• KIEE International Transactions on Power Engineering
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• 제5A권3호
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• pp.300-302
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• 2005

We employ a new technique to account for extreme values when using the generalized autoregressive conditionally heteroskedastic (GARCH) methodology to forecast day-ahead electricity prices in New York City.

• KIEE International Transactions on Power Engineering
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• 제5A권2호
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• pp.193-198
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• 2005

This paper proposes a new method to handle transmission line losses using loss distribution factors (LDF) rather than marginal loss factors (MLF) in electricity market operation. Under a competitive electricity market, the bidding data are adjusted to reflect transmission line losses. To date the most proposed approach is using MLFs. The MLFs are reflected to bidding prices and market clearing price during the trading and settlement of the electricity market. In the proposed algorithm, the LDFs are reflected to bidding quantities and actual generations/ loads. Computer simulations on a 9-bus sample system will verify the effectiveness of the algorithm proposed. Moreover, the proposed approach using LDFs does not make any payments residual while the approach using MLFs induces payments residual.

• 대한전기학회논문지:전력기술부문A
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• 제52권6호
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• pp.340-346
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• 2003

This paper presents a game theory application for an analysis of uniform price auction in a simplified competitive electricity market and analyzes the properties of Nash equilibrium for various conditions. We have assumed that each generation firm submits his bid to a market in the form of a sealed bid and the market is operated as a uniform price auction. Two firms are supposed to be the players of the market, and we consider the maximum generation quantity constraint of one firm only. The system demand is assumed to have a linear relationship with market clearing prices and the bidding curve of each firm, representing the price at which he has a willingness to sell his generation quantity, is also assumed to have a linear function. In this paper, we analyze the effects of maximum generation quantity constraints on the Nash equilibrium of the uniform price auction. A simple numerical example with two generation firms is demonstrated to show the basic idea of the proposed methodology.

• 대한전기학회논문지:전력기술부문A
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• 제52권4호
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• pp.234-239
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• 2003

In recent decades, many countries have introduced competition in the electricity industry. Now, unit commitment becomes not a problem to be solved by a monopoly company but the one to be tackled by each generation company(GENCO). Its aim has been altered from the global cost minimization to the each GENCO's profit maximization. In this paper, the author proposes the scheme of unit commitment of a GENCO to maximize profit considering the uncertainty of market clearing price. The type of the assumed market is a uniform price market. A genetic algorithm is used for the maximization of the profit.

• 대한전기학회논문지:전력기술부문A
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• 제51권12호
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• pp.638-646
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• 2002

This paper presents an efficient algorithm for evaluating the Profit and revenue of generating units in a competitive electricity market based on the probabilistic production costing technique. The accurate evaluation of the profit and revenue of generating units for long-term perspectives is one of the most important issues in a competitive electricity market environment. For efficient calculation of the profit and revenue of generating units under the equivalent load duration curve(ELDC), a new approach to figure out the marginal plants and the corresponding market clearing prices during a time period in a probabilistic manner is developed. The mathematical formulation and illustrative application of the suggested method is presented.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1480-1491
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• 2015

In new deregulated electricity market, short-term price forecasting is key information for all market players. A better forecast of market-clearing price (MCP) helps market participants to strategically set up their bidding strategies for energy markets in the short-term. This paper presents a new prediction strategy to improve the need for more accurate short-term price forecasting tool at spot market using an artificial neural networks (ANNs). To build the forecasting ANN model, a three-layered feedforward neural network trained by the improved Levenberg-marquardt (LM) algorithm is used to forecast the locational marginal prices (LMPs). To accurately predict LMPs, actual power generation and load are considered as the input sets, and then the difference is used to predict price differences in the spot market. The proposed ANN model generalizes the relationship between the LMP in each area and the unconstrained MCP during the same period of time. The LMP calculation is iterated so that the capacity between the areas is maximized and the mechanism itself helps to relieve grid congestion. The addition of flow between the areas gives the LMPs a new equilibrium point, which is balanced when taking the transfer capacity into account, LMP forecasting is then possible. The proposed forecasting strategy is tested on the spot market of the Nord Pool. The validity, the efficiency, and effectiveness of the proposed approach are shown by comparing with time-series models

• KIEE International Transactions on Power Engineering
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• 제3A권1호
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• pp.53-60
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• 2003

At present the electric power industry in Korea is going through a major restructuring process. The restructuring is motivated by a desire to reduce electricity supply costs, to attract new in-vestment in modern generation, transmission and distribution facilities, and to stimulate innovation in the wholesale production and the retail supply of electricity. The experience to date shows that restructuring of electric power industry in the US, however, is marred with a number of problematic market performances including unreasonably high prices at wholesale. This paper investigates the important role of Power Exchange for stabilizing electric power industry in transition by offering various financial products. These financial products are used for risk hedging by the market participants. The paper focuses on the risk hedging by an individual supplier and derives an explicit decision rule that incorporates the attitude towards the risks. In addition to providing the financial products for risk hedging by market participants, the Power Exchange plays another very important role of financial safeguard system. Because of its unique characteristics, the Power Exchange is well suited for financial surveillance where it performs the early detection of unsound financial (and to a large extent operational) practices on the part of any system users and protect the system integrity and the market participants from the consequences of a default in the clearing structure.

• 한국식생활문화학회지
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• 제6권4호
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• pp.403-411
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• 1991

A survey was made, from May to June 1991, to reveal the current situation of the meal management of the homemakers in Jeonbuk area. The results obtained from 464 homemakers were summerized as follows. The meal expenses were planned and managed mostly by the homemakers (93.3%). The 31.1% homemakers expended 200,000-300,000 Won a month for meals and the average expenditure was 294,106 Won. Among the homemakers who responded, the 34.0% managed their account books for meal expenses. With decreasing age(p<0.05), increasing education level (p<0.001), and increasing the income(p<0.01), the number of those who managed the account book tended to be higher. Usually they bought their foods at the market place (52.1%) and they did every other days(33.2%). The 46.9% planned what to buy and chose the best ones among the foods they planned to buy at the market. The percentage of those who prepared their menus planned in advance was only 5.5%. The most homemakers cooked for themselves (96.8%). On cooking and buying foods, the 48.2% considered their husbands first and the 64.4% regarded the tastes and needs of their families as the most important thing. The majority (66.2%) regarded the dinner as the most important among those three times of meals. The 39.6% prepared Kimchi twice a month. The foods they prepared for each meal were usually 4-5 kinds (43.2%). Mostly they prepared meals three times a day (49.1%). The average times spent in preparing and cleaning the tables for lunch and breakfast were 41.6, 96.2 minutes respectively. The homemakers who had jobs tended to spend less time in preparing and clearing the tables than those who had not (p<0.01, p<0.001). The 58.0% had complaints in that the food prices were too high and their moneys for meal preparation were insufficient and the 16.6% had difficulty in satisfying the tastes of their families.

• 자원ㆍ환경경제연구
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• 제24권3호
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• pp.573-605
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• 2015

본 논문은 2014년 7월과 2015년 7월부터 시행된 발전용 유연탄 과세와 LNG 세율 변경을 중심으로 세제 개편의 시나리오들을 설정하여 2029년까지의 SMP, 정산단가, 조세수입에 대한 영향을 추정하고, 시나리오 1(기준시나리오)의 값들과 비교하였다. 추정에서는 우리나라의 전력계통과 전력시장 운용방식에 특화한 모형과 전력수급기본계획 등의 정부 계획자료를 이용하여 전력계통 모의 실험을 실시하였다. 발전용 유연탄에 과세하고 조세중립성을 확보하기 위해 LNG에 대해서도 과세하는 경우에 단기에 SMP는 시나리오 1의 경우에 비해서 낮아진다. 원자력발전의 경우는 과세를 하여도 발전비용이 다른 발전원의 발전비용보다 작고, 원자력발전이 SMP를 결정하는 시간대가 거의 없기 때문에 과세가 SMP에 미치는 영향은 거의 없다. 따라서 SMP와 정산단가의 동조화관계가 성립한다면, 단기에 발전용 유연탄에 대한 과세로 에너지소비의 전력화현상을 둔화시키기는 어렵다. 그러나 중 장기에는 석탄발전설비가 충분히 확보되면 발전용 유연탄에 대한 과세는 SMP를 상승시키므로 세제 개편의 형태가 단기에 발전용 유연탄에만 과세하고 신규 유연탄 발전설비가 충분히 도입된 이후에 LNG에 대한 세율을 조정하면 에너지세제 개편으로 전기요금을 인상시켜서 전력수요를 감소시키려는 목적은 달성할 수 있을 것이다. 중 장기에는 발전설비의 확충으로 LNG복합발전기의 이용률이 낮아지므로 LNG에 대한 세율이 정산단가에 영향을 미치지 못한다. 원자력발전에 대한 과세는 SMP에 대한 영향과는 달리 정산조정계수의 영향으로 정산단가를 상승시켰다. 중 장기에 에너지세제가 갖는 순효과는 전력공급력의 확대에 따른 정산단가 하락이 에너지세제 부과에 따른 정산단가 상승을 상쇄시키는 정도에 따라서 달라질 것이다. 과세대상 중에서 원자력발전의 경우에 과세하는 경우에 추가적으로 발생하는 조세수입이 가장 컸다. 에너지세제의 형태와 조세수입의 관계를 보면 발전용 유연탄에 대한 세율이 높을수록, 그리고 원자력발전에 신규로 조세를 부과할수록 조세수입은 커진다.