A study of improving the power factor of a three-phase induction motor using a static switched capacitor
- Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Jimoh, Adisa 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/10210/22367 , uj:16193 , ISSN: 1-4244-0121-6 , Citation: Jimoh, A.A. & Nicolae, D.V. 2006. A study of improving the power factor of a three-phase induction motor using a static switched capacitor. EPE-PEMC, 12th International Power Electronics and Motion Control, September, 2006, Portorož, Slovenia.
- 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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- Authors: Jimoh, Adisa 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/10210/22367 , uj:16193 , ISSN: 1-4244-0121-6 , Citation: Jimoh, A.A. & Nicolae, D.V. 2006. A study of improving the power factor of a three-phase induction motor using a static switched capacitor. EPE-PEMC, 12th International Power Electronics and Motion Control, September, 2006, Portorož, Slovenia.
- 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.
- Full Text:
Active power control for capacitive divider tapping method
- Nicolae, Dan-Valentin, Jimoh, Adisa A., Britten, Anton C.
- Authors: Nicolae, Dan-Valentin , Jimoh, Adisa A. , Britten, Anton C.
- Date: 2006
- Subjects: Power systems , Captive divider systems , Tapping electric power
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22404 , uj:16197 , ISSN: 1-4244-0121-6 , Citation: Nicolae, D.V., Jimoh, A.A. & Britten, A.C. 2006. Active power control for capacitive divider tapping method. EPE-PEMC, 12th International Power Electronics and Motion Control, 30 August-1 September, 2006, Portorož, Slovenia.
- Description: Abstract: Capacitive divider systems for tapping electric power from high voltage transmission lines are known to exhibit certain detrimental problems of stability, sub-resonance harmonic oscillations, and ferroresonance when coupled with non-linear loads. On the other hand, they can improve reactive power flow, power factor and contribute to improved harmonic filtration of the larger power system. This paper, therefore, proposes a controlled power flow conditioner as an essential integral component of a capacitive divider system to control power transfer between the high voltage transmission line, capacitive divider system, and the load. The ultimate objective of this conditioner is to mitigate or minimize the attendant problems associated with coupling the system to the load, and optimize the derivable benefits to the larger network.
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- Authors: Nicolae, Dan-Valentin , Jimoh, Adisa A. , Britten, Anton C.
- Date: 2006
- Subjects: Power systems , Captive divider systems , Tapping electric power
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22404 , uj:16197 , ISSN: 1-4244-0121-6 , Citation: Nicolae, D.V., Jimoh, A.A. & Britten, A.C. 2006. Active power control for capacitive divider tapping method. EPE-PEMC, 12th International Power Electronics and Motion Control, 30 August-1 September, 2006, Portorož, Slovenia.
- Description: Abstract: Capacitive divider systems for tapping electric power from high voltage transmission lines are known to exhibit certain detrimental problems of stability, sub-resonance harmonic oscillations, and ferroresonance when coupled with non-linear loads. On the other hand, they can improve reactive power flow, power factor and contribute to improved harmonic filtration of the larger power system. This paper, therefore, proposes a controlled power flow conditioner as an essential integral component of a capacitive divider system to control power transfer between the high voltage transmission line, capacitive divider system, and the load. The ultimate objective of this conditioner is to mitigate or minimize the attendant problems associated with coupling the system to the load, and optimize the derivable benefits to the larger network.
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Alternative method for the identification of critical nodes leading to voltage instability in a power system
- Adebayo, Isaiah G., Jimoh, Adisa A., Yusuff, Adedayo A., Sun, Yanxia
- Authors: Adebayo, Isaiah G. , Jimoh, Adisa A. , Yusuff, Adedayo A. , Sun, Yanxia
- Date: 2018
- Subjects: Graph theory , Network topology , Power flow
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/274893 , uj:29349 , Citation: Adebayo, I.G. et al. 2018. Alternative method for the identification of critical nodes leading to voltage instability in a power system.
- Description: Abstract: Introduction of new operation enhancement technologies plus increasing application of power electronics coupled with the continuous increase in load demand has increased the risk of power networks to voltage instability and susceptibility to voltage collapse. This frequent occurrence of voltage collapse in modern power system has been a growing concern to power system utilities. This paper proposes alternative techniques for the identification of critical nodes that are liable to voltage instability in a power system. The first method is based on the critical mode corresponding to the smallest eigenvalues, while the second technique is based on the centrality measure to identify the influential node of the networks. The eigenvector centrality measure is formulated from the response matrices of both the load and generator nodes of the networks. The effectiveness of the suggested approaches is tested using the IEEE 30 bus and the Southern Indian 10 bus power networks. The results are compared to the techniques based on the traditional power flow. The whole procedure of the results involved in the identification of critical nodes through the proposed methods is totally non-iterative and thereby save time and require less computational burden.
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- Authors: Adebayo, Isaiah G. , Jimoh, Adisa A. , Yusuff, Adedayo A. , Sun, Yanxia
- Date: 2018
- Subjects: Graph theory , Network topology , Power flow
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/274893 , uj:29349 , Citation: Adebayo, I.G. et al. 2018. Alternative method for the identification of critical nodes leading to voltage instability in a power system.
- Description: Abstract: Introduction of new operation enhancement technologies plus increasing application of power electronics coupled with the continuous increase in load demand has increased the risk of power networks to voltage instability and susceptibility to voltage collapse. This frequent occurrence of voltage collapse in modern power system has been a growing concern to power system utilities. This paper proposes alternative techniques for the identification of critical nodes that are liable to voltage instability in a power system. The first method is based on the critical mode corresponding to the smallest eigenvalues, while the second technique is based on the centrality measure to identify the influential node of the networks. The eigenvector centrality measure is formulated from the response matrices of both the load and generator nodes of the networks. The effectiveness of the suggested approaches is tested using the IEEE 30 bus and the Southern Indian 10 bus power networks. The results are compared to the techniques based on the traditional power flow. The whole procedure of the results involved in the identification of critical nodes through the proposed methods is totally non-iterative and thereby save time and require less computational burden.
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Analytical design and analysis of line-start permanent magnet synchronous motors
- Stoia, Dan, Cernat, Mihai, Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Stoia, Dan , Cernat, Mihai , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2009
- Subjects: Electric motors, synchronous
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21553 , uj:16149 , ISBN: 978-1-4244-3919-5 , Citation: Stoia, D. et al. 2009. Analytical design and analysis of line-start permanent magnet synchronous motors. IEEE-Africon, 23-25 September, 2009, Kenya. DOI: 10.1109/AFRCON.2009.5308177
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Stoia, Dan , Cernat, Mihai , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2009
- Subjects: Electric motors, synchronous
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21553 , uj:16149 , ISBN: 978-1-4244-3919-5 , Citation: Stoia, D. et al. 2009. Analytical design and analysis of line-start permanent magnet synchronous motors. IEEE-Africon, 23-25 September, 2009, Kenya. DOI: 10.1109/AFRCON.2009.5308177
- Description: Please refer to full text to view abstract
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Dynamic and steady state behavior of a synchronous reluctance machine with leading reactive power through an auxiliary winding
- Ogunjuyigbe, Ayodeji Samson, Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Ogunjuyigbe, Ayodeji Samson , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2008
- Subjects: Electric machinery , Electric transformers
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18445 , uj:16000 , Citation: Ongunjuyigbe, A.S.O, Jimoh, A.A. & Nicolae, D.A. 2008. Dynamic and steady state behavior of a synchronous reluctance machine with leading reactive power through an auxiliary winding. Proceedings of the 9th International Conference on Modeling and Simulation of Electric Machines, Converters and Systems ELECTRIMACS, June 2008.
- Description: Abstract In attempt to improve the performance of synchronous reluctance machine the structure of the machine is modified to include an additional winding on the stator and injection of capacitance. This paper examines the dynamic and steady state behaviour of the modified machine based on its mathematical model and experiments performed on a practical prototype. The experimental results corroborate the solutions of the mathematical model as obtained through simulation. The modified machine shows significant improvement in performance over the conventional one.
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- Authors: Ogunjuyigbe, Ayodeji Samson , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2008
- Subjects: Electric machinery , Electric transformers
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18445 , uj:16000 , Citation: Ongunjuyigbe, A.S.O, Jimoh, A.A. & Nicolae, D.A. 2008. Dynamic and steady state behavior of a synchronous reluctance machine with leading reactive power through an auxiliary winding. Proceedings of the 9th International Conference on Modeling and Simulation of Electric Machines, Converters and Systems ELECTRIMACS, June 2008.
- Description: Abstract In attempt to improve the performance of synchronous reluctance machine the structure of the machine is modified to include an additional winding on the stator and injection of capacitance. This paper examines the dynamic and steady state behaviour of the modified machine based on its mathematical model and experiments performed on a practical prototype. The experimental results corroborate the solutions of the mathematical model as obtained through simulation. The modified machine shows significant improvement in performance over the conventional one.
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Dynamic and steady state behaviour of a synchronous reluctance machine with leading reactive power through an auxiliary winding
- Ogunjuyigbe, Ayodeji Samson, Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Ogunjuyigbe, Ayodeji Samson , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Electric machinery , Electric transformers
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/15599 , uj:15680 , Citation: Ogunjuyigbe, A.S., Jimoh, A.A. & Nicolae, D.V. 2007.Improving synchronous reluctance machine performance by direct capacitance injection through an auxiliary winding. Proceedings of the International Conference on Electrical Machines and Systems ICEMS 2007, paper IMP-05:1055-1060.
- Description: In attempt to improve the performance of synchronous reluctance machine the structure of the machine is modified to include an additional winding on the stator and injection of capacitance. This paper examines the dynamic and steady state behaviour of the modified machine based on its mathematical model and experiments performed on a practical prototype. The experimental results corroborate the solutions of the mathematical model as obtained through simulation. The modified machine shows significant improvement in performance over the conventional one.
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- Authors: Ogunjuyigbe, Ayodeji Samson , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Electric machinery , Electric transformers
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/15599 , uj:15680 , Citation: Ogunjuyigbe, A.S., Jimoh, A.A. & Nicolae, D.V. 2007.Improving synchronous reluctance machine performance by direct capacitance injection through an auxiliary winding. Proceedings of the International Conference on Electrical Machines and Systems ICEMS 2007, paper IMP-05:1055-1060.
- Description: In attempt to improve the performance of synchronous reluctance machine the structure of the machine is modified to include an additional winding on the stator and injection of capacitance. This paper examines the dynamic and steady state behaviour of the modified machine based on its mathematical model and experiments performed on a practical prototype. The experimental results corroborate the solutions of the mathematical model as obtained through simulation. The modified machine shows significant improvement in performance over the conventional one.
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Forecasting model for energy consumption in South Africa correlated with the income
- Siti, M. W., Nicolae, Dan-Valentin, Jimoh, Adisa A.
- Authors: Siti, M. W. , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2008
- Subjects: Electric power consumption , Energy consumption
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/372690 , http://hdl.handle.net/10210/18828 , uj:16048 , Citation: Siti, M.W., Nicolae, D.V. & Jimoh, A.A. 2008. Forecasting model for energy consumption in South Africa correlated with the income. Conference proceedings of the IASTED International Conference on Power and Energy Systems, 8-10 September, Gaborone, Botswana.
- Description: Abstract This paper presents a mathematical model that forecasts the energy consumption in South Africa. The model is correlated to the income of the consumers. The study made use of the real energy consumption audit in South Africa. The mathematical model in this work is developed around the variables identified from the survey. The model can be applied to other utilities worldwide with some modifications in the influencing parameter values. The model developed was used to study the effect of certain indices; such as society, personality, and fixed contribution index on the electricity consumption. Different results obtained and presented in this work clearly show that the income is a major determinant of energy consumption.
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- Authors: Siti, M. W. , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2008
- Subjects: Electric power consumption , Energy consumption
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/372690 , http://hdl.handle.net/10210/18828 , uj:16048 , Citation: Siti, M.W., Nicolae, D.V. & Jimoh, A.A. 2008. Forecasting model for energy consumption in South Africa correlated with the income. Conference proceedings of the IASTED International Conference on Power and Energy Systems, 8-10 September, Gaborone, Botswana.
- Description: Abstract This paper presents a mathematical model that forecasts the energy consumption in South Africa. The model is correlated to the income of the consumers. The study made use of the real energy consumption audit in South Africa. The mathematical model in this work is developed around the variables identified from the survey. The model can be applied to other utilities worldwide with some modifications in the influencing parameter values. The model developed was used to study the effect of certain indices; such as society, personality, and fixed contribution index on the electricity consumption. Different results obtained and presented in this work clearly show that the income is a major determinant of energy consumption.
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Improving three-phase induction machines power factor using single phase auxiliary winding fed by an active power filter
- Muteba, Mbika C., Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Muteba, Mbika C. , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Heat recovery , Heat transfer
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/20373 , uj:16089 , ISBN:078038606x , Citation: Muteba, M.C., Jimoh, A.A. & Nicolae, D.V. 2007. Improving three-phase induction machines power factor using single phase auxiliary winding fed by an active power filter, IEEE AFRICON’07, Windhoek, Namibia, 26-28 September 2007:1-7 , DOI:10.1109/AFRCON.2007.4401570
- Description: Abstract: This paper presents a three-phase induction machine that employs a single phase auxiliary winding, which is only magnetically coupled to the stator main winding, and controlled by an active power filter. The active filter consists mainly of a two leg PWM voltage source inverter, which together with the auxiliary winding serves to supply leading reactive power to the machine. With sufficient ampere-turn capability of the auxiliary winding and an adequate control algorithm, the computer simulation results show that it is possible to obtain nearly unity power factor operation at the terminals of the main winding over a range of load conditions including rated load. The simulated power factor of this scheme is compared with the measured result for a typical practical induction motor.
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- Authors: Muteba, Mbika C. , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Heat recovery , Heat transfer
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/20373 , uj:16089 , ISBN:078038606x , Citation: Muteba, M.C., Jimoh, A.A. & Nicolae, D.V. 2007. Improving three-phase induction machines power factor using single phase auxiliary winding fed by an active power filter, IEEE AFRICON’07, Windhoek, Namibia, 26-28 September 2007:1-7 , DOI:10.1109/AFRCON.2007.4401570
- Description: Abstract: This paper presents a three-phase induction machine that employs a single phase auxiliary winding, which is only magnetically coupled to the stator main winding, and controlled by an active power filter. The active filter consists mainly of a two leg PWM voltage source inverter, which together with the auxiliary winding serves to supply leading reactive power to the machine. With sufficient ampere-turn capability of the auxiliary winding and an adequate control algorithm, the computer simulation results show that it is possible to obtain nearly unity power factor operation at the terminals of the main winding over a range of load conditions including rated load. The simulated power factor of this scheme is compared with the measured result for a typical practical induction motor.
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LV and MV distribution networks reconfiguration for minimum losses
- Siti, Willy M., Nicolae, Dan-Valentin, Jimoh, Adisa A.
- Authors: Siti, Willy M. , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2006
- Subjects: Distribution networks , Electricity supply
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22442 , uj:16202 , ISSN: 1-4244-0121-6 , Citation: Siti, W.M., Nicolae, D.V. & Jimoh, A.A. 2006. LV and MV distribution networks reconfiguration for minimum losses. EPE-PEMC, 12th International Power Electronics and Motion Control, 30 August-1 September, 2006, Portorož, Slovenia.
- Description: Abstract: The reconfiguration of the distribution network feeders can be defined as the restructuring of the feeders through the changing of the open/close states of the sectionalizing and tie switches. This creation of a new distribution network topology is normally required to improve the performance of the network, and thus sometimes the efficiency of the electricity supply. For optimum loss reduction, feeder reconfiguration is often considered as an option. This, however, requires the implementation of an appropriate switching control strategy. It would be desirable for the switching to be automatic, that is to follow the connected load situation of the feeder. The proposed optimal reconfiguration of the phase balancing using the heuristic method proves to be robust compared to neural network method, to turn ON and OFF the different switches, allowing the three phases supply of the transformer to the end-users to be balanced. This paper presents the application examples of the proposed method using the real data.
- Full Text:
- Authors: Siti, Willy M. , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2006
- Subjects: Distribution networks , Electricity supply
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/22442 , uj:16202 , ISSN: 1-4244-0121-6 , Citation: Siti, W.M., Nicolae, D.V. & Jimoh, A.A. 2006. LV and MV distribution networks reconfiguration for minimum losses. EPE-PEMC, 12th International Power Electronics and Motion Control, 30 August-1 September, 2006, Portorož, Slovenia.
- Description: Abstract: The reconfiguration of the distribution network feeders can be defined as the restructuring of the feeders through the changing of the open/close states of the sectionalizing and tie switches. This creation of a new distribution network topology is normally required to improve the performance of the network, and thus sometimes the efficiency of the electricity supply. For optimum loss reduction, feeder reconfiguration is often considered as an option. This, however, requires the implementation of an appropriate switching control strategy. It would be desirable for the switching to be automatic, that is to follow the connected load situation of the feeder. The proposed optimal reconfiguration of the phase balancing using the heuristic method proves to be robust compared to neural network method, to turn ON and OFF the different switches, allowing the three phases supply of the transformer to the end-users to be balanced. This paper presents the application examples of the proposed method using the real data.
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Operating strategies and capacitor voltace balance strategies for a cascaded "3-5-9" hybrid inverter for grid interface application
- Wanjekeche, Tom, Nicolae, Dan-Valentin, Jimoh, Adisa A.
- Authors: Wanjekeche, Tom , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2014
- Subjects: Electric power supply , Power electronics
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17500 , uj:15891 , Citation: Wanjekeche, T., Nicolae, D.V. & Jimoh, A.A. 2014. Operating strategies and capacitor voltace balance strategies for a cascaded "3-5-9" hybrid inverter for grid interface application. International journal of modelling and simulation, 34(1). DOI:10.2316/Journal.205.2014.1.205-5724-5724 , DOI:10.2316/Journal.205.2014.1.205-5724 , ISSN:0228-6203 (Print) , ISSN:1925-7082 (Online)
- Description: Abstract: The paper presents a novel phase shifted SPWM control scheme for cascading two cells to form a “3-5-9 hybrid inverter with improved harmonic suppression. Modeling of the hybrid inverter from first principle is introduced and a standard control law is derived for further analysis and development of the model. A new balance circuit for DC link voltage control is designed and tested. Combined with individual voltage control, a complete control scheme is developed. Detailed MATLAB simulation and experimental results are obtained for further validation of the adopted topology and the control scheme
- Full Text:
- Authors: Wanjekeche, Tom , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2014
- Subjects: Electric power supply , Power electronics
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17500 , uj:15891 , Citation: Wanjekeche, T., Nicolae, D.V. & Jimoh, A.A. 2014. Operating strategies and capacitor voltace balance strategies for a cascaded "3-5-9" hybrid inverter for grid interface application. International journal of modelling and simulation, 34(1). DOI:10.2316/Journal.205.2014.1.205-5724-5724 , DOI:10.2316/Journal.205.2014.1.205-5724 , ISSN:0228-6203 (Print) , ISSN:1925-7082 (Online)
- Description: Abstract: The paper presents a novel phase shifted SPWM control scheme for cascading two cells to form a “3-5-9 hybrid inverter with improved harmonic suppression. Modeling of the hybrid inverter from first principle is introduced and a standard control law is derived for further analysis and development of the model. A new balance circuit for DC link voltage control is designed and tested. Combined with individual voltage control, a complete control scheme is developed. Detailed MATLAB simulation and experimental results are obtained for further validation of the adopted topology and the control scheme
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Performance analysis of a three-phase induction motor with double-triple winding layout
- Muteba, Mbika, Jimoh, Adisa A.
- Authors: Muteba, Mbika , Jimoh, Adisa A.
- Date: 2013
- Subjects: Winding function
- Type: Article
- Identifier: http://hdl.handle.net/10210/18660 , uj:16027 , ISBN: 9781479900732 , Citation: Muteba,M., Jimoh, A.A. 2013. Performance analysis of a three-phase induction motor with double-triple winding layout. IEEE: 131-136.
- Description: Abstract: This paper presents the performance of threephase induction motor with a stator winding comprising of a combination of double and triple layer arrangements in slots, here simply referred to as double-triple stator winding layouts. The proposed layout provides a three-phase induction motor with high torque density and greater efficiency than the conventional machine with double winding layout. Field analysis technique is used to show that this winding arrangement has improved harmonic content and the machine performance is computed using Finite Element Method (FEM). Saturation is accounted for in the computation of the inductances. A 1500 W conventional three-phase induction machine with 36 stator slots is first wound as a four-pole double layer and then as a four-pole double-triple layer for the experimental study. Both windings are chorded with one slot with same number of turns per phase and use the same squirrel cage rotor.
- Full Text:
- Authors: Muteba, Mbika , Jimoh, Adisa A.
- Date: 2013
- Subjects: Winding function
- Type: Article
- Identifier: http://hdl.handle.net/10210/18660 , uj:16027 , ISBN: 9781479900732 , Citation: Muteba,M., Jimoh, A.A. 2013. Performance analysis of a three-phase induction motor with double-triple winding layout. IEEE: 131-136.
- Description: Abstract: This paper presents the performance of threephase induction motor with a stator winding comprising of a combination of double and triple layer arrangements in slots, here simply referred to as double-triple stator winding layouts. The proposed layout provides a three-phase induction motor with high torque density and greater efficiency than the conventional machine with double winding layout. Field analysis technique is used to show that this winding arrangement has improved harmonic content and the machine performance is computed using Finite Element Method (FEM). Saturation is accounted for in the computation of the inductances. A 1500 W conventional three-phase induction machine with 36 stator slots is first wound as a four-pole double layer and then as a four-pole double-triple layer for the experimental study. Both windings are chorded with one slot with same number of turns per phase and use the same squirrel cage rotor.
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Performance analysis of induction machines with unconventional winding configurations
- Muteba, Mbika, Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Muteba, Mbika , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Subjects: Induction machines , Fractional slots , Distributed performance , Unconventional windings , Torque ripple
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18322 , uj:15984 , Citation: Muteba M., Jimoh, A.A., Nicolae, D.V. Performance analysis of induction machines with unconventional winding configurations: 1-5.
- Description: Abstract: This paper presents the performance of fractional slots distributed windings (FSDW) and fractional slots concentrated windings (FSCW) of three-phase squirrel cage induction machines. The different windings have been designed and modeled using the same machine physical and electrical parameters. The Finite Element Model (FEM) of the machine for the different windings has been carried out. The results for the machine with FSDW and FSCW are compared to the results of the conventional double layer (CDL) with 8/9 chorded coil.
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- Authors: Muteba, Mbika , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Subjects: Induction machines , Fractional slots , Distributed performance , Unconventional windings , Torque ripple
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18322 , uj:15984 , Citation: Muteba M., Jimoh, A.A., Nicolae, D.V. Performance analysis of induction machines with unconventional winding configurations: 1-5.
- Description: Abstract: This paper presents the performance of fractional slots distributed windings (FSDW) and fractional slots concentrated windings (FSCW) of three-phase squirrel cage induction machines. The different windings have been designed and modeled using the same machine physical and electrical parameters. The Finite Element Model (FEM) of the machine for the different windings has been carried out. The results for the machine with FSDW and FSCW are compared to the results of the conventional double layer (CDL) with 8/9 chorded coil.
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Performance evaluation of a three-phase induction machine with auxilliary winding fed by a leading reactive current
- Muteba, M. C., Jimoh, Adisa A., Nicolae, Dan-Valentin, Ogunjuyigbe, A. S. O.
- Authors: Muteba, M. C. , Jimoh, Adisa A. , Nicolae, Dan-Valentin , Ogunjuyigbe, A. S. O.
- Date: 2008
- Subjects: Electric machines , Induction machines
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18639 , uj:16025 , Citation: Ogunjuyigbe, A.S.O., Jimoh, A.A. & Nicolae, D.V. 2008. Performance evaluation of a three-phase induction motor with auxiliary winding fed by a leading reactive current. The IASTED International Conrference on Power and Energy Systems, 8-10 September, Gaborone, Botswana.
- Description: Abstract In this paper the performance of three-phase induction machine equipped with a three-phase auxiliary winding which is only magnetically coupled to the stator main winding is evaluated. A capacitive load is connected in parallel to each phase of the auxiliary winding and serves to inject a leading reactive current into the machine. Steady state and dynamic performance of the machine are evaluated under various loading and compensative conditions. The experimental results show that it possible to obtain a comparatively good power factor with a fixed capacitive load for various loadings of the asynchronous machine.
- Full Text:
- Authors: Muteba, M. C. , Jimoh, Adisa A. , Nicolae, Dan-Valentin , Ogunjuyigbe, A. S. O.
- Date: 2008
- Subjects: Electric machines , Induction machines
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18639 , uj:16025 , Citation: Ogunjuyigbe, A.S.O., Jimoh, A.A. & Nicolae, D.V. 2008. Performance evaluation of a three-phase induction motor with auxiliary winding fed by a leading reactive current. The IASTED International Conrference on Power and Energy Systems, 8-10 September, Gaborone, Botswana.
- Description: Abstract In this paper the performance of three-phase induction machine equipped with a three-phase auxiliary winding which is only magnetically coupled to the stator main winding is evaluated. A capacitive load is connected in parallel to each phase of the auxiliary winding and serves to inject a leading reactive current into the machine. Steady state and dynamic performance of the machine are evaluated under various loading and compensative conditions. The experimental results show that it possible to obtain a comparatively good power factor with a fixed capacitive load for various loadings of the asynchronous machine.
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Power supply from the high voltage transmission lines Part 1: conditions, principles and tapping from HVAC lines
- Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Powerline ampacity , Voltage-frequency converters , Transmitting electricity
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21283 , uj:16134 , ISSN: 1609-3224 , Citation:Jimoh, A.A. & Nicolae, D.V.2007. Power supply from the high voltage transmission lines Part 1: Conditions, principles and tapping from HVAC lines. Quantum-The Journal for Professionals:23-27, September 2007.
- Description: Abstract: Electric power may be tapped straight from the high voltage transmission lines either for consumption to meet the needs of rural and remote areas, and telecommunication establishments located in remote sites; or as a scheme to enhance the capacity of another utility or grid along a trans-national or trans-continental transmission corridor. The importance and interests the technologies to accomplish this has generated necessitate the need for a review of the state of the art of this subject so as to delimit research actions and allow research interests to be appropriately promulgated. This paper therefore reviews, in two parts, the state of the art of tapping electric power from HV and EHV ac and dc transmission lines. Part one focuses on the general conditions for tapping, presents the principles on which tapping methods are based, reviews methods for tapping from HVAC transmission systems, and concludes with a general discussion on tapping from HVAC. The companion paper completes the study, by presenting the part two of the work.
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- Authors: Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2007
- Subjects: Powerline ampacity , Voltage-frequency converters , Transmitting electricity
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21283 , uj:16134 , ISSN: 1609-3224 , Citation:Jimoh, A.A. & Nicolae, D.V.2007. Power supply from the high voltage transmission lines Part 1: Conditions, principles and tapping from HVAC lines. Quantum-The Journal for Professionals:23-27, September 2007.
- Description: Abstract: Electric power may be tapped straight from the high voltage transmission lines either for consumption to meet the needs of rural and remote areas, and telecommunication establishments located in remote sites; or as a scheme to enhance the capacity of another utility or grid along a trans-national or trans-continental transmission corridor. The importance and interests the technologies to accomplish this has generated necessitate the need for a review of the state of the art of this subject so as to delimit research actions and allow research interests to be appropriately promulgated. This paper therefore reviews, in two parts, the state of the art of tapping electric power from HV and EHV ac and dc transmission lines. Part one focuses on the general conditions for tapping, presents the principles on which tapping methods are based, reviews methods for tapping from HVAC transmission systems, and concludes with a general discussion on tapping from HVAC. The companion paper completes the study, by presenting the part two of the work.
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Power supply from the high voltage transmission lines part 2 : tapping from HVDC lines, design and system interactions
- Nicolae, Dan-Valentin, Jimoh, Adisa A.
- Authors: Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2007
- Subjects: Transmitting electricity , Voltage-frequency converters
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21325 , uj:16140 , ISSN:1609-3224 , Citation: Jimoh, A.A. & Nicolae, D.V. 2007. power supply from the high voltage transmission lines part 2 : tapping from HVDC lines - design and system interactions. Quantum - The Journal for Professionals:5-9, December 2007.
- Description: Tapping tools , Abstract: Electric power may be tapped straight from the high voltage transmission lines either for consumption to meet the needs of rural and remote areas, and telecommunication establishments located in remote sites; or as a scheme to enhance the capacity of another utility or grid along a trans-national or trans-continental transmission corridor. The importance and interests the technologies to accomplish this has generated necessitate the need for a review of the state of the art of this subject so as to delimit research actions and allow research interests to be appropriately promulgated. In the first part of this work the principle, conditions and methods for tapping from HVAC lines have been discussed. This paper completes the study by looking at tapping from the HVDC transmission systems. The principles on which tapping methods from HVDC system is based are presented; and various methods, existing and novel, for multiterminal operation or integrating small tapping into HVDC links are reviewed. The paper ends with a general discussion of tapping from HVDC, and concludes with a presentation of the future direction.
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- Authors: Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2007
- Subjects: Transmitting electricity , Voltage-frequency converters
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21325 , uj:16140 , ISSN:1609-3224 , Citation: Jimoh, A.A. & Nicolae, D.V. 2007. power supply from the high voltage transmission lines part 2 : tapping from HVDC lines - design and system interactions. Quantum - The Journal for Professionals:5-9, December 2007.
- Description: Tapping tools , Abstract: Electric power may be tapped straight from the high voltage transmission lines either for consumption to meet the needs of rural and remote areas, and telecommunication establishments located in remote sites; or as a scheme to enhance the capacity of another utility or grid along a trans-national or trans-continental transmission corridor. The importance and interests the technologies to accomplish this has generated necessitate the need for a review of the state of the art of this subject so as to delimit research actions and allow research interests to be appropriately promulgated. In the first part of this work the principle, conditions and methods for tapping from HVAC lines have been discussed. This paper completes the study by looking at tapping from the HVDC transmission systems. The principles on which tapping methods from HVDC system is based are presented; and various methods, existing and novel, for multiterminal operation or integrating small tapping into HVDC links are reviewed. The paper ends with a general discussion of tapping from HVDC, and concludes with a presentation of the future direction.
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Reconfiguration and load balancing in the LV and MV distribution networks for optimal performance
- Siti, Mukwanga W., Nicolae, Dan-Valentin, Jimoh, Adisa A., Ukil, Abhisek
- Authors: Siti, Mukwanga W. , Nicolae, Dan-Valentin , Jimoh, Adisa A. , Ukil, Abhisek
- Date: 2007
- Subjects: Heuristic algorithms , Phase transformations
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18815 , uj:16046 , Citation: Siti, M.W. et al. 2007. Reconfiguration and load balancing in the LV and MV distribution networks for optimal performance. IEEE Transactions on Power Delivery, 22(4):2534-2540. DOI:10.1109/TPWRD.2007..905581
- Description: Abstract: To get the distribution network to operate at its optimum performance in an automated distribution system reconfiguration was been proposed and researched. Considering, however, that optimum performance implies minimum loss, no overloading of transformers and cables, correct voltage profile, and absence of phase voltage and current imbalances, network reconfiguration alone is insufficient. It has to be complemented with techniques for phase rearrangement between the distribution transformer banks and the specific primary feeder with a radial structure and dynamic phase and load balancing along a feeder with a radial structure. This paper contributes such a technique at the low-voltage and medium-voltage levels of a distribution network simultaneously with reconfiguration at both levels. While the neural network is adopted for the network reconfiguration problem, this paper introduces a heuristic method for the phase balancing/loss minimization problem. A comparison of the heuristic algorithm with that of the neural network shows the former to be more robust. The approach proposed here, therefore for the combined problem, uses the neural network in conjunction with a heuristic method which enables different reconfiguration switches to be turned on/off and connected consumers to be switched between different phases to keep the phases balanced. An application example of the proposed method using real data is presented
- Full Text:
- Authors: Siti, Mukwanga W. , Nicolae, Dan-Valentin , Jimoh, Adisa A. , Ukil, Abhisek
- Date: 2007
- Subjects: Heuristic algorithms , Phase transformations
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18815 , uj:16046 , Citation: Siti, M.W. et al. 2007. Reconfiguration and load balancing in the LV and MV distribution networks for optimal performance. IEEE Transactions on Power Delivery, 22(4):2534-2540. DOI:10.1109/TPWRD.2007..905581
- Description: Abstract: To get the distribution network to operate at its optimum performance in an automated distribution system reconfiguration was been proposed and researched. Considering, however, that optimum performance implies minimum loss, no overloading of transformers and cables, correct voltage profile, and absence of phase voltage and current imbalances, network reconfiguration alone is insufficient. It has to be complemented with techniques for phase rearrangement between the distribution transformer banks and the specific primary feeder with a radial structure and dynamic phase and load balancing along a feeder with a radial structure. This paper contributes such a technique at the low-voltage and medium-voltage levels of a distribution network simultaneously with reconfiguration at both levels. While the neural network is adopted for the network reconfiguration problem, this paper introduces a heuristic method for the phase balancing/loss minimization problem. A comparison of the heuristic algorithm with that of the neural network shows the former to be more robust. The approach proposed here, therefore for the combined problem, uses the neural network in conjunction with a heuristic method which enables different reconfiguration switches to be turned on/off and connected consumers to be switched between different phases to keep the phases balanced. An application example of the proposed method using real data is presented
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Simulation of six phase induction machine using the Matlab/Simulink environment
- Ogunjuyigbe, A. S. O., Nnachi, A. F., Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Ogunjuyigbe, A. S. O. , Nnachi, A. F. , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2008
- Subjects: MATLAB , SIMULINK , Electric machinery , Converter simulations , Computer-aided engineering
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18518 , uj:16010 , Citation: Ogunjuyigbe, A.S.O. et al. 2008. Simulation of six phase split winding induction machine using the MATLAB/SIMULINK environment. Journal for Electrical Enginnering, 8(3): 33-39
- Description: Abstract: Six-phase induction machine presents several benefits over their conventional three-phase counterpart. This paper thus presents the model and described in detail the simulation of a Six-phase split winding induction machine in a Matlab/Simulink environment. The Simulink model is built in such a flexible manner such that various variables of the machine can be accessed easily for further purposes such as control. Finally, simulation results showing free acceleration as well as dynamic response of the machine were presented for both direct ac supply and the PWM inverter voltage source.
- Full Text:
- Authors: Ogunjuyigbe, A. S. O. , Nnachi, A. F. , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2008
- Subjects: MATLAB , SIMULINK , Electric machinery , Converter simulations , Computer-aided engineering
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18518 , uj:16010 , Citation: Ogunjuyigbe, A.S.O. et al. 2008. Simulation of six phase split winding induction machine using the MATLAB/SIMULINK environment. Journal for Electrical Enginnering, 8(3): 33-39
- Description: Abstract: Six-phase induction machine presents several benefits over their conventional three-phase counterpart. This paper thus presents the model and described in detail the simulation of a Six-phase split winding induction machine in a Matlab/Simulink environment. The Simulink model is built in such a flexible manner such that various variables of the machine can be accessed easily for further purposes such as control. Finally, simulation results showing free acceleration as well as dynamic response of the machine were presented for both direct ac supply and the PWM inverter voltage source.
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Strategy for power quality improvement and maximum demand smoothing
- Siti, Willy M., Jimoh, Adisa A., Nicolae, Dan-Valentin
- Authors: Siti, Willy M. , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2005
- Subjects: Electric power transmission , Data transmission modes , data switching methods
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21725 , uj:16154 , ISBN;0780392531 , Citation: Siti,W.M., Jimoh, A.A. & Nicolae, D.V. 2005. Strategy for power quality improvement and maximum demand smoothing,“IECON’05 Conference”, Raleigh, USA, November 2005. 31st Annual conference of IEEE. pp6. DOI:10.1109/IECON.2005.1568907
- Description: Abstract: In this paper, a distributed strategy for improving the power quality and maximum demand smoothing is presented. Many authors have presented the power quality improvement as a centralized issue, which implies high power capability of compensators. Based on multi-functionality of specific switching-mode converters, a decentralised model is presented. A discussion of simultaneity of different functions is presented in details. The results of this paper are intended to be a guideline for application designers
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- Authors: Siti, Willy M. , Jimoh, Adisa A. , Nicolae, Dan-Valentin
- Date: 2005
- Subjects: Electric power transmission , Data transmission modes , data switching methods
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21725 , uj:16154 , ISBN;0780392531 , Citation: Siti,W.M., Jimoh, A.A. & Nicolae, D.V. 2005. Strategy for power quality improvement and maximum demand smoothing,“IECON’05 Conference”, Raleigh, USA, November 2005. 31st Annual conference of IEEE. pp6. DOI:10.1109/IECON.2005.1568907
- Description: Abstract: In this paper, a distributed strategy for improving the power quality and maximum demand smoothing is presented. Many authors have presented the power quality improvement as a centralized issue, which implies high power capability of compensators. Based on multi-functionality of specific switching-mode converters, a decentralised model is presented. A discussion of simultaneity of different functions is presented in details. The results of this paper are intended to be a guideline for application designers
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Zero voltage switching used for a reversible DC-DC converter
- Nicolae, Dan-Valentin, Jimoh, Adisa A., Cernat, M.
- Authors: Nicolae, Dan-Valentin , Jimoh, Adisa A. , Cernat, M.
- Date: 2008
- Subjects: Electric current converters
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18494 , uj:16007 , Citation: Nicolae, D.V., Jimoh, A.A. & Cernat, M. 2008. Zero voltage switching used for a reversible DC-DC converter. The IASTED International Conference on Circuits and Systems, 10-20 November, 2008, Kailua-Kona, USA. , ISBN: 978-0-88986-753-6
- Description: Abstract A novel bi-directional dc-dc converter with Zero Voltage Switching (ZVS) and interleaving for dual voltage systems in automobiles is presented. A variable frequency extended band hysteretic current control method is proposed. In comparison with classical fixed frequency current control PWM, the reverse polarity peak current needed for ZVS operation is kept constant. Inductor current ripple decreases with load reduction. Automatic changes in operation between buck and boost modes are accomplished without transient currents. Converter simulations are carried out using Matlab/Simulink platform.
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- Authors: Nicolae, Dan-Valentin , Jimoh, Adisa A. , Cernat, M.
- Date: 2008
- Subjects: Electric current converters
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18494 , uj:16007 , Citation: Nicolae, D.V., Jimoh, A.A. & Cernat, M. 2008. Zero voltage switching used for a reversible DC-DC converter. The IASTED International Conference on Circuits and Systems, 10-20 November, 2008, Kailua-Kona, USA. , ISBN: 978-0-88986-753-6
- Description: Abstract A novel bi-directional dc-dc converter with Zero Voltage Switching (ZVS) and interleaving for dual voltage systems in automobiles is presented. A variable frequency extended band hysteretic current control method is proposed. In comparison with classical fixed frequency current control PWM, the reverse polarity peak current needed for ZVS operation is kept constant. Inductor current ripple decreases with load reduction. Automatic changes in operation between buck and boost modes are accomplished without transient currents. Converter simulations are carried out using Matlab/Simulink platform.
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