• Journal of Mechanical Science and Technology
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• 제16권10호
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• pp.1287-1295
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• 2002

In this work, the fuel economy of a parallel hybrid electric vehicle is investigated. A vehicle control algorithm which yields operating points where operational cost of HEV is minimal is suggested. The operational cost of HEV is decided considering both the cost of fossil fuel consumed by an engine and the cost of electricity consumed by an electric motor. A procedure for obtaining the operating points of minimal fuel consumption is introduced. Simulations are carried out for 3 variations of HEV and the results are compared to the fuel economy of a conventional vehicle in order to investigate the effect of hybridization. Simulation results show that HEV with the vehicle control algorithm suggested in this work has a fuel economy 45% better than the conventional vehicle if braking energy is recuperated fully by regeneration and idling of the engine is eliminated. The vehicle modification is also investigated to obtain the target fuel economy set in PNGV program.

• 대한전기학회논문지:전력기술부문A
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• 제52권4호
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• pp.213-218
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• 2003

In front of the opening of electric distribution market in 2004, it is indispensable to have a proper estimation of power quality index and rower quality cost calculation mechanism which are indispensable to stabilize highly industrialized society and to vitalize the Investment lot electric power system. However, there were not enough measures to reflect the voltage characteristics such as voltage sags and Interruptions which make electric load in unstable operation. This paper suggests power quality index and power quality cost which translate various kinds of voltage records into bus load drop index(BLDI) and bus power quality cost(BPQC) based on aggregated load CBEMA curve. A sample calculation result shows that this method can produces the acceptable power Quality index and costs for utilities and customers requirements.

• 전기저널
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• 6호통권54호
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• pp.2-4
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• 1981

• 전기저널
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• 8호통권56호
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• pp.2-5
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• 1981

• 전기저널
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• 7호통권55호
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• pp.3-6
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• 1981

• 전기학회논문지
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• 제67권2호
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• pp.331-336
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• 2018

In this paper, the life cycle cost of the auxiliary power unit in the conventional 8200 series electric locomotive is evaluated and an effective life cycle cost reduction method is sought. For this, a life cycle cost evaluation model was proposed using IEC 60300-3-3 standard. As a result of analysis, material cost which accounted for a large percentage of preventive maintenance cost, accounted for 64% of total cost, and breakdown maintenance cost was as high as 27%. Except for the cost of preventive maintenance, the breakdown maintenance cost ratio was the highest. In order to reduce the LCC of the auxiliary power unit(APU) of the 8200 series in the future, it is necessary to reduce the material cost in case of development and to secure the high reliability according to the parts manufacturing so as to minimize the maintenance cost.

• 대한전기학회논문지:전력기술부문A
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• 제52권7호
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• pp.381-386
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• 2003

To provide a specified power quality under electric market system is becoming an important issue for customers and utility company. However, there is no realistic infra-structure to design a power system for the specified power quality. Present electric market is operating under the economic point of view. The low power price could be attractive, but the effect of low price could result the lower power quality for the long time and threat power system security. This paper presents a model which conceptualize the dynamic power quality control mechanism to minimize total cost of a society which is affected electric power quality. This model aims to produce a basic infra-structure to balance cost and quality under the electric market system.

• KEPCO Journal on Electric Power and Energy
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• 제3권2호
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• pp.119-125
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• 2017

Regarding the implementation of ROMM project (Rehabilitation, Operation, Maintenance & Management), which is one of overseas development projects, it is very important to diagnose the exact current status of aged thermal power plant. However, when people visit the power plant for the purpose of prediagnosis to implement the ROMM project, most target power plants for diagnosis, in general, are under operation. This can be a big interference factor to diagnose the exact current status of power plants. Therefore, in order to solve such interference factor, based on the 30 years of know-how in the field, the present study has developed a regression curve for a simple life time assessment and the calculation of rehabilitation cost that may be used as a reference relatively for the quantitative diagnosis on the status of a relevant power plant even during the operation of the power plant.

• 태양에너지
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• 제19권3호
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• pp.63-73
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• 1999

Ice storage systems are used to shift the peak load in day time into night time in summer. This paper describes a system simulation of partial ice storage system composed of an encapsulated ice storage tank, a screw compressor chiller, a heat exchanger, and a brine pump. For the system simulation, a one-dimensional model of ice storage tank is developed and validated by comparison with the performance data from measurements of an ice storage tank installed at a building. The control strategies considered in this study are chiller priority and storage priority being used commercially. The system is simulated with design cooling load of 600 RT peak load in design day and with off-design day cooling load, and the electric energy costs of the two control strategies for the same system size are compared. As a result of calculation, the energy consumption in a week for storage priority is higher than that for chiller priority control. However due to lower cost of night electric charge rate, energy cost for storage priority control is lower than chiller priority.

• 전기학회논문지
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• 제64권2호
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• pp.208-213
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• 2015

This study presents the estimation method for the optimal capacity of BESS(Battery Energy Storage System) in order to reduce the electric charges of common consumer. The daily optimal charge and discharge plan of BESS which satisfies the given constraints is established using linear programming through the change of rated output/rated capacity of the time that shows the electric charges in the highest reduced rate has been selected. There will be a problem to compare only reduced rate because the bigger the rated capacity, the more reduced rate is increased. Therefore, rated output/rated capacity of the time when the reduced amount of electric charges for a year is higher than the investment cost of BESS was selected.