Overview of tapping methods from high voltage transmission lines
- Authors: Nicolae, Dan-Valentin , Jimoh, A. A. , Van Rensburg, J. F. J. , Case, M. J.
- Date: 2005
- Subjects: Tapping tools , High-voltage accelerators
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22415 , uj:16200 , ISBN:9536037432 , Citation: Nicolae, D.V., Siti, M.W. & Jimoh, A.A. 2005. Overview of tapping methods from high voltage transmission lines. EDPE 2005 Conference, Dubrovnik, Croatia 26-29 September 2005.
- Description: Abstract: This paper takes an overview of various electric energy tapping methods from high voltage transmission lines.Some of these have been studied and implemented previously, some of them are in advance stage of implementation and other new methods have just been started and they are at the initial stage of modeling and simulation. this paper briefly covers the tapping methods for ac transmission lines including two new methods that are at the final stage of research. Dc transmission presents a more challenging situation, but this paper manages to present a few new methods for energy tapping.
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Performance analysis of a three-phase induction motor with capacitance injection
- Authors: Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2006
- Subjects: Three-phase machines , Induction motors , Reactive compensation , Power factor correction
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22554 , uj:16209 , Citation: Jimoh, A.A. & Nicolae, D.V. 2006. Performance analysis of a three-phase induction motor with capacitance injection. OPTIM, 10th International Conference on Optimization of Electrical and Electronic Equipments, 17-20 May, 2006, Brasov, Romania.
- Description: Abstract: In this paper a static switched capacitor with an auxiliary three-phase stator winding, which is only magnetically coupled to the stator main winding, is explored for improving the starting and operating power factor of a three-phase induction motor. The scheme improves the power factor of the motor without compromising significantly on other performances. Important advantages of the scheme include preventing harmonics in the line current, and eliminating regeneration possibility as well as preventing high inrush currents at starting.
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Performance analysis of capacitance compensated dual stator winding synchronous reluctance machine
- Authors: Ogunjuyigbe, A. S. O. , Jimoh, A. A. , Nicolae, Dan-Valentin , Obe, E. S.
- Date: 2010
- Subjects: Capacitance meters , Synchronous machinery , Torque
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18633 , uj:16024 , ISSN:1827-6660 , Citation: Ogunjuyigbe, A.S.O. et al. 2010. Performance analysis of capacitance compensated dual stator winding synchronous reluctance machine. International Review of Electrical Engineering,5(2), April 2010:437-446
- Description: Abstract: Synchronous reluctance machine with simple salient rotor are known to have poor power factor because they have a low effective reactance ratio. This paper used a 3 phase auxiliary winding and balanced capacitance compensation to ifluence the effective reactance ratio of a synchronous reluctance machine with simple salient rotor structure, such that its power factor and torque/ampere performance is improved. A mathematical model and dq equivalent circuit suitable for dynamic and steady state analysis was developed and used to study the synchronous operation of this machine.Analytical as well as experimental results for a 4-pole, 36 slots simple salient rotor reluctance machine showed that the effective reactance ration increased with the capacitance size, and the machine operated at a maximum power factor of 0.969 without altering the geometry of the rotor. the torque per ampere of the machine also improved with the size of capacitor attached to the auxilary winding.
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Phase load balancing in the secondary distribution network using fuzzy logic
- Authors: Siti, M. W. , Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Circuit breakers , Transmission
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/20257 , uj:16084 , ISBN:078038606x , Citation: Siti, M.W., Jimoh, A.A. & Nicolae, D.-V. 2007. Phase load balancing in the secondary distribution network using fuzzy logic. IEEE AFRICON’07, Windhoek, Namibia, 26-28 September, 2007:1-7. DOI:10.1109/AFRCON.2007.4401569
- Description: Abstract: The electrical network system is to ensure that an adequate supply is available to meet the estimated load of the consumers in both the near and more distant future. This must of course, be done for minimum possible cost consistent with satisfactory reliability and quality of the supply. In order to avoid excessive voltage drop and minimize loss, it may be economical to install apparatus to balance or partially balance the loads. It is believed that the technology to achieve an automatic load balancing lends itself readily for the implementation of different types of algorithms for automatically rearranging the connection of consumers on the low voltage and of a feeder for optimal performance. In this paper the fuzzy logic is been implemented to balance the load in the secondary part of the transformer
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Synchronous reluctance machine with controlled capacitance injection
- Authors: Ogunjuyigbe, A. S. O. , Jimoh, A. A. , Nicolae, Dan-Valentin , Agee, J. T.
- Date: 2008
- Subjects: Capacitators , Switched capacitator circuits
- Language: English
- Type: Conference procedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/382760 , http://hdl.handle.net/10210/18737 , uj:16038 , Citation: Ogunjuyigbe, A.S.O. et al. 2008. Synchronous reluctance machine with controlled capacitance injection. OPTIM'08, 22-24 May, Brasov, Romania. DOI: 10.1109/OPTIM.2008.4602384
- Description: Abstract This paper describes a detailed analysis, verified by practical experimental results, of a synchronous reluctance machine with two similar stator windings and capacitance injection using a static switch. The steady state equivalent circuit is developed and used to investigate leading capacitance injection into the machine via a balanced three phase auxiliary winding that is only magnetically coupled to the main winding. The scheme was found to improve the torque and power factor performance of the machine as well as reduce harmonics in the line current. Two switching topologies were utilized for the static control in this arrangement, and both were found to present good and comparable results. Experimental results corroborate the simulations.
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Synchronous reluctance machine with magnetically-coupled, double three-phase windings
- Authors: Ogunjuyigbe, A. S. O. , Obe, E. S. , Nicolae, Dan-Valentin , Jimoh, A. A.
- Date: 2009
- Subjects: Electromagnetism , Electric transformers
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22421 , uj:16198 , Citation: Ogunjuyigbe, A.S.O, et al. 2009. Synchronous reluctance machine with magnetically-coupled, double three-phase windings. Proceedings of the Electromotion Joint Symposium, 1-3 September 2009, Lille, France.
- Description: Abstract: Please refer to full text to view abstract Please refer to full text to view abstract
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Test results on synchronous reluctance machine with auxilliary winding for leading reactive power injection
- Authors: Ogunjuyigbe, A. S. O. , Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2008
- Subjects: Synchronous machinery , Performance standards , Capacitance injection
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/16468 , uj:15776 , Citation: Ogunjuyigbe, A.S.O., Jimoh, A.A. & Nicolae, D.V. 2008. Test results on synchronous reluctance machine with auxilliary winding for leading reactive power injection. Proceedings of the second IASTED Africa Conference Power and Energy Systems (AfricaPES 2008)September 8-10, 2008, Gaborone, Botswana
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The use of multi agent system for monitoring and control of the smelting process in the mining metallurgical sector
- Authors: Siti, M. , Jordaan, J. , Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2005
- Subjects: Metallurgy , Power energy , Voltage detectors
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22052 , uj:16160 , ISBN: 0780393279 , Citation: Siti, M. et al. 2005. The use of multi agent system for monitoring and control of the smelting process in the mining metallurgical sector. IEEE PES 2005 Inaugural Conference and Exposition in Africa, South Africa, 11-15 July, 2005:326-331.
- Description: Abstract: This paper is focusing on the development of intelligent agent technology and application of that technology to the mining and metallurgical sector.We have shown how networks of communicating and cooperating intelligent software agents can be used to implement complex distributed systems. in the mining and metallurgical industries there are processes which cannot tolerate interruption, such as some sequential line chemical processes.
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The use of support vector machine for phase balancing in the distribution feeder
- Authors: Siti, M. W. , Jimoh, A. A. , Jordaan, J. A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Electric power transmission , Distribution channels
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21374 , uj:16146 , ISSN: 0302-9743 , Citation: Siti, M.W. et al. 2007. The use of support vector machine for phase balancing in the distribution feeder. ICONIP 2007, Neural Information Processing Lecture Notes in Computer Science, 4985:721-729 , DOI:10.1007/978354069162475
- Description: Abstract: Phase voltage and current unbalances in power system distribution networks are major factors leading to extra losses, communication interference, equipment overloading, and malfunctioning of the protective relay, which consequently results in service quality and operation efficiency being reduced. As a better alternative to the traditional practices of manual trial and error, and the contemporary solution technique of network reconfiguration or load rearrangement, this paper investigates and proposes a novel method that is based on the use of the historical data and artificial intelligence for eliminating or minimizing phase unbalance problems. The proposed method is based on support vector machine
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Torque ripple analysis of three-phase induction machines with non-uniform coil groups distribution
- Authors: Muteba, M. , Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2013
- Subjects: Electronic motors , Electrostatic induction , Electric machinery induction
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18069 , uj:15956 , ISBN: 978-1-4673-4974-1 , Citation: Muteba, M., Jimoh, A.A., & Nicolae, D.V. 2013. Torque ripple of three-phase induction machines with non-uniform coil groups distribution. IEEE International Electric Machines and Drives Conference (IEMDC2013), 12-15 May 2013, Chicago, USA. DOI: 10.1109/IEMDC.2013.6556313
- Description: Abstract Please refer to full text to view abstract
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Torque ripple reduction in five-phase induction machines using mixed winding configurations
- Authors: Muteba, M. , Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2012
- Subjects: Torque ripple , Winding combinations , Induction machines
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17823 , uj:15929 , ISBN:9781467301428 , Citation: Muteba, M.,Jimoh, A.A. & Nicolae, D.V. 2012. Torque ripple reduction in five-phase induction machines using mixed winding configurations. Electrical Machines(ICEM), 2012 xxth International conference:512-518.DOI:10.1109/ICEM!Mach.2012.6349918
- Description: Abstact: In this paper, the authors take a particular look at the effects of combination of different stator winding configurations in a 40 stator slots, 2-pole, and five-phase induction machine. They show, through computer simulation, that the combination of double and triple layer with 19/20 coil pitch reduced the torque ripple from 19.1%, for the conventional single layer full pitch, and from 10.6 %, for the conventional double layer with 19/20 coil pitch having the same rating, down to 8.7 % while maintaining the torque average. The same has to be said for the double combination which is the combination of double and triple layer combined with slot shift and coil side shift in one slot having 9/10 coil pitch. This double combination reduces tremendously the torque ripple from 28.8 %, for a conventional double layer 9/10 coil pitch, down to 10.2 % and still maintained the torque average. Some other winding combinations reduce both average and torque ripple
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