• 전기학회논문지
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• 제63권1호
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• pp.27-34
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• 2014

The paper proposed a sizing method of an energy storage system(ESS) for peak shaving of high-speed railway substations based on load profile patterns of substations. A lithium based battery ESS was selected since it can produce high-power at high speed that peak shaving requires, and also takes up a relatively smaller space for installation. Adequate size of the ESS, minimum capacity which can technically meet a peak shaving target, was determined by collectively considering load patterns of a target substation, characteristics of the ESS to be installed, and optimal scheduling of the ESS. In case study, a local substation was considered to demonstrate the proposed sizing method. Also economic analysis with the determined size of ESS was performed to calculate electricity cost savings of the peak shaving ESS, and to offer pay-back period and return on investment.

• 디지털융복합연구
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• 제18권12호
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• pp.267-278
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• 2020

에너지 패러다임이 격변하는 시점에서 ESS는 전력부족 및 전력수요관리의 해소와 재생에너지의 증진에 필수적인 요건이다. 이에 본 논문에서는 부하 및 태양광 발전 예측량을 통하여 비용효과적인 ESS Peak-Shaving 운영방안을 제안한다. ESS 운영방안을 위해 통계적 척도인 RMS을 통해 부하 및 태양광 발전 예측하였으며 예측된 부하 및 태양광 발전량을 통해 한 시간 단위의 목표 부하 절감량 Guide-line을 설정하였다. 대상 수용가의 1년 실데이터를 활용한 부하 및 태양광 발전 예측 시뮬레이션으로 2019년 5월 6일 ~ 10일의 부하 및 태양광 발전량을 예측 하였으며 시간별 Guide-line을 설정하였다. 부하 예측 평균오차율은 7.12%였으며, 태양광 발전량 예측 평균오차율은 10.57%를 나타냈다. ESS 운영방안을 통한 시간별 Guide-line 제시를 통해 수용가의 Peak-shaving 최대화에 기여하였음을 확인하였다. 본 논문의 결과를 통해 태양광과 연계하여 화석에너지로 발생하는 환경적인 영향을 최소화하며 신재생에너지를 최대 활용하여 에너지 문제를 줄일 수 있다고 기대한다.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1125-1131
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• 2014

Application of residential demand response (DR) programs are currently realized up to a limited extent due to customers' difficulty in manually responding to the time-differentiated prices. As a solution, this paper proposes an automatic home load management (HLM) framework to achieve the household minimum payment as well as meet the operational constraints to provide customer's comfort. The projected HLM method controls on/off statuses of responsive appliances and the charging/discharging periods of plug-in hybrid electric vehicle (PHEV) and battery storage at home. This paper also studies the impacts of different time-varying tariffs, i.e., time of use (TOU), real time pricing (RTP), and inclining block rate (IBR), on the home load management (HLM). The study is effectuated in a smart home with electrical appliances, a PHEV, and a storage system. The simulation results are presented to demonstrate the effectiveness of the proposed HLM program. Peak of household load demand along with the customer payment costs are reported as the consequence of applying different pricings models in HLM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.720-723
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• 1996

The recent summer power peak crisis has been caused by excessive use of cooling loads at daily peak time in summer. The yearly load shape of KEPCO has gradually became very steep valley. Under this situation, more efficient DSM(Demand Side Management) tools are fully required for summer peak clipping and shaving. In this paper, the KEPCO's Jeju-Do model project for DSM, especially for Demand Controller, is presented. Demand Controller was evaluated to have the very high economical efficiency against the investment in equipment, as compared with another DSM tools. There were some serious problem to apply Demand Controller to many customers in the aspect to synchronization with KEPCO's watthour meter. But these problems have solved by Keyin's new Demand Controller using vision algorithm.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.85-92
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• 2018

수요관리를 통해 전기요금을 절감할 수 있다. 부하의 수요 관리 방법 중 하나로 ESS를 설치해 수요가 높은 시간대의 부하를 수요가 낮은 시간대로 옮기는 peak shifting을 사용함으로써 최대 부하를 낮추고 전력량 요금을 절감할 수 있다. 전기요금은 계약 용량 당 기본요금과 전력량 요금으로 이루어져있다. 전력량 요금을 최소화하기 위한 최적화 수행시 목적함수는 선형식으로 표현할 수 있으며, 기본 요금 최소화를 위한 목적함수는 이차식으로 표현할 수 있다. 선형식으로 표현된 목적함수에서는 ESS PCS(Power Conversion System)의 충, 방전 효율이 다른 경우를 다룰 수 없기 때문에 본 논문에서 충, 방전 효율이 다른 경우의 영향을 반영하고 혼합정수계획법(MILP, Mixed Integer Linear Programming)을 이용할 수 있는 정식을 제시하였다. 혼합정수계획법을 사용한 정식에서는 사전에 정해진 최대 부하 절감율에 대해 전기요금 최소화를 수행하게 되지만 최대 부하 절감과 전기요금 절감을 동시에 고려하기 위해서는 이차 계획법을 사용하는 것이 유용하다. 본 논문에서는 각 최적화 방법에 대한 장, 단점을 도시철도 변전소에 대한 시뮬레이션 결과를 정량적으로 비교분석하여 ESS 설비계획수립에 적합한 최적화 방법을 선택할 수 있는 근거를 제시하였다.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1296-1304
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• 2013

This study performed an analysis on power demand reduction effects exhibited by demand response programs, which are advanced from traditional demand-side management programs, in the smart grid environment. The target demand response systems for the analysis included incentive-based load control systems (2 month-ahead demand control system, 1~5 days ahead demand control system, and demand bidding system), which are currently implemented in Korea, and price-based demand response systems (mainly critical peak pricing system or real-time pricing system, currently not implemented, but representative demand response systems). Firstly, the status of the above systems at home and abroad was briefly examined. Next, energy saving effects and peak demand reduction effects of implementing the critical peak or real-time pricing systems, which are price-based demand response systems, and the existing incentive-based load control systems were estimated.

• 스마트미디어저널
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• 제8권4호
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• pp.72-79
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• 2019

The automated demand response (DR) program encourages consumers to participate in grid operation by reducing power consumption or deferring electricity usage at peak time automatically. However, successful deployment of the automated DR program sphere needs careful assessment of appliances load profile (ALP). To this end, the recent method estimates frequency, consistency, and peak time consumption parameters of the daily ALP to compute their potential score to be involved in the DR event. Nonetheless, as the daily ALP is subject to varying with respect to the DR time ALP, the existing method could lead to an inappropriate estimation; in such a case, inappropriate appliances would be selected at the automated DR operation that effected a consumer comfort level. To address this challenge, we propose a more proper method, in which all the three parameters are calculated using ALP that overlaps with DR time, not the total daily profile. Furthermore, evaluation of our method using two public residential electricity consumption data sets, i.e., REDD and REFIT, shows that our energy management systems (EMS) could properly match a DR target. A more optimal selection of appliances for the DR event achieves a power consumption decreasing target with minimum comfort level reduction. We believe that our approach could prevent the loss of both utility and consumers. It helps the successful automated DR deployment by maintaining the consumers' willingness to participate in the program.

• 전기학회논문지
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• 제60권12호
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• pp.2202-2205
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• 2011

Demand side management is used to maintain the reliability of power systems and to increase the economic benefits by avoiding power plant construction. This paper presents a systematic method to calculate the quantity of seasonal demand side management using time series. A numerical example is presented to calculate the quantity of demand side management in winter season using time series.

• 전기학회논문지
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• 제63권11호
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• pp.1608-1614
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• 2014

Power demand forecasting is an important factor of the peak management. This paper deals with the 15 minutes ahead load forecasting problem in a DC urban railway system. Since supplied power lines to trains are connected with parallel, the load characteristics are too complex and highly non-linear. The main idea of the proposed method for the 15 minutes ahead prediction is to use the daily load similarity accounting for the load nonlinearity. An Euclidean norm with weighted factors including loads of the neighbor substation is used for the similar load selection. The prediction value is determinated by the sum of the similar load and the correction value. The correction has applied the neural network model. The feasibility of the proposed method is exemplified through some simulations applied to the actual load data of Incheon subway system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.264-265
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• 2006

This paper presents direct load control algorithm based locational and electric load characteristics. Direct load control is defined that demand-side management program activities that can interrupt consumer load at the time of annual peak load by direct control of the utility system operator by interruption power supply to individual appliances or equipment on consumer premises. Korean power system is divided into 14-areas considering branches operating in KEPCO, and electric loads are classified into 19 load groups considering interruption costs in this paper. The purpose of proposed method is to decrease social losses by controlling electric loads mainly whose interruption costs are low. It is expected that the proposed algorithm can be used as the countermeasure for the emergency state of the electric power dispatch in a operation point of view.