• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.792-800
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• 2007

The annual power cost for Seoul metro operations is about 65.5 billion won, of which rail motors account for 60% among total power consumptions. It is expected that the power consumption would increase because of global warming, future high electric equipments demands, etc. To reduce these consumptions, it is necessary to analyze the transportation demands of passengers, arrange the power-saving driving environments, respond flexible vehicles service, and improve how to drive vehicles. These method to reduce power consumption for rail motors can lead to improve the Seoul metro management. In this research, the improvement plan is derived by collecting and analyzing the data for total 33 power consumptions factors, screening top 10 factors by priority and impact, establishing each hypothesis to execute correlation and recursion analyses. As a result of 4 items research among top 10 affected factors, the power consumption for rail motors in 2006 is effectively reduced; the power usage is down with 13,870 kwh, from 531,539 kwh to 517,669 kwh, and the cost is down with 1,026 million won, from 39, 334 million won to 38,308 million won.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1169-1170
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• 2006

Grid connected PV(Photovoltic) generation systems are becoming and actual and general. The power output of PV system is directly affected by the weather conditions. And when AC power supply is needed, power conversion by an inverter and a MPPT control are necessary. The PV power generation system can be treated to a harmonics source for the power distribution system. So, the PV system combined the function of active filter system can be useful applied in power distribution system. AF(Active Filters) intended for harmonic solutions are expending their functions from harmonic compensation of nonlinear loads into harmonic isolation between utilities and consumer. With the test analysis of the proposed control strategy of PV-AF system, the outcome of the test shows the stability and effectiveness of the proposed PV-AF system. The various capability of AF has been proved in previous research and usage. In this paper, authors present a DSP controlled PV-AF system for power conditioning in three-phase industrial or commercial power systems and verify it through experimental results.

• 전기학회논문지
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• 제61권9호
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• pp.1260-1268
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• 2012

Recently, lack of power reserve margin was observed quite often. In this paper, we studied the method to secure power source for a short time, to cut the utility power peak load, and to reduce the users electricity bills. Emergency diesel generator of an office building is to be converted into a dual-fuel engine generator which is responsible for a portion of the peak load. Compared to the conventional diesel fuel generator, the proposed dual-fuel engine is able to reduce the generation power cost by dual-fuel combustion, and it also mitigates the building's utility power peak load by charging the building's peak load. If the dead resources (a group of emergency dual-fuel engine generators), as a Virtual Power Plant, are operating in peak time, we can significantly reduce future large power development costs. We investigated the current general purpose electricity bills as well as the records of the building electric power usage, and calculated diesel engine generator renovation costs, generation fuel costs, driving conditions, and savings in electricity bills. The proposed dual-fuel engine generation method reduces 18.1% of utility power peak load, and turned out to be highly attractive investment alternative which shows more than 27% of IRR, 76 million won of NPV, and 20~53 months of payback periods. The results of this study are expected to be useful to developing the policy & strategy of the energy department.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.365-368
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• 2006

The objective of this research is to investigate usage of 3KW photovoltaic-wind power hybrid generation system composed of 500W solar power generator and 400W wind power generator in a parallel circuit. In addition, solar radiation meter and wind monitor have been installed into each generation system to obtain the practical operating data that monitored in monthly, daily and hourly. These data that are independent to weather change and location would provide adequate generation output on average and cope with emergency situation in generation system In conclusion, based on this study, it could be considered for 3KW combined generation system to be gradually propagated to houses and small-size public facilities.

• 한국산업융합학회 논문집
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• 제14권3호
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• pp.95-100
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• 2011

The modern society longing for the convenience of up-to-date technology, there are attempts of miniaturization and high reliance of power equipments in the effectiveness aspect of urban area's usage of space while requiring more electrical energy than now. Consequently, paper used to the Neral Network for a forcasting conservation system. A neral network is powerful asta modeling tool that is able to capture and represent complex input/output relationships. The true power and advantage of neral networks lies in their ability to learn these relationships directly from the data being modeled. Traditional linear models are simply inadequate when it comes to modeling data that contains non-linear characteristics. Form results of this study, the Neral Network is will play an important role for insulation diagnosis system of real site GIS and power eqipment using $SF_6$ gas.

• 전기학회논문지P
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• 제58권2호
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• pp.231-234
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• 2009

Recently, to the development of a highly information-oriented society to a large increase in dependence on power, Accordingly, it is need that active development and spread of preservation technology on accident prevention in operation electrical equipment. However, to lack of the use on maintenance technology of power equipment and to increase of power usage is growing deterioration of power equipment, this is a cause on casualties, property damage and the occurrence of disasters is a growing. GIS equipments which are operated from domestic except the equipment which manages from the big business are depend on a most visual inspection, and do inspection method or measuring instrument etc. a condition which is not supplied widely. Currently, many to measure instrument used in domestic is very expensive or foreign, it will be able to substitute this, the development necessity of the diagnosis technique and the measuring instrument is demanded.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2348-2355
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• 2015

Transformer mineral oil which is normally hydrocarbon based is non- biodegradable and pollutes the environment in all aspects. Though vegetable oils are eco-friendly in nature and potentially could be used in transformers as a replacement for the mineral oil, there usage is restricted because of their oxidative instability. The present work focuses on using rapeseed oil and pongamia (pongamia pinnata) oil as effective alternatives for the traditional mineral oil in power transformer. The oxidative stability of the rapeseed oil and pongamia oil is increased by using combinations of the natural and synthetic anti-oxidants as additives. The parameters like breakdown voltage, viscosity, flash point, fire point are measured for the rapeseed oil and pongamia oil with and without the additives as per IEC and ASTM standards. The results shown encouraging changes in the parameter values and ensures the use of the oils as a potential alternative insulation in power transformers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.416-417
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• 2006

The recent movement to deregulated and competitive electricity market requires new concepts against existing central dispatch in the system operation and planning. As power systems tend to be operated more closely to their ultimate ratings, the role of SCOPF(Security Constrained Optimal Power Flow) is changed. This paper deals with the proper Unit Commitment condition changed according to the conditions or configuration of power system. This goal of is paper is to obtain proper security and Optimal UC condition through the efficient usage of the sensitivity Factor against critical contingencies. The proposed mechanism has been tested on a sample system and results show more secure conditions against critical contingencies.

• 대한임베디드공학회논문지
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• 제10권3호
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• pp.151-156
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• 2015

Recently, an embedded flash memory has been widely used for the Internet of Things(IoT). Due to its nonvolatility, economical feasibility, stability, low power usage, and fast speed. With respect to power consumption, the embedded memory system must consider the most significant design factor. The objective of this research is to design high performance and low power NAND flash memory architecture including a dual buffer as a replacement for NOR flash. Simulation shows that the proposed NAND flash system can achieve better performance than a conventional NOR flash memory. Furthermore, the average memory access time of the proposed system is better that of other buffer systems with three times more space. The use of a small buffer results in a significant reduction in power consumption.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.432-434
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• 2002

Recently, electricity demand of remote islands in Korea has been rapidly increased. It's mainly due to increase of income level resulted from economic development. Electricity demand patterns and characteristics in remote islands are different from those of mainland in point of time of peak load, demographic and industrial characteristics of islands, and so on. The optimal power supply in remote islands has a important relationship with accurate analysis of island's load characteristics, the adoption of relevant load forecasting technique, and optimal power facilities reflecting local's electricity demand characteristics. This paper shows the recent load pattern and characteristics, load forecasting using probability distribution, and the perpetration of relevant power facilities in remote islands.