-problem. The master problem coordinates the scheduling, and sub-problem, DC optimal power flew, checks the adequacy. The proposed algorithm was demonstrated with a case study.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.825-827
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• 2005

제2차 전력수급기본계획에 나타난 여러 수치들에 대하여 전력시장 시뮬레이션을 통하여 발전사업에 미치는 영향을 분석하였다. 과거 실적데이터를 이용하여 전력시장 분석용 전산모형에 대한 정밀 튜닝과 검증을 시행하고, 이를 이용하여 장기 전력시장 시뮬레이션을 수행하였다. 시뮬레이션 결과 높은 예비율로 인하여 급격한 시장가격의 하락이 나타나며, 이로 인하여 대부분의 발전사업자가 설비용량의 증가에도 불과하고 전기판매금액이 큰폭으로 하락하는 추세를 보여주고 있다. 이러한 경영환경은 특히 첨두설비 중심의 사업자에게 더 크게 영향을 미치게 될 것으로 예상되는데, 이로 인하여 신규 건설계획이 다소 보수적으로 변경될 가능성이 존재한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.20
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• pp.55-61
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• 1989

The main contribution this research is the development of methodology which is capable of solving problems associated with the capacity expansion and operating schedule of energy industries. The principal concern of such industries is the proper allocation of primary energy which are required for the production of sufficient supply of electricity and petroleum products for the Korea`s energy needs. Nonlinear programming models are developed for power generation expansion planning and for the oil refinery industry. In order to deal with uncertainties about future demands for final energy, chance-constrained programming is used to formulate appropriate constraints. The methodology of the model can be used to evaluate Korean energy and expansion planning in the energy industry, especially the electric power generation industry and the refinery industry.

• Physical Therapy Korea
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• v.2 no.1
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• pp.62-70
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• 1995

The use of electricity to evoke s skeletal muscle response is FES, which is a form of functional electrical stimulation. In the case of the damaged spinal cord, the technique can supply stimulation to the lower moter neurons and their muscle fiber, which have been disconnected from control of the higher nervous system. Recent advances in electronics, particularly miniaturization, have made possible the design of much improved systems of electrodes and stimulaters for FES. Clinical research has followed two main lines: the use of FES in the upper extremities for producing functional hand rehabilitation in quadriplegics and in the lower extremities for producing standing and gait in paraplegics.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.2
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• pp.53-58
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• 2006

This paper proposes a small low-cost power quality compensator to be installed at the electricity supply inlet of residential customer. The compensator is composed of a single-phase active power filter with a simple controller using analog electronics, which can correct the power factor and damp out the harmonics. The operation and performance of proposed compensator was verified through simulations with PSCAD/EMTDC and experimental works with hardware prototype. The proposed compensator can offer reduction of power loss and improvement of power quality to the residential customer.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.6
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• pp.259-264
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• 2006

This paper addresses the collusive bidding that functions as a potential obstacle to a fully competitive wholesale electricity market. Cooperative game is formulated and the equation of its Nash Equilibrium (NE) is derived on the basis of the supply function model. Gencos' willingness to selectively collude is expressed through a bargain theory. A Collusion Incentive Index(CII) for representing the willingness is defined through computing the Gencos' profits at NE. In order to keep the market non-cooperative, the market operator has to know the highest potentially collusive combination among the Gencos. Another index, which will be called the Collusion Monitoring Index(CMI), is suggested to detect the highest potential collusion and it is calculated using the marginal cost functions of the Gencos without any computation of NE. The effectiveness of CMI for detecting the highest potential collusion is verified through application on many test market cases.