• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2245-2253
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• 2018

With the increase of electrical consumption and the unbalance of power demand and supply, power reserve rate is getting smaller and also the reliability of the power supply is getting deteriorated. Under this circumstance, the electrical energy storage (EES) System is considered as one of essential countermeasure for demand side management. This paper proposes efficient evaluation algorithms of multiple functions for EES systems, especially the secondary battery energy storage systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a quantitative manner, because they are very costly right now. In this paper, the multiple functions of EES systems such as load levelling, effective utilization of power distribution systems and uninterruptible power supply are classified, and then the quantitative evaluation methods for their functions are proposed. From the case studies, it is verified that EES systems installed at distribution systems in a dispersed manner have multiple functions involved with direct and indirect benefits and also they can be expected to introduce to distribution systems with respects to economical point of view.

• 수산경영론집
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• 제31권1호
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• pp.115-133
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• 2000

The policy of suppling tax-exempt fishery oil in Korea has a history of almost 40 years, which was initiated by the National Federation of Fisheries Cooperatives in 1965. In 1999 the volume of fishery oil supplied to the earning fishermen and fishing entrepreneurs amounted to 8,390 thousand DM, 500 billion won in total. This paper analyzes the oil supplying system to fishermen in Korea and shows that the structural obstacles to the stable provision of fishery oil lies in the ineffective bargaining power (fixing price). Provided that the NFFC as a buyer, which is not equipped with the storage facilities for oil bids for a unit-price contract of fishery oil, there exists a possibility of collusion among 5 local oil refineries corporations to influence the oil price, making it difficult to reach a resonable price of oil. Though the international bids and direct imports following the liberalization of oil imports would help lower the unit price, purchasing and importing the oil out of season at a lower price would not be guaranteed without the oil storage facilities. Furthermore, the current supply system of oil is quite vulnerable to the extraneous factors and, say when the oil price soars unpredictably, it is almost impossible to supply low - priced fishery oil to fishermen. The National Federation of Fisheries Association of Japan(Zengyoren), for instance, possesses 10 oil storage facilities, which had been built across the country during the last 20 years (1964-1984). The storage capacity of these facilities reaches 0.6million DM(by kind, 0.56million DM for A heavy oil, 38thousand D/M kerosene, 5thousand D/M for diesel fuel oil). Allowing no intermediary of production associations(fisheries cooperatives) the NFFA's capacity for keeping oil in reserve rises much higher. As these storage facilities can keep the oil amounting to as much as of 70 days demand in reserve, a stable supply of fishery oil on favorable terms is secured. In contrast with Japan case, unequipped with the storage facilities for fishery oil, Korea does not have much bargaining power for bringing down the price of fishery oil. To make matters worse, the oil storing capacity of the member cooperatives is the volume of only 8 days demand. In case the oil price rises, it is almost impossible to supply the oil to the fishermen at a price lower than the price risen.

• East Asian Economic Review
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• 제16권1호
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• pp.3-23
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• 2012

The recent global financial crisis has highlighted the importance of international monetary and financial system reform. The current system is deemed to be no longer adequate to meet the needs of a complex, integrated world economy. With regards to the reform of the international monetary system, there have been various proposals both in demand and supply sides. These include proposals to build a stronger global financial safety net, to diversify the supply of international reserve currency and so on. These proposals face trade-offs between desirability and political feasibility. Given this situation, a practical transition would be to strengthen policy coordination among the major economies and to reform the International Monetary Fund. The success on both fronts depends heavily on global economic governance reform and the role of the G20. Increased status and representation of Asian countries in the G20 give both privileges and responsibilities to Asians. To meet these responsibilities, Asians should put forth greater efforts to develop their intellectual leadership in global economic issues through creating new forum and institutions.

• Journal of Electrical Engineering and Technology
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• 제2권1호
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• pp.1-9
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• 2007

This paper presents the effects of an increase or a decrease of a power reserve by load flow calculations under the seasonal load patterns of each country for the future power shortages faced by the metropolitan areas or by the southeastern area of South Korea in North-East Asia. In this paper, the various cases of the power system interconnections in Far-East Asia are presented, and the resulting interconnected power systems are simulated by means of a power flow analysis performed with the PSS/E 28 version tool. Data for simulation were obtained from the 2-th long term plan of electricity supply and demand in KEPCO. The power flow map is drawn from simulated data and the comparative study is done. In the future, a power flow analysis will be considered to reflect the effects of seasonal power exchanges. And the plan of assumed scenarios will be considered with maximum or minimum power exchanges during summer or winter in North-East Asian countries.

• KIEE International Transactions on Power Engineering
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• 제5A권1호
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• pp.62-69
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• 2005

The optimal design of transmission system expansion planning is an important part of the overall planning task of electric power system under competitive electricity market environments. One of main keys of the successful grid expansion planning comes from optimal reliability level/criteria decision, which should be given for constraint in the optimal expansion problem. However, it's very difficult to decide logically the optimal reliability criteria of a transmission system as well as generation system expansion planning in a society. This paper approaches a methodology for deciding the optimal reliability criteria for an optimal transmission system expansion planning. A deterministic reliability criteria, BRR (Bus Reserve Rate) is used in this study. The optimal reliability criteria, BRR/sup */, is decided at minimum cost point of total cost curve which is the sum of the utility cost associated with construction cost and the customer outage cost associated with supply interruptions for load considering bus reserve rate at load buses in long term forecasting. The characteristics and effectiveness of this methodology are illustrated by the case study using IEEE-RTS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.406-408
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• 2000

Recently, Korea's electric industry is in the midst of a period of profound changes in the structure and function, including the introduction of market competition in the generation sector. Therefore, it is difficult to promote long-term capacity planning and new generating capacity construction which have been driven by KEPCO so far, after the introduction of market competition, so new generating capacity construction and security of reserve margin is needed through self·regulation plan of private generation producers by market mechanism. According to the competition in the generation sector, a new paradigm is necessary to the long-term capacity planning driven by the Government. This paper analyzes the plan and the incentive level able to guide the new generation capacity construction considering the uncertainty risk in a period of introduction of competition. In addition, this paper analyzes the plan able to guide the new capacity construction by market function at the stage which market become established and Government's role to solve the anxiety about the capacity supply and demand.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.386-392
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• 1997

Recently, according to developing industry and life style, power consumption have been increased year after year. Currently these much power demand from power consumer is weakening the allowable power reserve margin in summer. As one of the remedies about this problem, the small scale utility interactive photovoltaic system(UIPVS) is considered for auxiliary power source. For this system one of problems to be solved technically, system operating power factor. Generally in case of small scale system, system is operated in unity power factor. But this unity power factor operating mode decrease power factor viewed from utility because UIPVS supply active power to utility. Therefore this paper propose UIPVS with power factor correcting function and this system is analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.309-311
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• 2008

This paper introduces the characteristics of relationship between probabilistic reliability (LOLE; Loss of Load Expectation) and deterministic reliability (SRR; supply reserve rate) for 2008 year in Korea power system. Korea power system has been using the LOLE criterion to determine the adequacy of installed capacity (ICAP) requirement. The criterion is that load shall not exceed the avaliable capacity, on the average, more than five day in ten years. The probabilistic reliability evaluation and production cost simulation program which is called PPHFHT was used in order to obtain the relationship in this paper.

• 전기학회논문지
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• 제59권8호
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• pp.1366-1373
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• 2010

Purpose of the electric power system planning and operation is to supply the electric energy to customers continuously and economically. With the mutual exclusive laws of nature between reliability and economic, finding the meeting point is very important but not easy. Commonly the probabilistic reliability indices of the electric power systems are represented with negatively. And the effectiveness of FACTS on the probabilistic reliability could not be reflected with common methods. In this paper, a method to evaluate the probabilistic arrival power at each load point is presented. With this new proposed method, probabilistic reserve margin at load points can be calculated and which can be used with positive reliability index also. Using the P-V analysis, the voltage stability is considered in reliability evaluation. It is expected that the proposed method will be useful expecially in reliability evaluation of electric power system which has voltage restriction.

• 전기학회논문지
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• 제61권4호
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• pp.534-541
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• 2012

This paper tries to elicit an optimal generation mix of Korea. Two approaches, using the screening curve method and taking advantage of a generation expansion planning tool, WASP-IV, are applied in getting the mix. The data used in this study is based on the 5th basic plan for long-term electricity supply and demand. The Load Duration Curve, that is needed for applying Screening Curve Method(SCM), is made based on the load profile in 2010. In our using SCM, the nuclear plant's operation characteristic, carbon emission cost and spinning reserve are considered. In using WASP-IV to get the adequate generation mix, the base and target demand forecasts in the 5th basic plan are used and the carbon emission cost is also considered. In this paper, It introduces the domestic adequacy generation mix in 2024 though SCM and WASP-IV.