Pub Date : 2006-09-01DOI: 10.1109/UPEC.2006.367639
J. Cobben, C. Rong, W. Kling, J. Myrzik
Measurements during the last eight years show an increasing level of PIt, an indicator used for the flicker level. Furthermore, almost 50% of all technical customer complaints are flicker problems. The short-circuit power on the connection point is a very important parameter for controlling the fast voltage variations that lead to flicker. However, a high short circuit level can not be established unless investments in the low voltage grid are made. Analyzing the database of customers complaints shows that in only 25% of all cases the short-circuit power is less than the minimum value given in the national grid code, as indication. So other solutions, without investment in the network, are needed
{"title":"The Cheapest Way to Solve the Flicker Problem","authors":"J. Cobben, C. Rong, W. Kling, J. Myrzik","doi":"10.1109/UPEC.2006.367639","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367639","url":null,"abstract":"Measurements during the last eight years show an increasing level of PIt, an indicator used for the flicker level. Furthermore, almost 50% of all technical customer complaints are flicker problems. The short-circuit power on the connection point is a very important parameter for controlling the fast voltage variations that lead to flicker. However, a high short circuit level can not be established unless investments in the low voltage grid are made. Analyzing the database of customers complaints shows that in only 25% of all cases the short-circuit power is less than the minimum value given in the national grid code, as indication. So other solutions, without investment in the network, are needed","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"7 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":"114566721","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.2006.367626
M. Abderrazzaq
The voltage dip is one of power quality problems, which has started to affect distribution networks from the beginning of the last decade. Although the dip is attributed to a wide range of causes, short circuits are the most common sources of this problem. The present paper shows a case study investigating the dip in a low voltage (LV) distribution network. The change of fault position in adjacent LV feeders causes a systematic variation of voltage dip level measured at different busbars. A concept of relative dip is introduced. The impact of load type, including its contribution to short circuit current and voltage dip, is discussed. The simulation results show a possibility of classifying the dip impact on equipment according to the location of fault. The paper addresses the need to correlate the characteristics of dip and protection systems in order to improve the voltage profile and prevent serious dips
{"title":"Assessment of Voltage Dip Staging for Low Voltage Systems","authors":"M. Abderrazzaq","doi":"10.1109/UPEC.2006.367626","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367626","url":null,"abstract":"The voltage dip is one of power quality problems, which has started to affect distribution networks from the beginning of the last decade. Although the dip is attributed to a wide range of causes, short circuits are the most common sources of this problem. The present paper shows a case study investigating the dip in a low voltage (LV) distribution network. The change of fault position in adjacent LV feeders causes a systematic variation of voltage dip level measured at different busbars. A concept of relative dip is introduced. The impact of load type, including its contribution to short circuit current and voltage dip, is discussed. The simulation results show a possibility of classifying the dip impact on equipment according to the location of fault. The paper addresses the need to correlate the characteristics of dip and protection systems in order to improve the voltage profile and prevent serious dips","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"111 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":"115814576","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.2006.367759
M. Chindris, B. Tomoiagă, P. Taylor, L. Cipcigan
The reconstruction or revitalization of electrical substations provides the possibility to introduce very powerful new switchgears, and as a result, to simplify the substation circuit diagram. Taking into account these tendencies, the authors propose a systematical method for establishing the optimal structure of electrical substations for increasing the operational level of reliability at the lowest economic cost. The graph theory is used to solve this particular problem. A (multi)graph will be associated to the network under study, where the bus system are taken for nodes, while the power lines and the (auto)transformers are considered as branches. By developing this model, the task of finding the critical equipment is reduced to the determination of (multi)graph critical nodes (articulation points) and critical branches (isthmuses). The paper presents an original method that, using the determination of critical equipment (systems of buses, transformers, power lines), indicates the most appropriate (minimal) structure for electrical substation circuit diagrams
{"title":"The Identification of Critical Equipment and Optimum Configurations for Electrical Substations","authors":"M. Chindris, B. Tomoiagă, P. Taylor, L. Cipcigan","doi":"10.1109/UPEC.2006.367759","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367759","url":null,"abstract":"The reconstruction or revitalization of electrical substations provides the possibility to introduce very powerful new switchgears, and as a result, to simplify the substation circuit diagram. Taking into account these tendencies, the authors propose a systematical method for establishing the optimal structure of electrical substations for increasing the operational level of reliability at the lowest economic cost. The graph theory is used to solve this particular problem. A (multi)graph will be associated to the network under study, where the bus system are taken for nodes, while the power lines and the (auto)transformers are considered as branches. By developing this model, the task of finding the critical equipment is reduced to the determination of (multi)graph critical nodes (articulation points) and critical branches (isthmuses). The paper presents an original method that, using the determination of critical equipment (systems of buses, transformers, power lines), indicates the most appropriate (minimal) structure for electrical substation circuit diagrams","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"101 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":"123161608","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.2006.367596
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.2006.367595
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.2006.367636
W. Hosny, R. Holček
Genetic algorithms (GA) are used to optimize the performance of a full-wave AC to DC converter in terms of improving its input supply power factor and minimising its output ripple factor. GA is used for optimization on the ground of their computation versatility and robustness. The converter topology and the optimisation control strategy is described. The GA theory and its application to the control strategy is explained. Four controller parameters are treated as Genes in the GA and are optimised for achievement of best fit of the controller objectives. This process is carried out to yield results for various loads of the converter. Further, these results, in conjunction with least square extrapolation technique, are used to develop an adaptive controller for the converter. Simulation results for the converter operating under this adaptive controller are presented.
{"title":"Performance Optimisation of a Full Wave AC to DC Converter Using Genetic Algorithms","authors":"W. Hosny, R. Holček","doi":"10.1109/UPEC.2006.367636","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367636","url":null,"abstract":"Genetic algorithms (GA) are used to optimize the performance of a full-wave AC to DC converter in terms of improving its input supply power factor and minimising its output ripple factor. GA is used for optimization on the ground of their computation versatility and robustness. The converter topology and the optimisation control strategy is described. The GA theory and its application to the control strategy is explained. Four controller parameters are treated as Genes in the GA and are optimised for achievement of best fit of the controller objectives. This process is carried out to yield results for various loads of the converter. Further, these results, in conjunction with least square extrapolation technique, are used to develop an adaptive controller for the converter. Simulation results for the converter operating under this adaptive controller are presented.","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"35 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":"115146799","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.2006.367721
I. Ashraf, M. Danish, E. Fernandez
Using the past diffusion trend of renewable energy technology for power generation in India, results of an attempt to project the future dissemination levels have been presented in this work. The likely contribution of solar photovoltaic (SPV) considered in this study to the projected energy demand for power generation in India has been estimated.
{"title":"Solar Photo Voltaic for Power Generation in India: Projected Level of Dissemination Using Technology Diffusion Models","authors":"I. Ashraf, M. Danish, E. Fernandez","doi":"10.1109/UPEC.2006.367721","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367721","url":null,"abstract":"Using the past diffusion trend of renewable energy technology for power generation in India, results of an attempt to project the future dissemination levels have been presented in this work. The likely contribution of solar photovoltaic (SPV) considered in this study to the projected energy demand for power generation in India has been estimated.","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"259 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":"115879920","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.2006.367611
F. Alrumayan, I. Cotton
This paper details a partial discharge measurement detection model that has been used to produce a test circuit suitable for detection of partial discharge at high frequencies. The circuit is designed to identify partial discharges in different insulating samples stressed by non-standard (including high frequency sine-waves and square waves). This is particularly important for the testing of equipment used in modern high voltage power electronic environments. The circuit was built and tested after carrying out simulations using the PSPICE software. The details of these simulations and the results collected are presented in this paper. The advantage of a balanced circuit measurement system is highlighted as well as the variance in predicted noise levels when different frequencies are used to energize the object under test. A comparison between the simulated circuit response and the experimental results is included
{"title":"Detection of Partial Discharges at High Frequencies","authors":"F. Alrumayan, I. Cotton","doi":"10.1109/UPEC.2006.367611","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367611","url":null,"abstract":"This paper details a partial discharge measurement detection model that has been used to produce a test circuit suitable for detection of partial discharge at high frequencies. The circuit is designed to identify partial discharges in different insulating samples stressed by non-standard (including high frequency sine-waves and square waves). This is particularly important for the testing of equipment used in modern high voltage power electronic environments. The circuit was built and tested after carrying out simulations using the PSPICE software. The details of these simulations and the results collected are presented in this paper. The advantage of a balanced circuit measurement system is highlighted as well as the variance in predicted noise levels when different frequencies are used to energize the object under test. A comparison between the simulated circuit response and the experimental results is included","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"211 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":"116398289","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.2006.367609
A. R. Al-Zyoud, A. Khraiwish, M. Shakarchi
Power system harmonics affect relay operation in many ways, they can reduce operating currents, increase or decrease operating time. Distance relays reach can be affected. This paper reviews relay performance in the presence of harmonics current the results are recorded
{"title":"Protective Relays Performance in a Harmonic Environment","authors":"A. R. Al-Zyoud, A. Khraiwish, M. Shakarchi","doi":"10.1109/UPEC.2006.367609","DOIUrl":"https://doi.org/10.1109/UPEC.2006.367609","url":null,"abstract":"Power system harmonics affect relay operation in many ways, they can reduce operating currents, increase or decrease operating time. Distance relays reach can be affected. This paper reviews relay performance in the presence of harmonics current the results are recorded","PeriodicalId":184186,"journal":{"name":"Proceedings of the 41st International Universities Power Engineering Conference","volume":"10 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":"121829017","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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