Pub Date : 2003-09-23DOI: 10.1109/pesw.1999.747386
A. Nava-Segura, M. Carmona-Hernandez
Summary form only as given. This paper presents a digital simulation of an active filter, in which the instantaneous harmonic and reactive compensating currents are desegregated in their different /spl alpha//spl beta/ space-trajectories, and in their time-domain waveforms of both the abc and the /spl alpha//spl beta/ system of coordinates. Departing from Akagi's generalized instantaneous reactive power theory, a complete analysis is presented, in which the counterharmonic compensating current injected to the coupling point of the AC mains feeding a six-pulse-controlled three phase AC/DC converter is desegregated in its three components, namely: (a) fundamental reactive current; (b) oscillating harmonic reactive current; and (c) oscillating harmonic active current. It is demonstrated, in a selected number of abc and /spl alpha//spl beta/ oscillograms, and current-space-trajectories that the active filter can compensate either separately or jointly the above mentioned currents.
{"title":"A detailed instantaneous harmonic and reactive compensation analysis of three-phase AC/DC converters, in abc and /spl alpha//spl beta/ coordinates","authors":"A. Nava-Segura, M. Carmona-Hernandez","doi":"10.1109/pesw.1999.747386","DOIUrl":"https://doi.org/10.1109/pesw.1999.747386","url":null,"abstract":"Summary form only as given. This paper presents a digital simulation of an active filter, in which the instantaneous harmonic and reactive compensating currents are desegregated in their different /spl alpha//spl beta/ space-trajectories, and in their time-domain waveforms of both the abc and the /spl alpha//spl beta/ system of coordinates. Departing from Akagi's generalized instantaneous reactive power theory, a complete analysis is presented, in which the counterharmonic compensating current injected to the coupling point of the AC mains feeding a six-pulse-controlled three phase AC/DC converter is desegregated in its three components, namely: (a) fundamental reactive current; (b) oscillating harmonic reactive current; and (c) oscillating harmonic active current. It is demonstrated, in a selected number of abc and /spl alpha//spl beta/ oscillograms, and current-space-trajectories that the active filter can compensate either separately or jointly the above mentioned currents.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121738067","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 : 2002-08-06DOI: 10.1109/PESW.1999.747486
M. Ilić
In today's integrated electricity supply industry, transmission is seen as an (economic) complement to generation. The generation of power and the service of moving it from one node of the grid to another are bundled into a single product called electricity. Transmission and generation resources are planned and operated by a same entity. As a result, transmission costs, mainly consisting of investment costs, are considered common costs and are recovered under the current cost-based regulatory structure through a single bundled price of electricity, which is based on average costs. Transmission pricing is not used as an active signal to shape the generation and consumption of electricity. Here, the author describes how, as the industry is moving toward full open access, the role of transmission has to be redefined and he discusses the objectives of power transmission pricing under open access.
{"title":"On the objectives of transmission pricing under open access","authors":"M. Ilić","doi":"10.1109/PESW.1999.747486","DOIUrl":"https://doi.org/10.1109/PESW.1999.747486","url":null,"abstract":"In today's integrated electricity supply industry, transmission is seen as an (economic) complement to generation. The generation of power and the service of moving it from one node of the grid to another are bundled into a single product called electricity. Transmission and generation resources are planned and operated by a same entity. As a result, transmission costs, mainly consisting of investment costs, are considered common costs and are recovered under the current cost-based regulatory structure through a single bundled price of electricity, which is based on average costs. Transmission pricing is not used as an active signal to shape the generation and consumption of electricity. Here, the author describes how, as the industry is moving toward full open access, the role of transmission has to be redefined and he discusses the objectives of power transmission pricing under open access.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"234 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122832144","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 : 1999-12-01DOI: 10.1109/PESW.1999.747290
J. Cohen, F. de León, L. Hernandez
Summary form only given as follows. This paper presents a time domain model for the representation of powers in linear and nonlinear electrical circuits. The model can account, in a physical (or engineering) sense, for "active and reactive powers" as functions of time. The model is based on the time domain decomposition of the instantaneous power p(t) into two components: p(t)=a(t)+r(t). Where, a(t) represents the instantaneous power consumed by the (linear or nonlinear) load. The information regarding the store/restore process is contained in r(t). In contrast with the traditional frequency domain model in which powers are defined orthogonal (i.e. S/sup 2/=P/sup 2/+Q/sup 2/+D/sup 2/+...) and therefore they do not interact with each other, the proposed model permits the interaction of active and reactive powers at every instant. Using the model of the paper we can obtain the instantaneous power needed for compensation of both wave shape and power factor.
{"title":"Physical time domain representation of powers in linear and nonlinear electrical circuits","authors":"J. Cohen, F. de León, L. Hernandez","doi":"10.1109/PESW.1999.747290","DOIUrl":"https://doi.org/10.1109/PESW.1999.747290","url":null,"abstract":"Summary form only given as follows. This paper presents a time domain model for the representation of powers in linear and nonlinear electrical circuits. The model can account, in a physical (or engineering) sense, for \"active and reactive powers\" as functions of time. The model is based on the time domain decomposition of the instantaneous power p(t) into two components: p(t)=a(t)+r(t). Where, a(t) represents the instantaneous power consumed by the (linear or nonlinear) load. The information regarding the store/restore process is contained in r(t). In contrast with the traditional frequency domain model in which powers are defined orthogonal (i.e. S/sup 2/=P/sup 2/+Q/sup 2/+D/sup 2/+...) and therefore they do not interact with each other, the proposed model permits the interaction of active and reactive powers at every instant. Using the model of the paper we can obtain the instantaneous power needed for compensation of both wave shape and power factor.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134533374","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 : 1999-11-01DOI: 10.1109/PESW.1999.747536
Y. Moon, B. Cho, Tae-Hoon Rho, Byoung-Kon Choi
This paper shows that a well-defined energy function can be developed to reflect the transfer conductances for multi-machine power systems under an assumption that all transmission lines have uniform R/X ratios. The energy function is derived by introducing a pure reactive equivalent system for the given system. In this study, a static energy function reflecting transfer conductances is also derived as well as the transient energy function. The proposed static energy function is applied to voltage stability analysis and tested for various sample systems. The test results show that the accuracy of voltage stability analysis can be considerably improved by reflecting transfer conductances into the energy function.
{"title":"The development of equivalent system technique for deriving an energy function reflecting transfer conductances","authors":"Y. Moon, B. Cho, Tae-Hoon Rho, Byoung-Kon Choi","doi":"10.1109/PESW.1999.747536","DOIUrl":"https://doi.org/10.1109/PESW.1999.747536","url":null,"abstract":"This paper shows that a well-defined energy function can be developed to reflect the transfer conductances for multi-machine power systems under an assumption that all transmission lines have uniform R/X ratios. The energy function is derived by introducing a pure reactive equivalent system for the given system. In this study, a static energy function reflecting transfer conductances is also derived as well as the transient energy function. The proposed static energy function is applied to voltage stability analysis and tested for various sample systems. The test results show that the accuracy of voltage stability analysis can be considerably improved by reflecting transfer conductances into the energy function.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116961319","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 : 1999-11-01DOI: 10.1109/PESW.1999.747284
M.W. Davis, A. H. Gifford, T. Krupa
Summary form only given as follows. Most distributed self-generation operates base loaded and in parallel with the electric utility system (1) to minimize peak loads, (2) to improve reliability, (3) to eliminate the need for reserve margin (standby) and (4) may or may not sell back excess generation. This paper examines the economics of distributed microturbine generation operating isolated from the electric utility system and having enough reserve margin to either match or improve the existing reliability of service provided by central station generation and the T&D system. This analysis shows the isolated operation of microturbines with a reserve margin can provide the same or a higher level of reliability as the electric utility, yet the costs can be lower. Sensitivity analysis for different investment costs, O and M costs, fuel costs, reliability, load shapes (load factors), and alternative fuels were performed and the economic comparisons are made in terms of /spl nsub//kWh. This analysis shows a strong economic preference in applying microturbines to high load factor commercial loads. The cost of standby (from the utility) was found to be from 0.52 to 1.09 c/kWh greater than if the microturbine generation provided its own standby through a built-in reserve margin.
{"title":"Microturbines-an economic and reliability evaluation for commercial, residential, and remote load applications","authors":"M.W. Davis, A. H. Gifford, T. Krupa","doi":"10.1109/PESW.1999.747284","DOIUrl":"https://doi.org/10.1109/PESW.1999.747284","url":null,"abstract":"Summary form only given as follows. Most distributed self-generation operates base loaded and in parallel with the electric utility system (1) to minimize peak loads, (2) to improve reliability, (3) to eliminate the need for reserve margin (standby) and (4) may or may not sell back excess generation. This paper examines the economics of distributed microturbine generation operating isolated from the electric utility system and having enough reserve margin to either match or improve the existing reliability of service provided by central station generation and the T&D system. This analysis shows the isolated operation of microturbines with a reserve margin can provide the same or a higher level of reliability as the electric utility, yet the costs can be lower. Sensitivity analysis for different investment costs, O and M costs, fuel costs, reliability, load shapes (load factors), and alternative fuels were performed and the economic comparisons are made in terms of /spl nsub//kWh. This analysis shows a strong economic preference in applying microturbines to high load factor commercial loads. The cost of standby (from the utility) was found to be from 0.52 to 1.09 c/kWh greater than if the microturbine generation provided its own standby through a built-in reserve margin.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130604610","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 : 1999-10-01DOI: 10.1109/PESW.1999.747344
MoisCs G 6 mez-Morante, D. Nicoletti
Summary form only given as follows. Transformer inrush currents were traditionally evaluated by means of Fourier analysis. Such an approach affects the design of transformer differential relays concerning their immunity to inrush currents. This paper presents a wavelet-based method, which seems to provide a reliable and computationally efficient tool for distinguishing between internal faults and inrush currents.
{"title":"A wavelet-based differential transformer protection","authors":"MoisCs G 6 mez-Morante, D. Nicoletti","doi":"10.1109/PESW.1999.747344","DOIUrl":"https://doi.org/10.1109/PESW.1999.747344","url":null,"abstract":"Summary form only given as follows. Transformer inrush currents were traditionally evaluated by means of Fourier analysis. Such an approach affects the design of transformer differential relays concerning their immunity to inrush currents. This paper presents a wavelet-based method, which seems to provide a reliable and computationally efficient tool for distinguishing between internal faults and inrush currents.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116765536","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 : 1999-10-01DOI: 10.1109/PESW.1999.747303
R. Aggarwal, Q. Xuan, R. Dunn, A. Johns, A. Bennett
Summary form only as given. The work described in this paper addresses the problems encountered by conventional techniques in fault type classification in double-circuit transmission lines; these arise principally due to the mutual coupling between the two circuits under fault conditions, and this mutual coupling is highly variable in nature. It is shown that a neural network based on a combined unsupervised/supervised training methodology provides the ability to accurately classify the fault type by identifying different patterns of the associated voltages and currents. The technique is compared with that based solely on a supervised training algorithm (i.e., bad-propagation network classifier). It is then tested under differed fault types, location resistance and inception angle; different source capacities and load angles are also considered. All the test results show that the proposed fault classifier is very well suited for classifying fault types in double-circuit lines.
{"title":"A novel fault classification technique for double-circuit lines based on a combined unsupervised/supervised neural network","authors":"R. Aggarwal, Q. Xuan, R. Dunn, A. Johns, A. Bennett","doi":"10.1109/PESW.1999.747303","DOIUrl":"https://doi.org/10.1109/PESW.1999.747303","url":null,"abstract":"Summary form only as given. The work described in this paper addresses the problems encountered by conventional techniques in fault type classification in double-circuit transmission lines; these arise principally due to the mutual coupling between the two circuits under fault conditions, and this mutual coupling is highly variable in nature. It is shown that a neural network based on a combined unsupervised/supervised training methodology provides the ability to accurately classify the fault type by identifying different patterns of the associated voltages and currents. The technique is compared with that based solely on a supervised training algorithm (i.e., bad-propagation network classifier). It is then tested under differed fault types, location resistance and inception angle; different source capacities and load angles are also considered. All the test results show that the proposed fault classifier is very well suited for classifying fault types in double-circuit lines.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127190158","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 : 1999-10-01DOI: 10.1109/PESW.1999.747373
D. Lee Hau Aik, G. Andersson
Summary form only as given. Common industry practice assumes certain quasistatic conditions to determine the power stability of HVDC systems. Particularly, a constant Thevenin AC voltage source has become a de facto industry assumption. This work presents a dynamic approach to study the power stability of HVDC power systems. Based on this approach, the impact of dynamic system modelling on the power stability limit of HVDC systems is examined. Consequently this provides an insight into whether the quasistatic assumptions are justified. The qualitative and quantitative impact of system dynamics and associated parameters, respectively, on the quasi-static maximum power curve are shown. These are shown using dynamic time-simulations and mathematical analysis, the close correspondence between their results also mutually verify the two approaches.
{"title":"Impact of dynamic system modelling on the power stability of HVDC systems","authors":"D. Lee Hau Aik, G. Andersson","doi":"10.1109/PESW.1999.747373","DOIUrl":"https://doi.org/10.1109/PESW.1999.747373","url":null,"abstract":"Summary form only as given. Common industry practice assumes certain quasistatic conditions to determine the power stability of HVDC systems. Particularly, a constant Thevenin AC voltage source has become a de facto industry assumption. This work presents a dynamic approach to study the power stability of HVDC power systems. Based on this approach, the impact of dynamic system modelling on the power stability limit of HVDC systems is examined. Consequently this provides an insight into whether the quasistatic assumptions are justified. The qualitative and quantitative impact of system dynamics and associated parameters, respectively, on the quasi-static maximum power curve are shown. These are shown using dynamic time-simulations and mathematical analysis, the close correspondence between their results also mutually verify the two approaches.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"1990 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125504039","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 : 1999-10-01DOI: 10.1109/PESW.1999.747382
B. Clairmont, R. Lordan
Summary form only as given. This paper presents a new technique for calculating the magnetic field shielding effectiveness of thin conductive sheets of materials. The sheets are modeled as meshes of passive shielding wire filaments. Using this technique, complex three dimensional sources and shield configurations can be easily modeled. A computer program was developed to perform the calculations, and a comprehensive set of experiments was performed to verify the technique. Calculations and measurements are compared in the paper. The calculation method provides a numerical and experimentally verified technique for evaluating the shielding effectiveness of thin conductive sheets for power system magnetic field shielding applications. A predictive method such as this is becoming increasingly important as conductive materials are increasingly becoming accepted as effective shielding materials.
{"title":"3-D modeling of thin conductive sheets for magnetic field shielding: calculations and measurements","authors":"B. Clairmont, R. Lordan","doi":"10.1109/PESW.1999.747382","DOIUrl":"https://doi.org/10.1109/PESW.1999.747382","url":null,"abstract":"Summary form only as given. This paper presents a new technique for calculating the magnetic field shielding effectiveness of thin conductive sheets of materials. The sheets are modeled as meshes of passive shielding wire filaments. Using this technique, complex three dimensional sources and shield configurations can be easily modeled. A computer program was developed to perform the calculations, and a comprehensive set of experiments was performed to verify the technique. Calculations and measurements are compared in the paper. The calculation method provides a numerical and experimentally verified technique for evaluating the shielding effectiveness of thin conductive sheets for power system magnetic field shielding applications. A predictive method such as this is becoming increasingly important as conductive materials are increasingly becoming accepted as effective shielding materials.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134492970","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 : 1999-10-01DOI: 10.1109/PESW.1999.747345
T. Leibfried, K. Feser
Summary form only given as follows. The transfer function concept is well known as an additional method of evaluating the impulse test of power transformers in the test laboratory. Another application for this method is monitoring of power transformers in service. According to the method of how to measure transient signals for the calculation of transfer functions, two kinds of monitoring can be distinguished: off-line and on-line monitoring. Both kinds of monitoring as well as their influencing factors are discussed with on-site measurements on power transformers in service.
{"title":"Monitoring of power transformers using the transfer function method","authors":"T. Leibfried, K. Feser","doi":"10.1109/PESW.1999.747345","DOIUrl":"https://doi.org/10.1109/PESW.1999.747345","url":null,"abstract":"Summary form only given as follows. The transfer function concept is well known as an additional method of evaluating the impulse test of power transformers in the test laboratory. Another application for this method is monitoring of power transformers in service. According to the method of how to measure transient signals for the calculation of transfer functions, two kinds of monitoring can be distinguished: off-line and on-line monitoring. Both kinds of monitoring as well as their influencing factors are discussed with on-site measurements on power transformers in service.","PeriodicalId":238503,"journal":{"name":"IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233)","volume":"157 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133287004","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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