• Title, Summary, Keyword: Estimation of electrical energy

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A Study on Monthly Electric Energy Estimation of Pole-Transformer Using NLRE Curve (NLRE 곡선을 이용한 주상 변압기 월간 사용전력량 추정에 관한 연구)

  • Im, Jin-Soon;Yun, Sang-Yun;Kim, Jae-Chul
    • Proceedings of the KIEE Conference
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    • pp.58-60
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    • 2000
  • In this paper we present an estimation method of electric energy[kWh] for load management of pole-transformer. For the electric energy estimation, we use the nonlinear load research based estimation(NLRE) algorithm. The NLRE curve is the normalized annual cumulative energy consumption for a particular day in a year. And, it is used for the coefficient estimation. Estimation method of suggested electric energy of pole-transformer used billing cycle electric energy estimation equation is verified as comparison billing cycle electric energy and estimated electric energy. We can reduce the error of peak load estimation by suggested method than the conventional method in domestic.

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A Study on the Baseline Load Estimation Method using Heating Degree Days and Cooling Degree Days Adjustment (냉난방도일을 이용한 기준부하추정 방법에 관한 연구)

  • Wi, Young-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.5
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    • pp.745-749
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    • 2017
  • Climate change and energy security are major factors for future national energy policy. To resolve these issues, many countries are focusing on creating new growth industries and energy services such as smartgrid, renewable energy, microgrid, energy management system, and peer to peer energy trading. The financial and economic evaluation of new energy services basically requires energy savings estimation technologies. This paper presents the baseline load estimation method, which is used to calculate energy savings resulted from participating in the new energy program, using moving average model with heating degree days (HDD) and cooling degree days (CDD) adjustment. To demonstrate the improvement of baseline load estimation accuracy, the proposed method is tested. The results of case studies are presented to show the effectiveness of the proposed baseline load estimation method.

Electrical Resistance Tomography: Mesh Grouping and Boundary Estimation Algorithms

  • Kim Sin;Cho Hyo-Sung;Lee Bong-Soo
    • International Journal of Contents
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    • v.1 no.1
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    • pp.1-5
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    • 2005
  • This paper presents the development and application of electrical resistance imaging techniques for the visualization of two-phase flow fields. Two algorithms, the so-called the mesh grouping and the boundary estimation, are described for potential applications of electrical resistance tomography (ERT) and results from extensive numerical simulations are also presented. In the electrical resistance imaging for two-phase flows, numerical meshes fairly belonging to each phase can be grouped to improve the reconstruction performance. In many cases, the detection of phase boundary is a key subject and a mathematical model to estimate phase boundary can be formulated in a different manner. Our results indicated that the mesh grouping algorithm is effective to enhance computational performance and image quality, and boundary estimation algorithm to determine the phase boundary directly.

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Torque Estimation of Switched Reluctance Motor using Energy Conversion Method (에너지 변환법에 의한 스위치드 릴럭턴스 모터의 토오크 추정)

  • Kim, Youn-Hyun;Kim, Sol;Choi, Jae-Hak;Lee, Ju
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.8
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    • pp.374-383
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    • 2001
  • This paper presents the torque estimation scheme by Energy Conversion Method (ECM) that can be applied to the torque control of switched reluctance motor. There are two types of torque estimation method by ECM. One is the method using mechanical output energy and another is that using co-energy. When the torque is estimated by ECM, the estimated flux linkage can be obtained by voltage equation and Luenberger observer. By comparing the torque estimated by ECM with that be FEM, we verify the feasibility of the proposed torque estimation by ECM.

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A Study on the Validation Methodology of Network Analysis Applications in Energy Management Systems (계통운영시스템 계통해석 프로그램 검증 방안에 관한 연구)

  • Cho, Yoon-Sung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.10
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    • pp.27-36
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    • 2014
  • Network analysis applications in energy management systems play a key role in the economic and reliable operation of power systems. In order to provide operators with useful network information, the accurate results of topology processing, state estimation, power flow, and contingency analysis must be simulated. This paper proposes a validation methodology of network analysis applications in energy management systems. The energy management systems was checked to ensure that it meets the originally specified functions based on the proposed methodology. In addition, the performance of state estimation is evaluated with the reference of the proposed methodology. The proposed methodology is being conducted by energy management systems and the Korean power systems have been utilized for the test systems.

Developement of Lighting Energy Estimation Nomograph by using Daylight (자연채광 이용에 따른 조명에너지 평가용 노모그래프의 개발에 관한 연구)

  • 정유근;김정태
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.28-34
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    • 1990
  • Lighting is one of the largest energy, integrated lighting system with daylight and artificial lighting has been suggested. In such system, perimeter zone can be illuminated by daylighting and the deep area of room by artificial lighting. So, the study is to develope estimation nomograph of lighting energy by turnning-off depth and lighting control systems during daytime. For the purpose, energy nomograph has been developed to apply to side-lit office guilding and the use and limitation of the nomograph has been discussed.

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Electrochemical Analysis and SOC Estimation Techniques by Using Extended Kalman Filter of the Non-aqueous Li-air Battery (비수계 리튬에어 배터리의 전기화학적 분석 및 확장 칼만 필터를 이용한 SOC 추정기법)

  • Yoon, Chang-O;Lee, Pyeong-Yeon;Kim, Jong-Hoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.2
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    • pp.106-111
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    • 2018
  • In this work, we propose techniques for estimating the SOC of Li-air battery. First, we describe and explain the operation principle of the Li-air battery. Energy density of the Li-air battery was compared with that of the Li-ion battery. The capacity and impedance value of the fully discharged voltage is analyzed, and the OCV value for SOC estimation is measured through the electrochemical characterization of the Li-air battery. Estimation value is obtained by SOC modeling through extended Kaman filter and is compared with the measurement value from the Coulomb counting method. Moreover, the performance of SOC estimation circuit is evaluated.

Smart Air Condition Load Forecasting based on Thermal Dynamic Model and Finite Memory Estimation for Peak-energy Distribution

  • Choi, Hyun Duck;Lee, Soon Woo;Pae, Dong Sung;You, Sung Hyun;Lim, Myo Taeg
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.559-567
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    • 2018
  • In this paper, we propose a new load forecasting method for smart air conditioning (A/C) based on the modified thermodynamics of indoor temperature and the unbiased finite memory estimator (UFME). Based on modified first-order thermodynamics, the dynamic behavior of indoor temperature can be described by the time-domain state-space model, and an accurate estimate of indoor temperature can be achieved by the proposed UFME. In addition, a reliable A/C load forecast can be obtained using the proposed method. Our study involves the experimental validation of the proposed A/C load forecasting method and communication construction between DR server and HEMS in a test bed. Through experimental data sets, the effectiveness of the proposed estimation method is validated.

Comparative Analysis of SOC Estimation using EECM and NST in Rechargeable LiCoO2/LiFePO4/LiNiMnCoO2 Cells

  • Lee, Hyun-jun;Park, Joung-hu;Kim, Jonghoon
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1664-1673
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    • 2016
  • Lithium rechargeable cells are used in many industrial applications, because they have high energy density and high power density. For an effective use of these lithium cells, it is essential to build a reliable battery management system (BMS). Therefore, the state of charge (SOC) estimation is one of the most important techniques used in the BMS. An appropriate modeling of the battery characteristics and an accurate algorithm to correct the modeling errors in accordance with the simplified model are required for practical SOC estimation. In order to implement these issues, this approach presents the comparative analysis of the SOC estimation performance using equivalent electrical circuit modeling (EECM) and noise suppression technique (NST) in three representative $LiCoO_2/LiFePO_4/LiNiMnCoO_2$ cells extensively applied in electric vehicles (EVs), hybrid electric vehicles (HEVs) and energy storage system (ESS) applications. Depending on the difference between some EECMs according to the number of RC-ladders and NST, the SOC estimation performances based on the extended Kalman filter (EKF) algorithm are compared. Additionally, in order to increase the accuracy of the EECM of the $LiFePO_4$ cell, a minor loop trajectory for proper OCV parameterization is applied to the SOC estimation for the comparison of the performances among the compared to SOC estimation performance.

Frequency/Amplitude Separation Algorithm Using the Higher Order Differential Energy Operator and Its Application (고차의 미분에너지함수를 이용한 주파수 및 진폭성분 추출 알고리즘과 응용)

  • Iem, Byeong-Gwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.8
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    • pp.1498-1502
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    • 2007
  • There have been many different definitions of energy functions as the second statistics of a signal. In this paper, using the higher order differential energy function, we propose an algorithm separating the amplitude and frequency components in a discrete sinusoidal signal. The proposed amplitude and frequency estimation methods have less computational requirement than the existing methods. It also shows large computational advantage over the root mean square (RMS) calculation of a signal. The proposed methods can be used in the detection of abnormal events in signals on the power line. Computer simulations show that proposed frequency estimation method can detect the presence of voltage increase or decrease for a short period of time. Also, the proposed estimation methods have been compared with existing methods in terms of estimation error variance.