• 제목/요약/키워드: Optimal Measurement

검색결과 1,242건 처리시간 0.029초

전력시스템 고조파 상태 추정에서 면역 알고리즘 적용 (Application of Immune Algorithm for Harmonic State Estimation)

  • 왕용필;박인표;정형환
    • 대한전기학회논문지:전력기술부문A
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    • 제53권12호
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    • pp.645-654
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    • 2004
  • The design of a measurement system to perform Harmonic State Estimation(HSE) is a very complex problem. In particular, the number of available harmonic analysis measurement instruments is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents an optimal algorithm of HSE which is based on an optimal placement of measurement points using Immune Algorithm (IAs). This IA-HSE has been applied to power system for the validation of an optimal algorithm of HSE. The study results have indicated an economical and effective method for optimal placement of measurement points using Immune Algorithm (IAs) in the HSE.

페이저 측정 시스템의 측정기 최적배치 (Meter Optimal Placement in Measurement System with Phasor Measurement Unit)

  • 김재훈;조기선;김회철;신중린
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1195-1198
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    • 1999
  • This paper presents optimal placement of minimal set of phasor measurement units(PMU's) and observability of measurement system with PMU. By using the incidence matrix symbolic method which directly assigns measurement and pseudo-measurement to incidence matrix, it is much simpler and easier to analyze observability. The optimal PMU set is found through the simulated-annealing(SA) and the direct combinational method. The cooling schedule parameter which is suitable to the property of problem to solve is specified and optimal placement is proven by presented direct combinational method. Search spaces are limited within reasonable feasible solution region to reduce a unnecessary one in the SA implementation based on global search. The proposed method presents to save CPU time and estimate state vectors based on optimal PMU set.

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전력시스템 고조파 상태 추정에서 PSO 적용 (Application of Particle Swarm Optimization for Harmonic State Estimation)

  • 왕용필;정종원;김경훈;안병철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.529-530
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    • 2007
  • The design of a measurement system to perform Harmonic State Estimation(HSE) is a very complex problem. In particular, the number of available harmonic analysis measurement instruments is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents an optimal algorithm of HSE which is based on an optimal placement of measurement points using PSO. This PSO-HSE has been applied to power system for the validation of an optimal algorithm of HSE. The study results have indicated an economical and effective method for optimal placement of measurement points using PSO in the HSE.

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IA를 이용한 전력시스템 고조파 상태 추정 최적 알고리즘 (An Optimal Algorithm of Harmonic State Estimation using Immune Algorithm on Power System)

  • 박인표;왕용필;정형환;박희철;안병철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 A
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    • pp.92-94
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    • 2003
  • The design of a measurement system to perform Harmonic State Estimation(HSE) is a very complex problem. In particular, the number of available harmonic instruments (Continuous Harmonic Analysis in Real Time : CHART) is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents an optimal algorithm of HSE which is based on an optimal placement of measurement points using Immune Algorithm (IAs). This HSE has been applied to power system for the validation of an optimal algorithm of HSE. The study results have indicated an economical and effective method for optimal placement of measurement points using IAs in the HSE.

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전력시스템 고조파 상태 춘정에서 GA를 미용한 최적 측정위치 선정 (Optimal Placement of Measurement Using GAs in Harmonic State Estimation of Power System)

  • 정형환;왕용필;박희철;안병철
    • 대한전기학회논문지:전력기술부문A
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    • 제52권8호
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    • pp.471-480
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    • 2003
  • The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. Among the reasons for its complexity are the system size, conflicting requirements of estimator accuracy, reliability in the presence of transducer noise and data communication failures, adaptability to change in the network topology and cost minimization. In particular, the number of harmonic instruments available is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs) which is widely used in areas such as: optimization of the objective function, learning of neural networks, tuning of fuzzy membership functions, machine learning, system identification and control. This HSE has been applied to the Simulation Test Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using Genetic Algorithms (GAs) in the Harmonic State Estimation (HSE).

반추동물 신증의 조기진단을 위한 뇨효소 측정법 1. 효소활성도 측정을 위한 적합한 조건과 정상범위에 관하여 (Measurement of Urine Enzymes for the Early Diagnosis of Nephrosis in Ruminants 1. Optimal Conditions for Measurement of Enzyme Activities and Normal Ranges)

  • 이창우;이경갑
    • 한국임상수의학회지
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    • 제6권2호
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    • pp.291-305
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    • 1989
  • Present experiment was performed to establish the optimal reaction conditions for measurement of urinary gamma-glutamyltranspeptidase(${\gamma}$-GTP), N-acetyl-${\beta}$-D-glucosaminidase (AGS) and alanine aminopeptidase(AAP) activities in bovine and to investigate in vitro stability of the enzymes, within-run imprecision of the methods, and normal ranges. 1. The optimal wavelength for measurement of ${\gamma}$-GTP activity was 545nm. 2. The optimal pH of Tris-HCI buffer containing glycylglycine for measurement of urinary ${\gamma}$-GTP activity was 7.6~7.8(37$^{\circ}C$). 3. Coefficient of variance for within-run imprecision of urinary ${\gamma}$-GTP activity ranged from 4.8 to 7.2% and there was no significant difference among replications, 4. The optimal wavelength for measurement of urinary AGS activity was 405nm. 5. The optimal pH of citrate buffer for measurement urinary of AGS activity was 4.0(37$^{\circ}C$). 6. Coefficient of variance for within-run imprecision of urinary AGS activity ranged from 3.9 to 6.1% and there was no significant difference among replications. 7. The optimal wavelength for measurement of urinary AAP activity was 400nm. 8. The optimal pH of phosphate buffer for measurement of urinary AAP was 7.8. 9. Coefficient of variance for within-run imprecision of urinary AAP activity ranged from 2.5 to 4.8% and there was no significant difference among replications. 10. ${\gamma}$-GTP and AGS activities were increased significantly by gel-filtration. 11. Turbidity interfered with measurement of urinary AAP activity in bovine unless the specimen was gel-filterated. 12. Preservation of the specimen at 5$^{\circ}C$ or -20$^{\circ}C$ did not affect the AGS activity at least for 7 days after collection. 13. Preservation of the specimen at 5$^{\circ}C$ or 20$^{\circ}C$ did not affect the ${\gamma}$-GTP and AAP activities statistically, but some individual specimens revealed fluctuation during preservation. 14. ${\gamma}$-GTP, AGS and AAP activities revealed fluctuation by the tine of the day when the specimen was collected. 15. The normal ranges of urinary ${\gamma}$ -GTP, AGS and AAP activities were 6.60${\pm}$3.26(2.36-14.50), 1.31 ${\pm}$ 0.81(0.33-3.78), and 1.73 ${\pm}$ 0.55(0.77-3.03)U/l. respectively.

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Utilization of Light Microscopy and FFT for MFA Measurement from Unstained Sections of Red Pine (Pinus Densiflora)

  • Kwon, Ohkyung;Lee, Mi-Rim;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
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    • 제41권5호
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    • pp.399-405
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    • 2013
  • This study demonstrates the utilization of light microscopy and Fast Fourier Transform-Peak Finding (FPF) method for microfibril angle (MFA) measurement from unstained sections of red pine (Pinus densiflora). To obtain an image with optimal contrast and resolution for MFA measurement, effects of numerical aperture (NA) of condenser lens and color filters were investigated. About 60% of NA of the maximum condenser NA produced an image with optimal contrast, but a color filter with short wavelength range (DAPI) created images with improved resolution. Manual angle measurement and the FPF method were applied to the image with optimal contrast for MFA measurement. The experimental results from the FPF method were considered to be more repeatable and less subjective than those from the manual angle measurement.

고조파 상태 추정에 있어서 유전 알고리즘을 이용한 최적 측정위치 선정 (Optimal Placement of Measurements using Genetic Algorithms for Harmonic State Estimation)

  • 정형환;왕용필;이정필;박희철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.298-300
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    • 2002
  • The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. In particular, the number of available harmonic instruments(Continuous Harmonic Analysis in Real Time : CHART) is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs). This HSE has been applied to the New Zealand AC Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using GAs in the HSE.

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A Multi-objective Placement of Phasor Measurement Units Considering Observability and Measurement Redundancy using Firefly Algorithm

  • Arul jeyaraj, K.;Rajasekaran, V.;Nandha kumar, S.K.;Chandrasekaran, K.
    • Journal of Electrical Engineering and Technology
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    • 제10권2호
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    • pp.474-486
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    • 2015
  • This paper proposes a multi-objective optimal placement method of Phasor Measurement Units (PMUs) in large electric transmission systems. It is proposed for minimizing the number of PMUs for complete system observability and maximizing measurement redundancy of the buses, simultaneously. The measurement redundancy of the bus indicates that number of times a bus is able to monitor more than once by PMUs set. A high level of measurement redundancy can maximize the system observability and it is required for a reliable power system state estimation. Therefore, simultaneous optimizations of the two conflicting objectives are performed using a binary coded firefly algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is added to the main model. The practical measurement limitation of PMUs is also considered. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems and a real and large- scale Polish 2383 bus system. The valuable approach of firefly algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing its performance with earlier works.

Optimal Measurement Placement for Static Harmonic State Estimation in the Power Systems based on Genetic Algorithm

  • Dehkordl, Behzad Mirzaeian;Fesharaki, Fariborz Haghighatdar;Kiyournarsi, Arash
    • Journal of Electrical Engineering and Technology
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    • 제4권2호
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    • pp.175-184
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    • 2009
  • In this paper, a method for optimal measurement placement in the problem of static harmonic state estimation in power systems is proposed. At first, for achieving to a suitable method by considering the precision factor of the estimation, a procedure based on Genetic Algorithm (GA) for optimal placement is suggested. Optimal placement by regarding the precision factor has an evident solution, and the proposed method is successful in achieving the mentioned solution. But, the previous applied method, which is called the Sequential Elimination (SE) algorithm, can not achieve to the evident solution of the mentioned problem. Finally, considering both precision and economic factors together in solving the optimal placement problem, a practical method based on GA is proposed. The simulation results are shown an improvement in the precision of the estimation by using the proposed method.