• Title, Summary, Keyword: Load

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The Optimal Load Curtailment of Urban Railway Load (도시 철도 부하의 최적 부하 차단)

  • Heo, Jae-Haeng;Kim, Hyungchul;Shin, Seungkwon;Park, Jong-young;Kim, Hyeongig
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.9
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    • pp.1610-1617
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    • 2016
  • To execute load curtailment efficiently for Urban Railway Load, the load patterns of the Urban Railway Load and available amount of load curtailment over the Urban Railway Load are analyzed through comparing the load to the common power loads. In addition, the current policies of the load curtailment for the Urban Railway Load are investigated and the problems of those are presented. Based on the researches, the optimal load curtailment strategies for the Urban Railway Load are proposed to minimize the consumer's utility diminishment and the costs of the use of energies. Finally, the optimal load curtailment strategies are applied to the real Urban Railway Load, the results shows that proposed methods are efficient and cost effective while the amount of load curtailment is minimized.

A Study on the Seasonal Load Characteristics in 22.9[kV] Bus (22.9[kV] 모선의 계절별 부하특성에 관한 연구)

  • 이종필;임재윤;지평식;김기동;김정훈
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.6
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    • pp.279-286
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    • 2001
  • A load modeling, micro method, is performed by component load modeling, load composition rate estimation and aggregation of component load model, etc. The load model obtained from this process must be applied to actual load bus to verify it and to get reliable load model. But it is difficult to apply every load bus due to al lot of load buses and complex experiment. This paper proposed the field test method in load bus to verify the load modeling. For appropriate field test, representative load buses are selected by the proposed algorithm considering the composition rate of user category in all load buses. The field tests were performed at selected load buses to obtain load characteristics of bus by time and seasonal without blackout. The results of measurement and analysis are presented in detail.

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Studies on the Influence of Sample thickness, Load Increment Ratio and Load Increment Duration on Consolidation Characteristics. (시료의 두께, 하중증가율 밀 재하시간이 압밀특성에 미치는 영향)

  • 류능환;강예묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.20 no.3
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    • pp.4750-4770
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    • 1978
  • Under the various variations of the sample thickness, the load increment ratio and the load increment duration, this consolidation test of the clay in the Asan Bay was tried for the comparison with the standard consolidation test. The results gained are as follows; 1. The void ratio variations of the leached-clay samples were increasingly high, according as the sample thickness thinned and the load increment duration and the laod increment ratio increased. 2. The coefficient of consolidation were increased with the increment of the sample thickness, of the load increment ratio and of the load increment duration. Near the pre-consolidation load, the coefficient of secondary consolidation had the maximum value and lessened with the increment of the sample thicknss, and of the load increment duration 3. The value of the pre-consolidation load increased in proportion to the increment of the sample thickness and the decrease of the load increment ratio and the load increment duration. 4. The compression indices increased as the increment of load increased and decreased as the sample thickness increased. 5. The initial compression ratio increased as the sample thickness, the load increment ratio and the load increment duration decreased. The ratio of primary compression to the secondary decreased with the increment of the sample thickness and of the load increment ratio. 6. The time at the completion of psimary consolidation increased with the increment of the sample thickness and of the consolidation load, and with the decrease of the load increment ratio. 7. The compression indicses increaed as the sample thickness lessened and decreased as the load increment ratio increased. The coefficient of consolidation increased according as the sample thickness, the load increment ratio and the load increment duration went up. The settlement at the construction site should be calculated highly in proportion as the sample thickness lessened and the load increment ratio increased. The consolidation ratio is thought to be accelerated if the sample thickness and the load increment ratio becomes higher and the load increment duration longer.

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Load Forecasting and ESS Scheduling Considering the Load Pattern of Building (부하 패턴을 고려한 건물의 전력수요예측 및 ESS 운용)

  • Hwang, Hye-Mi;Park, Jong-Bae;Lee, Sung-Hee;Roh, Jae Hyung;Park, Yong-Gi
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.9
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    • pp.1486-1492
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    • 2016
  • This study presents the electrical load forecasting and error correction method using a real building load pattern, and the way to manage the energy storage system with forecasting results for economical load operation. To make a unique pattern of target load, we performed the Hierarchical clustering that is one of the data mining techniques, defined load pattern(group) and forecasted the demand load according to the clustering result of electrical load through the previous study. In this paper, we propose the new reference demand for improving a predictive accuracy of load demand forecasting. In addition we study an error correction method for response of load events in demand load forecasting, and verify the effects of proposed correction method through EMS scheduling simulation with load forecasting correction.

A study on case analysis for loading capacity standard establishment of bi-directional pile load test (BD PLT) (양방향말뚝재하시험의 재하용량 기준 설정을 위한 사례분석 연구)

  • Choi, Yong-Kyu;Seo, Jeong-Hae;Kim, Sang-Il
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.377-384
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    • 2008
  • In the bi-directional pile load test (BD PLT) for pile load test of Mega foundation, loading capacity specification were not specified exactly. Therefore there are so many confusions and variations of maximum 2 times in loading capacity are come out. In this study, specifications of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio and sufficiency ratio of design load were analyzed. It can be known that the loading capacity specification of bi-directional pile load test must be defined as 1-directional test load that is established as more than 2 times of design load.

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A Study on a Substation Static Load Model Including the Mobility of a Railway Load (철도 부하의 이동성을 반영한 변전소 정태부하모델링 수립에 대한 연구)

  • Chang, Sang-Hoon;Youn, Seok-Min;Kim, Jung-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.2
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    • pp.315-323
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    • 2015
  • Nowadays, it is expected that mobility loads such as electric railways and electric vehicles will be penetrated gradually and affect on the power system stability by their load characteristics. Various researches have been carried out about electric vehicles for the recent decade though the load of electric railway could be forecasted because of the specified path and timetable, is a field with a long historic background. Some precise 5th polynomial equations are required to analyze the power system stability considering mobility load to be increased in the immediate future while the electric railway dispatching simulator uses load models with constant power and constant impedance for the system analysis. In this paper, seasonal urban railway load models are established as the form of 5th polynomial equations and substation load modeling methods are proposed merging railway station load models and general load models. Additionally, load management effects by the load modeling are confirmed through the case studies, in which seasonal load models are developed for Seoul Subway Line No. 2, Gyeongui Line and Airport Railroad and the substation load change is analyzed according to the railway load change.

2-Step Modeling for Daily Load Curve of Up to and Including 100kVA Distribution Transformer (100kVA 이하급 배전용 변압기 일부하 패턴의 2-Step 모델링)

  • Lee, Young-Suk;Kim, Jae-Chul;Yun, Sang-Yun
    • Proceedings of the KIEE Conference
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    • pp.371-373
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    • 2001
  • In this paper, we present 2-step load cycle for daily load curve of up to and including 100kVA distribution transformer in domestic. Daily load patterns are classified by two methods dependent upon possession information. In case we possess daily load profiles make use of K-mean algorithm and in case we have not daily load profiles, make use of customer information of KEPCO. As the parameters of the load pattern classification, we use are daily load profiles and customer information of each distribution transformers. Data management system is used for NT oracle. We can present peak load magnitude, initial load magnitude and peak load duration for daily load patterns by 2-step load cycle for daily load curve of up to and including 100kVA distribution transformer in domestic. We think that this paper contributes to enhancing the distribution transformer overload criterion.

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Model Development of Daily and Hourly Energy Load for Department Stores

  • Park Hwa-Choon;Lee Sung-Soo;Kim Dae-Jin
    • International Journal of Air-Conditioning and Refrigeration
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    • v.12 no.4
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    • pp.169-175
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    • 2004
  • Case study was performed to analyze energy load for department stores and develop energy load model to be applied to a cogeneration system. Energy loads of 14 depart­ments were analyzed based on energy load sheets written by operators and energy load of one department store was measured through modem communication for a year. Energy load of department stores showed various trends depending on when they were opened or closed, or by hour, day and month. In this paper, the measurement was compared with the data in energy load sheets and resolved, and energy load model for a department store was built. It is important to use an accurate energy load model for an accurate feasibility study applying a cogeneration system to buildings.

A Study on the Weekend Load Forecasting of Jeju System by using Temperature Changes Sensitivity (제주계통의 기온변화 민감도를 반영한 주말 전력수요예측)

  • Jeong, Hui-Won;Ku, Bon-Hui;Cha, Jun-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.5
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    • pp.718-723
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    • 2016
  • The temperature changes are very important in improving the accuracy of the load forecasting during the summer. It is because the cooling load in summer contribute to the increasing of the load. This paper proposes a weekend load forecasting algorithm using the temperature change characteristic in a summer of Jeju. The days before and after weekends in Jeju, when the load curves are quite different from those of normal weekdays. The temperature change characteristic are obtained by using weekends peak load and high temperature data. And load forecasted based on the sensitivity between unit temperature changes and load variations. Load forecast data with better accuracy are obtained by using the proposed temperature changes than by using the ordinary daily peak load forecasting. The method can be used to reduce the error rate of load forecast.

Model Development of Daily and Hourly Energy Load for Department Stores (백화점 건물의 에너지 부하모델 개발)

  • 박화춘;이승수;김대진
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.12
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    • pp.1088-1094
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    • 2003
  • Case study was peformed to analyze energy load for department stores and develop energy load model to be applied to a cogeneration system. Energy loads of 14 departments were analyzed based on energy load sheets written by operators and energy load of one department store was measured through modem communication for a year. Energy load of department stores shows various variations depending on when they are opened or closed and, hours, days and months. In this paper, the measurement was compared with data in energy load sheets and resolved, and energy load model for a department store was built. It is important to use an accurate energy load model for an accurate feasibility study applying a cogeneration system to buildings.