Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367629
T. El-fetoh
This paper presents the procedures required to determine the locations and sizes of multiple-active power filters (APFs) to reduce harmonic distortion in a power system with harmonic sources. The objective function is to minimize the APFs injection currents while satisfying harmonic voltages, total harmonic voltage distortions within IEEE-519 recommended limits and the maximum rating current limit of each installed APF. The APFs are located at the points having harmonic sources or higher harmonic distortions, while minimizing injection currents. The ANN Model is developed to determine size and location of APF. A typical 28-bus distribution system is selected to verify the validity of the proposed procedures
{"title":"Harmonic Intelligent Control with Active Power Filter","authors":"T. El-fetoh","doi":"10.1109/UPEC.2006.367629","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367629","url":null,"abstract":"This paper presents the procedures required to determine the locations and sizes of multiple-active power filters (APFs) to reduce harmonic distortion in a power system with harmonic sources. The objective function is to minimize the APFs injection currents while satisfying harmonic voltages, total harmonic voltage distortions within IEEE-519 recommended limits and the maximum rating current limit of each installed APF. The APFs are located at the points having harmonic sources or higher harmonic distortions, while minimizing injection currents. The ANN Model is developed to determine size and location of APF. A typical 28-bus distribution system is selected to verify the validity of the proposed procedures","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127958681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367767
E. Hreinsson
An activity based distribution cost model, APOWER, is applied to a rural distribution system, where multiple classes or bilateral contracts of energy are assumed. In particular, primary and secondary energy classes are considered where these classes share both system costs and benefits. Also, the cost of losses is shared by explicitly treating power and energy losses in the model. Different approaches to sharing other cost factors are suggested. The model is tested on an actual rural distribution network in Iceland and delivery and distribution costs are compared, with respect to rural and community delivery, voltage levels and bilateral contracts. Results can form a basis for designing transmission and distribution tariffs for network companies and can help shape the regulating environment for these companies by developing a unified framework in distribution system cost estimation
{"title":"Cost Analysis in a Rural Power Distribution System","authors":"E. Hreinsson","doi":"10.1109/UPEC.2006.367767","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367767","url":null,"abstract":"An activity based distribution cost model, APOWER, is applied to a rural distribution system, where multiple classes or bilateral contracts of energy are assumed. In particular, primary and secondary energy classes are considered where these classes share both system costs and benefits. Also, the cost of losses is shared by explicitly treating power and energy losses in the model. Different approaches to sharing other cost factors are suggested. The model is tested on an actual rural distribution network in Iceland and delivery and distribution costs are compared, with respect to rural and community delivery, voltage levels and bilateral contracts. Results can form a basis for designing transmission and distribution tariffs for network companies and can help shape the regulating environment for these companies by developing a unified framework in distribution system cost estimation","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131083017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367541
S. Eio, N. Shammas
The aim of the work presented in this paper is to gain an insight in the switching transient of the power diode, reverse recovery, and methods of reducing the reverse recovery time. The limitations have also been discussed in using carrier lifetime killing such as by doping gold and platinum during the manufacturing process, high-energy irradiation before metallisation and after encapsulation, and a recent research to associate monolithically devices to obtain low conduction losses and high switching ability
{"title":"Switching Transients of Power Diode","authors":"S. Eio, N. Shammas","doi":"10.1109/UPEC.2006.367541","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367541","url":null,"abstract":"The aim of the work presented in this paper is to gain an insight in the switching transient of the power diode, reverse recovery, and methods of reducing the reverse recovery time. The limitations have also been discussed in using carrier lifetime killing such as by doping gold and platinum during the manufacturing process, high-energy irradiation before metallisation and after encapsulation, and a recent research to associate monolithically devices to obtain low conduction losses and high switching ability","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131584847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367595
F. Kavehnia, Hossein Seifi, H. Keivani, M. R. Askari
In this paper a new approach will be used for optimal coordination of directional over current (DOC) relays based on genetic algorithm. In this approach, optimal operation characteristics and also optimal current setting and time setting of each OC relays will be determined simultaneously. Also, a new objective function will be used which is different from ordinary methods such as simplex, two phase simplex, dual simplex. Improvement of selectivity and speed of the protection system, obtaining the absolute optimal point of the optimization problem are the specifications of the proposed approach. Numerical results obtained with the proposed method for a real power system are presented
{"title":"Optimal Coordination of Directional Over Current Relays in Power System Using Genetic Algorithm","authors":"F. Kavehnia, Hossein Seifi, H. Keivani, M. R. Askari","doi":"10.1109/UPEC.2006.367595","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367595","url":null,"abstract":"In this paper a new approach will be used for optimal coordination of directional over current (DOC) relays based on genetic algorithm. In this approach, optimal operation characteristics and also optimal current setting and time setting of each OC relays will be determined simultaneously. Also, a new objective function will be used which is different from ordinary methods such as simplex, two phase simplex, dual simplex. Improvement of selectivity and speed of the protection system, obtaining the absolute optimal point of the optimization problem are the specifications of the proposed approach. Numerical results obtained with the proposed method for a real power system are presented","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132645347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367640
W. Stemmet, G. Atkinson-Hope
The focus of this paper is to define and identify a harmonic offender and develop a simulation method to investigate this concept in an interconnected power system containing multiple six-pulse drives. The IEEE 519 recommended practice provides indices to determine distortion as well as recommending limits within which systems containing harmonics should operate. However, no specific method is provided for determining whether or not the harmonic spectrum magnitudes and phase angles of a new drive that is to be installed in a system that already contains more than one six-pulse drive will be a harmonic offender or not. When only one drive is present in a system, its harmonic spectrum phase angles has no effect on the distortion index results. Only harmonic magnitudes influence distortion. However, when multiple drives are connected in a system, the harmonic currents from each source add vectorially at the point of common coupling. As a result, the harmonic distortion is highly dependant on the method in which the harmonic current spectrum angles are modelled. Whether a drive is a harmonic offender or not in a given system thus depends upon the modelling of drives taking into account the harmonic spectrum phase angles. To enhance the understanding of modelling harmonic spectrum phase angles, the two methods (voltage and current method) are compared and a recommendation as to which method should be used is made. Three case studies are conducted to show the usefulness of the developed method.
{"title":"Simulation Method for Identifying A Harmonic Offender in a Power System Containing Multiple Six-Pulse Drives","authors":"W. Stemmet, G. Atkinson-Hope","doi":"10.1109/UPEC.2006.367640","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367640","url":null,"abstract":"The focus of this paper is to define and identify a harmonic offender and develop a simulation method to investigate this concept in an interconnected power system containing multiple six-pulse drives. The IEEE 519 recommended practice provides indices to determine distortion as well as recommending limits within which systems containing harmonics should operate. However, no specific method is provided for determining whether or not the harmonic spectrum magnitudes and phase angles of a new drive that is to be installed in a system that already contains more than one six-pulse drive will be a harmonic offender or not. When only one drive is present in a system, its harmonic spectrum phase angles has no effect on the distortion index results. Only harmonic magnitudes influence distortion. However, when multiple drives are connected in a system, the harmonic currents from each source add vectorially at the point of common coupling. As a result, the harmonic distortion is highly dependant on the method in which the harmonic current spectrum angles are modelled. Whether a drive is a harmonic offender or not in a given system thus depends upon the modelling of drives taking into account the harmonic spectrum phase angles. To enhance the understanding of modelling harmonic spectrum phase angles, the two methods (voltage and current method) are compared and a recommendation as to which method should be used is made. Three case studies are conducted to show the usefulness of the developed method.","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128212299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367596
Biao Zhang, J.H. He, Z. Bo, B. Caunce, A. Klimek
This paper proposes a new current mode derived by a new modal transformation technique, the alpha mode. The mode is used to detect and distinguish between internal and external faults for power line protection, based on a new transient directional comparison technique using current alone. The technique uses the symmetrical component to replace Clark or Karrenbauer transformation to decouple the three phase transient current signals. Wavelet transform is then applied to the positive sequence component to produce the modular maximum, which are subsequently used to distinguish between internal and external faults. The modular maximum of the wavelet transform for the new alpha mode have the same polarity at both ends of the line for internal faults and opposite polarity for external faults. Theoretical analysis and extensive simulation studies show that the technique is able to give correct responses for all fault types
{"title":"Transient Directional Protection Based on the Transformation of Positive Sequence Component","authors":"Biao Zhang, J.H. He, Z. Bo, B. Caunce, A. Klimek","doi":"10.1109/UPEC.2006.367596","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367596","url":null,"abstract":"This paper proposes a new current mode derived by a new modal transformation technique, the alpha mode. The mode is used to detect and distinguish between internal and external faults for power line protection, based on a new transient directional comparison technique using current alone. The technique uses the symmetrical component to replace Clark or Karrenbauer transformation to decouple the three phase transient current signals. Wavelet transform is then applied to the positive sequence component to produce the modular maximum, which are subsequently used to distinguish between internal and external faults. The modular maximum of the wavelet transform for the new alpha mode have the same polarity at both ends of the line for internal faults and opposite polarity for external faults. Theoretical analysis and extensive simulation studies show that the technique is able to give correct responses for all fault types","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133195901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367621
S. Mahmoud, K.G. Ahmed, R.F. Aboul-Fetouh, F.M. Maayouf
This paper evaluates the potential of demand side management "DSM" (that includes energy conservation and load management activities) in different governmental subsectors in Egypt based on the demand pattern analysis of different types of these subsectors obtained from the time-of-use (TOU) meters and energy audits carried out at some governmental customers. In addition, the impact of DSM in the total governmental sector on the demand forecast and consequently on the power system expansion plan is presented
{"title":"Assessment of DSM Potential in the Governmental Sector in Egypt and its Effect on the National Power System Development","authors":"S. Mahmoud, K.G. Ahmed, R.F. Aboul-Fetouh, F.M. Maayouf","doi":"10.1109/UPEC.2006.367621","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367621","url":null,"abstract":"This paper evaluates the potential of demand side management \"DSM\" (that includes energy conservation and load management activities) in different governmental subsectors in Egypt based on the demand pattern analysis of different types of these subsectors obtained from the time-of-use (TOU) meters and energy audits carried out at some governmental customers. In addition, the impact of DSM in the total governmental sector on the demand forecast and consequently on the power system expansion plan is presented","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"77 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113933231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367533
R. Pereira, A.J.C. Pereira, C. Ferreira, J. Pinto, F. Barbosa
In recent years, the electricity sector undergoes a restructuring process, operationally and commercially, moving from a vertical integrated model to a market oriented model. With past and current difficulties in building new transmission lines and the significant increase in power transactions associated with competitive electricity markets, maintaining system security, with special regard to voltage instability/collapse issues, is more than ever one of the main concerns for market and system operators. Voltage is most readily controlled by adjustments to reactive power injections in power system. Reactive power can be produced and absorbed by both generation and transmission equipment. System operators, transmission owners, generators, customers, power marketers and government regulators need to pay close attention to voltage control. This paper is devoted to the study of the reactive power support for dynamic voltage stability of a restructured electric power system. A severe contingency situation was simulated. The automatic voltage regulators of the generating units and the mechanically switched shunt capacitors were modelled. The simulation results were obtained using the commercial transient software package EUROSTAG. Finally, some conclusions that provide a better understanding of the voltage collapse phenomena are pointed out.
{"title":"Reactive Power Support in the Dynamic Voltage Stability Assessment of a Restructured Electric Power System","authors":"R. Pereira, A.J.C. Pereira, C. Ferreira, J. Pinto, F. Barbosa","doi":"10.1109/UPEC.2006.367533","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367533","url":null,"abstract":"In recent years, the electricity sector undergoes a restructuring process, operationally and commercially, moving from a vertical integrated model to a market oriented model. With past and current difficulties in building new transmission lines and the significant increase in power transactions associated with competitive electricity markets, maintaining system security, with special regard to voltage instability/collapse issues, is more than ever one of the main concerns for market and system operators. Voltage is most readily controlled by adjustments to reactive power injections in power system. Reactive power can be produced and absorbed by both generation and transmission equipment. System operators, transmission owners, generators, customers, power marketers and government regulators need to pay close attention to voltage control. This paper is devoted to the study of the reactive power support for dynamic voltage stability of a restructured electric power system. A severe contingency situation was simulated. The automatic voltage regulators of the generating units and the mechanically switched shunt capacitors were modelled. The simulation results were obtained using the commercial transient software package EUROSTAG. Finally, some conclusions that provide a better understanding of the voltage collapse phenomena are pointed out.","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128829468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367547
H. Keivani, M. Askari, F. Kavehnia, Aghdam, A. Mohammadi
A number of modulation strategies are used in multi-level power conversion applications. This paper is focused on novel multi-carrier PWM methods which have been extended for use in cascaded H-bridge multi-level inverter. Novel multi-carrier PWM method can be optimized or balanced the switch utilization in cascaded H-bridge multi-level inverter. Five-level cascaded H-bridge multi-level inverter has been simulated and controlled with the novel multi-carrier PWM proposed in this paper to act as a voltage-source inverter (VSI)
{"title":"Novel Multi-Carrier PWM Method for a Three-Phase Cascaded H-Bridge Multi-Level Inverter","authors":"H. Keivani, M. Askari, F. Kavehnia, Aghdam, A. Mohammadi","doi":"10.1109/UPEC.2006.367547","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367547","url":null,"abstract":"A number of modulation strategies are used in multi-level power conversion applications. This paper is focused on novel multi-carrier PWM methods which have been extended for use in cascaded H-bridge multi-level inverter. Novel multi-carrier PWM method can be optimized or balanced the switch utilization in cascaded H-bridge multi-level inverter. Five-level cascaded H-bridge multi-level inverter has been simulated and controlled with the novel multi-carrier PWM proposed in this paper to act as a voltage-source inverter (VSI)","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115220008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367769
J. Evans
This paper investigates current unbalance in parallel cable interconnector circuits. Several instances have been observed where an MV switchboard loses supply during a motor starting transient. In each instance the affected switchboard was supplied via two interconnector cables operating in parallel. During motor starting, the transient current was not shared equally between the interconnector red, blue and yellow phases. The protection on each interconnector interpreted the unbalance in the phases as an earth fault and initiated a trip. To establish that the unbalance is not due to load or current transformer spill current, steady-state and transient measurements have been made. Steady-state and transient PSCAD simulations have been performed to investigate possible causes of the unequal current sharing between parallel interconnectors.
{"title":"Unbalance in Parallel Interconnector Circuits","authors":"J. Evans","doi":"10.1109/UPEC.2006.367769","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367769","url":null,"abstract":"This paper investigates current unbalance in parallel cable interconnector circuits. Several instances have been observed where an MV switchboard loses supply during a motor starting transient. In each instance the affected switchboard was supplied via two interconnector cables operating in parallel. During motor starting, the transient current was not shared equally between the interconnector red, blue and yellow phases. The protection on each interconnector interpreted the unbalance in the phases as an earth fault and initiated a trip. To establish that the unbalance is not due to load or current transformer spill current, steady-state and transient measurements have been made. Steady-state and transient PSCAD simulations have been performed to investigate possible causes of the unequal current sharing between parallel interconnectors.","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125864179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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