A. Bazavluk, A. Kuzmin, A. Telegin, I. Tsivilyov, A. Panchenko, I. Minzakirov
Mathematical model for analysis of transient processes at ground faults in the ungrounded long-distance transmission line is developed. Calculations show that along the transmission line there are areas having overvoltage ratios more than in the fault area. Results are in good agreement with experimental data obtained at ground fault experiments in different areas of the long-distance transmission line.
{"title":"Special features of transient processes at ground faults in long-distance transmission lines","authors":"A. Bazavluk, A. Kuzmin, A. Telegin, I. Tsivilyov, A. Panchenko, I. Minzakirov","doi":"10.1109/PQ.2012.6256225","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256225","url":null,"abstract":"Mathematical model for analysis of transient processes at ground faults in the ungrounded long-distance transmission line is developed. Calculations show that along the transmission line there are areas having overvoltage ratios more than in the fault area. Results are in good agreement with experimental data obtained at ground fault experiments in different areas of the long-distance transmission line.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133946625","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}
Reliability of power system each element affects all power supply network reliability. The existing relay protection (RP) is not always able to effectively provide the cable lines thermal protection, especially in electrical cable networks, the neutrals of which are not directly earthed. To attain it, Universal relay protection against phase to phase faults was developed and patented in Latvian Republic (LV 13554 B). The invention has three objectives: 1) to modify and supplement existing RP so that it ensures not only cable line RP against phase-to-phase faults but also cable metal sheath RP against double ground faults; 2) to insure that RP, in case of double ground fault switches off only one of faulted lines, the second line with its customer remaining on duty; 3) to assign the switching off priority to one or several faulted lines in case of double ground fault.
{"title":"Middle voltage cable power lines relay protection against double ground faults influence to power supply reliability","authors":"J. Rozenkrons, A. Staltmanis","doi":"10.1109/PQ.2012.6256224","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256224","url":null,"abstract":"Reliability of power system each element affects all power supply network reliability. The existing relay protection (RP) is not always able to effectively provide the cable lines thermal protection, especially in electrical cable networks, the neutrals of which are not directly earthed. To attain it, Universal relay protection against phase to phase faults was developed and patented in Latvian Republic (LV 13554 B). The invention has three objectives: 1) to modify and supplement existing RP so that it ensures not only cable line RP against phase-to-phase faults but also cable metal sheath RP against double ground faults; 2) to insure that RP, in case of double ground fault switches off only one of faulted lines, the second line with its customer remaining on duty; 3) to assign the switching off priority to one or several faulted lines in case of double ground fault.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123563272","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}
Due to the rapid growth of non-linear loads in power systems in recent decades, harmonic pollution is becoming more and more serious. Energy measurement devices are commonly designed for working at sine wave. In this paper the results of an analysis on different electricity meters used in distribution network under different load conditions are presented. Study shows that error of energy meter's reading depends on the type of the meter, harmonic distortion, reactive energy and direction of reactive power. Measured errors were higher than 6% under some conditions.
{"title":"Analysis of electricity meters under distorted load conditions","authors":"A. Haas, J. Niitsoo, P. Taklaja, I. Palu","doi":"10.1109/PQ.2012.6256239","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256239","url":null,"abstract":"Due to the rapid growth of non-linear loads in power systems in recent decades, harmonic pollution is becoming more and more serious. Energy measurement devices are commonly designed for working at sine wave. In this paper the results of an analysis on different electricity meters used in distribution network under different load conditions are presented. Study shows that error of energy meter's reading depends on the type of the meter, harmonic distortion, reactive energy and direction of reactive power. Measured errors were higher than 6% under some conditions.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117198233","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}
Over the years the power systems have become more stressed due to development of electricity markets and due to the connection of large amount of distributed generation. In order to guarantee reliable and secure system operation new approaches and technical solutions for network control should be implemented. Development of the power system monitoring and control equipment in recent years have enabled the engineers to build more sophisticated control and protection functions in order to increase the system security. Especially interesting possibilities are available when observable system includes Wide-Area based solutions. In this paper a brief overview of different Wide-Area solutions is provided and more sophisticated solutions based on Wide-Area measurements are proposed and analyzed in the context of Estonian power system security enhancement.
{"title":"Wide-Area applications for enhancement of Estonian power system security","authors":"J. Kilter, A. Reinson","doi":"10.1109/PQ.2012.6256218","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256218","url":null,"abstract":"Over the years the power systems have become more stressed due to development of electricity markets and due to the connection of large amount of distributed generation. In order to guarantee reliable and secure system operation new approaches and technical solutions for network control should be implemented. Development of the power system monitoring and control equipment in recent years have enabled the engineers to build more sophisticated control and protection functions in order to increase the system security. Especially interesting possibilities are available when observable system includes Wide-Area based solutions. In this paper a brief overview of different Wide-Area solutions is provided and more sophisticated solutions based on Wide-Area measurements are proposed and analyzed in the context of Estonian power system security enhancement.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131606448","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}
This paper posses the construction of the electrical machine, which has the ability to operate as a synchronous generator with electromagnetic excitation or double fed induction generator. This generator can be applied for slow speed applications without using the gearbox e.g. wind turbine. The generator is multi pole with all of the windings placed on the stator. Rotor is tooth-like and has no windings on it. Primary winding is three phase, secondary winding is one phase. The testing results and practical research are also presented in the paper.
{"title":"Testing results of slow speed electrical machine, that can operate as a synchronous or double fed induction generator","authors":"G. Diļevs, V. Pugachevs, N. Levins, E. Jakobsons","doi":"10.1109/PQ.2012.6256195","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256195","url":null,"abstract":"This paper posses the construction of the electrical machine, which has the ability to operate as a synchronous generator with electromagnetic excitation or double fed induction generator. This generator can be applied for slow speed applications without using the gearbox e.g. wind turbine. The generator is multi pole with all of the windings placed on the stator. Rotor is tooth-like and has no windings on it. Primary winding is three phase, secondary winding is one phase. The testing results and practical research are also presented in the paper.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129270990","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}
In this paper, a laboratory experiment was conducted to compare the performance of lightning discharge characteristics of bare conductor (BC) and covered conductor (CC), resulting from very-close lightning strokes to trees. Special attention is paid to the influence of rainfall on the lightning arc characteristics. All the experiments are performed using full-scale configurations. Other factor investigated is the effects of tree-to-line clearance. The studies reveal a substantial amount of new information which is required to fully understand the true behavior of very-close lightning interaction with power conductors in rainfall, which is often the true lightning situation.
{"title":"Influence of rainfall on lightning flashovers from trees to medium voltage bare and covered conductors","authors":"M. Omidiora, M. Lehtonen, P. Hyvonen","doi":"10.1109/PQ.2012.6256235","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256235","url":null,"abstract":"In this paper, a laboratory experiment was conducted to compare the performance of lightning discharge characteristics of bare conductor (BC) and covered conductor (CC), resulting from very-close lightning strokes to trees. Special attention is paid to the influence of rainfall on the lightning arc characteristics. All the experiments are performed using full-scale configurations. Other factor investigated is the effects of tree-to-line clearance. The studies reveal a substantial amount of new information which is required to fully understand the true behavior of very-close lightning interaction with power conductors in rainfall, which is often the true lightning situation.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114228129","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}
V. Bolgov, K. Janson, J. Šklovski, I. Palu, M. Laanetu
There is rapidly increasing wind generation capacity in Estonia. The main wind areas are located near sea coastal line where wind parks can often be connected only to relatively weak medium-voltage distribution power grids. The aim region of investigation was wind-rich Sõrve peninsula of Saaremaa island. The impact of existing wind farms on levels of voltages, losses and consumption has been preliminarily investigated. A way to decrease voltage deviations has been proposed.
{"title":"Wind power generation impact on Sõrve peninsula network operation in Saaremaa","authors":"V. Bolgov, K. Janson, J. Šklovski, I. Palu, M. Laanetu","doi":"10.1109/PQ.2012.6256223","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256223","url":null,"abstract":"There is rapidly increasing wind generation capacity in Estonia. The main wind areas are located near sea coastal line where wind parks can often be connected only to relatively weak medium-voltage distribution power grids. The aim region of investigation was wind-rich Sõrve peninsula of Saaremaa island. The impact of existing wind farms on levels of voltages, losses and consumption has been preliminarily investigated. A way to decrease voltage deviations has been proposed.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125535271","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}
Presented paper is devoted to research circulation current influence on losses in non-uniform network, when ratio of reactance to resistance is not equal for branches. Project Kurzeme Ring aims to improvement of costumer's power supply reliability and changing the transmission network topology. The goal is to consider the problem for non-uniform meshed networks. The projected Kurzeme Ring which is located in west Latvia is under consideration. Considered network consists of 330 kV power line ring which feeds the 110 kV meshed network inside it. In total the scheme includes about 50 branches and 13 loops. Three possible test cases are given for power losses and circulating currents evaluation and analysis.
{"title":"Non-uniformity impact of power losses in Kurzemes ring project case","authors":"J. Survilo, D. Antonovs, E. Biela","doi":"10.1109/PQ.2012.6256217","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256217","url":null,"abstract":"Presented paper is devoted to research circulation current influence on losses in non-uniform network, when ratio of reactance to resistance is not equal for branches. Project Kurzeme Ring aims to improvement of costumer's power supply reliability and changing the transmission network topology. The goal is to consider the problem for non-uniform meshed networks. The projected Kurzeme Ring which is located in west Latvia is under consideration. Considered network consists of 330 kV power line ring which feeds the 110 kV meshed network inside it. In total the scheme includes about 50 branches and 13 loops. Three possible test cases are given for power losses and circulating currents evaluation and analysis.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129849099","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}
The fall-of-potential method is commonly used for grounding measurements. During measurements of extended grounding systems high external influences of the measurement circuit can occur and can lead to measurement errors. Therefore different methods were investigated in the past. In this paper a new one is shown. In fact it is an upgrade of the commonly known beat-frequency method with a combination of a Fourier transform. The new method can avoid the disadvantages of known analysis methods reaching more accurate measurement results — even at environments with high external influences of the measurement circuit. Additional an error estimation of the new method is presented.
{"title":"New optimized analysis method for measuring extended grounding systems","authors":"M. Lindinger, H. Renner, E. Schmautzer","doi":"10.1109/PQ.2012.6256244","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256244","url":null,"abstract":"The fall-of-potential method is commonly used for grounding measurements. During measurements of extended grounding systems high external influences of the measurement circuit can occur and can lead to measurement errors. Therefore different methods were investigated in the past. In this paper a new one is shown. In fact it is an upgrade of the commonly known beat-frequency method with a combination of a Fourier transform. The new method can avoid the disadvantages of known analysis methods reaching more accurate measurement results — even at environments with high external influences of the measurement circuit. Additional an error estimation of the new method is presented.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127207659","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}
Operation of a unidirectional Vienna rectifier is described in the paper using basic electrical circuit laws only without referring to the space vector theory, typically employed in the literature. An average model is derived for a general unbalanced load and classical control theory is employed to construct the control laws for a three-loop control structure. Simulation results are given to validate the presented approach.
{"title":"Modeling and classical control of unidirectional Vienna rectifiers","authors":"S. Gadelovitz, A. Kuperman","doi":"10.1109/PQ.2012.6256206","DOIUrl":"https://doi.org/10.1109/PQ.2012.6256206","url":null,"abstract":"Operation of a unidirectional Vienna rectifier is described in the paper using basic electrical circuit laws only without referring to the space vector theory, typically employed in the literature. An average model is derived for a general unbalanced load and classical control theory is employed to construct the control laws for a three-loop control structure. Simulation results are given to validate the presented approach.","PeriodicalId":185013,"journal":{"name":"2012 Electric Power Quality and Supply Reliability","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134226039","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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