Results 241 to 250 of about 166,111,240 (297)
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Transformer Tap Setting Observability in State Estimation
IEEE Transactions on Power Systems, 2004In conventional state estimation, transformer tap settings are treated as fixed network parameters. This may reduce the accuracy of state estimation algorithm, when a tap measurement is in error or an unmeasured tap is unknown. This paper presents a numerical observability analysis algorithm for a state estimation model which treats transformer tap ...
G.N. Korres +2 more
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Observability analysis and estimation of transformer tap settings.
2003 IEEE Bologna Power Tech Conference Proceedings,, 2004This paper presents a numerical algorithm for observability analysis in a state estimation model which treats transformer tap settings as state variables and provides for turns ratio and phase-shift angle measurements. The proposed model is (transformed to a conventional node frame of reference formulation, by introducing two fictitious buses and ...
P.J. Katsikas +2 more
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Transformer Tap Setting in Optimal Load Flow
IEEE Power Engineering Review, 1985A new method of transformer ratio control in optimal load flow is presented. The transformer taps and the phase shift angles can be controlled by a quite general criterion function. The method established is valid both for two-and three-winding transformers.
N. Flatabo, J.A. Foosnas, T.-o. Berntsen
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Use of Tap Water and Disinfection Practices in Outpatient Settings: A Survey of Otolaryngologists
Archives of Otolaryngology - Head and Neck Surgery, 1991A survey of otolaryngologists belonging to the American Academy of Otolaryngology-Head and Neck Surgery was conducted to estimate the frequency of tap water use during otologic examinations and to assess methods used for disinfection of otologic instruments in outpatient settings. Questionnaires were returned by 516 persons residing in 49 states.
P W, Lowry, W R, Jarvis
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Optimization of fixed tap transformer setting in bulk electric systems
IEEE Transactions on Power Systems, 1991A novel technique was developed to determine fixed tap transformer settings that are optimal for several load patterns representing, for example, winter peak, summer peak, and off-peak loading patterns. The solution algorithm is based on the Newton approach and employs a recently developed technique to identify binding inequality constraints. A special
W. Kellerman +3 more
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Substation-oriented PMU placement considering transformer tap settings
2018 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2018The most crucial functions of modern power systems are monitoring and control. These tasks can be efficiently accomplished using synchronized phasor measurement units (PMUs) which are extremely accurate devices installed at substations providing measurements of the voltage phasor at the installation bus and the current phasors in the branches ...
Nikolaos M. Manousakis, George N. Korres
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Observability and estimation of transformer tap setting with minimal PMU placement
2008 IEEE Power and Energy Society General Meeting - Conversion and Delivery of Electrical Energy in the 21st Century, 2008One of the most important applications of phasor measurement units (PMUs) is power system state estimation. Some models have been proposed for including phasor measurements in the state estimation. But, all of these models have treated transformer tap settings (voltage transformer turns ratio and phase-shift transformer angle) as fixed parameters of ...
M. Shiroie, S. H. Hosseini
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State estimation of voltage and phase-shift transformer tap settings
IEEE Transactions on Power Systems, 1992A transformer tap estimation technique is presented that overcomes earlier limitations because of a direct algorithmic approach. The procedure provides for turn ratio and phase angle measurements, and treats each transformer tap setting as an independent state variable.
P.A. Teixeira +4 more
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Optimal tap settings for voltage regulation transformers in distribution networks
2013 North American Power Symposium (NAPS), 2013In this paper, we propose a method to optimally set the taps of voltage regulation transformers in distribution networks. Specifically, we cast the problem of optimally choosing the tap settings as a rank-constrained semidefinite program (SDP) with the transformer tap positions removed from the network's admittance matrix and replaced by additional ...
Brett A. Robbins +2 more
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