• Title/Summary/Keyword: Electric charges

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Operation Algorithm of Battery Energy Storage System (BESS) for Saving Electric Charges (전기요금 절감 측면에서 에너지저장시스템의 운전알고리즘)

  • 김응상
    • Journal of Energy Engineering
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    • v.8 no.4
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    • pp.519-524
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    • 1999
  • this paper proposes the operation algorithm of 1MW class Battery Energy Storage System(BESS) installed at the extra-high voltage customer. The objective of the proposed algorithm is to reduce electric charges during the operation of the BESS interconnected to power system. This paper simulates the electric charges in 1998 considering Season and Time of Use Rate and Power Factor in the assumption that electricity demand in 1998 is the same amount of that in 1997 and shows the saving of about 40 million won in the total electric charges. The results comparing the real electric charges of June. July and August in 1997 with that in 1998 show that the implementation of the proposed algorithm could significantly reduce electric charges during the operation the BESS.

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Optimal Capacity Determination of BESS for Customer using Investment Cost and Electric Cost (투자비용과 전기요금을 반영한 수용가 BESS의 최적용량 산정)

  • Park, Jin-Kyung;Baek, Young-Sik;Jeong, Ki-Seok;Park, Ji-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.2
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    • pp.208-213
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    • 2015
  • This study presents the estimation method for the optimal capacity of BESS(Battery Energy Storage System) in order to reduce the electric charges of common consumer. The daily optimal charge and discharge plan of BESS which satisfies the given constraints is established using linear programming through the change of rated output/rated capacity of the time that shows the electric charges in the highest reduced rate has been selected. There will be a problem to compare only reduced rate because the bigger the rated capacity, the more reduced rate is increased. Therefore, rated output/rated capacity of the time when the reduced amount of electric charges for a year is higher than the investment cost of BESS was selected.

Are Particulate Filtering Respirators Available in Korea Efficient for Nanoparticles? (<종설>국내 시판 방진마스크는 나노입자에 적합한가?)

  • Han, Don-Hee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.21 no.1
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    • pp.62-71
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    • 2011
  • There is widespread concern that particulate filtering respirators (PFRs) available in Korea will be efficient for nanoparticles. The purpose of this review study was to analyse research literature and recommend PFRs suitable for protection against nanoparticles. In all studies, respirators containing electret filter media (N95, P100 and FFP2, FFP3) consistently have their MPPS below 100 nm and particle penetration levels at the MPPS can vary widely, but they comply with NIOSH or EN certification criterion. Electret filtering facepieces respirators (FFRs) were found to shift in the Most-Penetrating Particle Size(MPPS) from 30-60 to 200-300 nm range after the electric charges were removed, and FFRs were above their minimum penetrations of criterion. Korean special class and first class FFRs (the same as FFP3 and FFP2, respectively) would be effcient for nanoparticles unless FFRs are removed electric charges. It is difficult to evaluate if mechanical PFRs is efficient for nanoparticles due to the lack of related materials.

Economic Analysis of Heating and Cooling System Corresponding to the Energy Cost of University Building (대학건물에서 에너지비용 변화에 따른 히트펌프 냉난방시스템에 대한 경제성 분석)

  • Kim, Dong-Wan
    • Journal of the Korean Institute of Educational Facilities
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    • v.16 no.1
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    • pp.43-50
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    • 2009
  • This research is to analyze LCC of Heat Pump system in university building by reduction of electric power costs for education and incentive system for gas. Produced details item different expense of EHP and GHP equipment construction step and preservation administration step. Analysis result is as following. 1) Executed LCC analysis for target system after lowering whole curriculum reduction of electric power costs for education. Analysis result, energy cost-cutting effect of EHP appears greatly than GHP unlike existent study finding, EHP decided by economical system. 2) Sensitivity analysis executed by incentive 500,000 won per units and geometrical ration of gas expense by 1%. As a result, because lowering effect of electric charges appears greatly, EHP decided by more economical system than GHP. As research result of front is different from existent study finding, EHP by lowering of electric charges for alteration and education of governmental frequent volunteer system was decided by more economical system than GHP.

Optimal Voltage and Reactive Power Scheduling for Saving Electric Charges using Dynamic Programming with a Heuristic Search Approach

  • Jeong, Ki-Seok;Chung, Jong-Duk
    • Journal of Electrical Engineering and Technology
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    • v.11 no.2
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    • pp.329-337
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    • 2016
  • With the increasing deployment of distributed generators in the distribution system, a very large search space is required when dynamic programming (DP) is applied for the optimized dispatch schedules of voltage and reactive power controllers such as on-load tap changers, distributed generators, and shunt capacitors. This study proposes a new optimal voltage and reactive power scheduling method based on dynamic programming with a heuristic searching space reduction approach to reduce the computational burden. This algorithm is designed to determine optimum dispatch schedules based on power system day-ahead scheduling, with new control objectives that consider the reduction of active power losses and maintain the receiving power factor. In this work, to reduce the computational burden, an advanced voltage sensitivity index (AVSI) is adopted to reduce the number of load-flow calculations by estimating bus voltages. Moreover, the accumulated switching operation number up to the current stage is applied prior to the load-flow calculation module. The computational burden can be greatly reduced by using dynamic programming. Case studies were conducted using the IEEE 30-bus test systems and the simulation results indicate that the proposed method is more effective in terms of saving electric charges and improving the voltage profile than loss minimization.

Development of optimal algorithm for PV-ESS integrated system by 3 Dimensional Dynamic Programming (3차원 동적계획법에 의한 PV-ESS 연계형 시스템의 최적운용 알고리즘 개발)

  • Choi, You-Rim;Lim, Tae-Hun;Jung, Jea-Hoon;Kim, Yong-Ha
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.1027-1032
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    • 2019
  • In this paper, we had developed an algorithm that can cope with all the economic variables that may occur in the operation of PV-ESS system by developing the algorithm for the operation method of PV-ESS connected system. Based on this, the optimal operation schedule of PV-ESS was decided to minimize the electric charges of customers. Through this, we developed a three-dimensional dynamic planning method based on case generation to determine the optimal PV-ESS operation schedule stably even when exogenous variables change.

A Study on Application of Geothermal Heatpump System for Apartments (공동주택용 지열냉난방 적용성 검토 연구)

  • Baek, Sung-Kwon;Ahn, Hyung-Jun;Lee, Dong-Cheul;Im, Seung-Kyun
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.574-578
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    • 2009
  • Residential is the biggest market for geothermal heatpump systems in the world. However It could not be considered as a big market in Korea. Serious problems are hidden. In this paper, I will discuss about with other problems that we must solve.

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Development of MS Excel Macros to estimate regression models and test hypotheses of relationships between variables (Application to regression analysis of subway electric charges data) (MS Excel 함수들을 이용한 회귀 분석 모형 추정 및 관계 분석 검정을 위한 매크로 개발 (지하철 전기요금 자료 회귀분석에 응용))

  • Kim, Sook-Young
    • Journal of the Korea Computer Industry Society
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    • v.10 no.5
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    • pp.213-220
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    • 2009
  • Regression analysis to estimate the fitted models and test hypotheses are basic statistical tools for survey data as well as experimental data. Data is collected as pairs of independent and dependent variables, and statistics are computed using matrix calculation. To estimate a best fitted model is a key to maximize reliability of regression analysis. To fit a regression model, plot data on XY axis and select the most fitted models. Researchers estimate the best model and test hypothesis with MS Excel's graph menu and matrix computation functions. In this study, I develop macros to estimate the fitted regression model and test hypotheses of relationship between variables. Subway electric charges data with one dependent variable and three independent variables are tested using developed macros, and compared with the results using built-in Excel of regression analysis.

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Development of Functional Pulp Tray for Prevention of Static Electricity (정전기 방지를 위한 기능성 펄프 트레이 개발)

  • Lee, Ji-Young;Kim, Chul-Hwan;Nam, Hye-Gyeong;Park, Hyeong-Hun;Kwon, Sol;Lee, Young-Min
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.52-60
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    • 2015
  • Static electricity is an imbalance of electric charges within or on the surface of a material. All packed items that are particularly sensitive to static discharge must be protected by antistatic treatment. Otherwise, static electricity generated by an electrical insulator may cause serious damages to some sensitive electronics. In order to remove or prevent a buildup of static electricity, packed items must be treated with the application of an antistatic agent, which helps any excess charge to be evenly distributed. Functional pulp tray used for packing of electronic goods was developed with application of an antistatic agent. As the concentration of the antistatic agent increased, charging voltage and surface resistance of molded pulps decreased. The increase of humidity in surrounding atmosphere around molded pulps led to the decrease of accumulation of static charges. In conclusion, the surface treatment of the antistatic agent not only reduced or eliminated buildup of static electricity in the surface, but also prevented generation of tiny dirts from molded tray.