Pub Date : 2009-07-26DOI: 10.1109/PES.2009.5275426
H. Chao, F. Li
Growth in electricity demand with lack of investment in new transmission facilities has led to the formation of load pockets with long congestion hours over transmission bottlenecks. When assessing resource adequacy with reference to the load pockets, one needs to include both generation resources and power delivery systems to capture their impacts on system reliability and market economics at the delivery points. This paper presents a resource adequacy analysis approach to evaluate reliability as well as economic impact in a competitive energy market. Unavailability of generating units and transmission facilities is considered in market simulations to assess the overall adequacy of load-serving ability in a load pocket. Effects of transmission are illustrated through a market simulation analysis of the NYCA system based on publicly available transmission, generation, and demand data.
{"title":"Resource adequacy assessment considering transmission and generation via market simulations","authors":"H. Chao, F. Li","doi":"10.1109/PES.2009.5275426","DOIUrl":"https://doi.org/10.1109/PES.2009.5275426","url":null,"abstract":"Growth in electricity demand with lack of investment in new transmission facilities has led to the formation of load pockets with long congestion hours over transmission bottlenecks. When assessing resource adequacy with reference to the load pockets, one needs to include both generation resources and power delivery systems to capture their impacts on system reliability and market economics at the delivery points. This paper presents a resource adequacy analysis approach to evaluate reliability as well as economic impact in a competitive energy market. Unavailability of generating units and transmission facilities is considered in market simulations to assess the overall adequacy of load-serving ability in a load pocket. Effects of transmission are illustrated through a market simulation analysis of the NYCA system based on publicly available transmission, generation, and demand data.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134609179","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}
M. R. Gouvêa, D. Duarte, J. Lopes, S. Caparroz, I.K. de Lima, A. Suprizzi, L. Goulart
While searching for solutions to minimize environmental impact of substations and improve efficiency in services by optimizing costs, AES Eletropaulo promoted an R&D project to implement smaller substations, which are operationally integrated with feeders and amongst each other, in such a way as to optimize power reserve capacity. ENERQ/USP, ABB and Themag, were invited to take part in this project, thus establishing an attractive partnership in which the utility describes the problem, criticizes alternatives and evaluates application feasibility; the University researches and shapes solution proposals; the Manufacturer develops proposals and equipment and; finally, the designer materializes the solution. This article presents the methodology and the results obtained, and describes solution implementation in a pilot area. Methodology involves an innovative method in the evaluation of substation alternatives, which contemplates objective issues in direct manner, and intangible issues through structured specialist analysis. Analysis of the grid, which functions as "distributed substation" "interconnection bus", allowed for optimum location of re-connectors and maneuver switches, maximizing continuity and operational ease. The pilot project is being implemented in the region of Cotia, Sao Paulo, where strong environmental restrictions prevent penetration of high voltage lines within load center and 34.5 kV power is available at neighboring substations.
{"title":"Distributed substations: an innovative low impact solution","authors":"M. R. Gouvêa, D. Duarte, J. Lopes, S. Caparroz, I.K. de Lima, A. Suprizzi, L. Goulart","doi":"10.1049/CP:20051317","DOIUrl":"https://doi.org/10.1049/CP:20051317","url":null,"abstract":"While searching for solutions to minimize environmental impact of substations and improve efficiency in services by optimizing costs, AES Eletropaulo promoted an R&D project to implement smaller substations, which are operationally integrated with feeders and amongst each other, in such a way as to optimize power reserve capacity. ENERQ/USP, ABB and Themag, were invited to take part in this project, thus establishing an attractive partnership in which the utility describes the problem, criticizes alternatives and evaluates application feasibility; the University researches and shapes solution proposals; the Manufacturer develops proposals and equipment and; finally, the designer materializes the solution. This article presents the methodology and the results obtained, and describes solution implementation in a pilot area. Methodology involves an innovative method in the evaluation of substation alternatives, which contemplates objective issues in direct manner, and intangible issues through structured specialist analysis. Analysis of the grid, which functions as \"distributed substation\" \"interconnection bus\", allowed for optimum location of re-connectors and maneuver switches, maximizing continuity and operational ease. The pilot project is being implemented in the region of Cotia, Sao Paulo, where strong environmental restrictions prevent penetration of high voltage lines within load center and 34.5 kV power is available at neighboring substations.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124380426","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 : 2005-05-31DOI: 10.1109/TDC.2004.1432472
C.A. Silveira, G.M. Fonseca, C. Costa, R. Aquino, L. D. de Medeiros
This paper presents the measurements of electric and magnetic fields in an utility substation in order to attest how electromagnetic couplings may be modified in function of equipments arrangement. The results of these measurements are used to obtain a graphic representation of how the electromagnetic fields are distributed. Aspects from electromagnetic compatibility in substations are presented and the relevance of steady-state fields evaluation stated. This paper also describes aspects of the electromagnetic environment, identifying the best placement of sensitive electronic equipments in order to assure their adequate operation in substations.
{"title":"Analyzing low frequency couplings in substations under steady-state conditions: part I","authors":"C.A. Silveira, G.M. Fonseca, C. Costa, R. Aquino, L. D. de Medeiros","doi":"10.1109/TDC.2004.1432472","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432472","url":null,"abstract":"This paper presents the measurements of electric and magnetic fields in an utility substation in order to attest how electromagnetic couplings may be modified in function of equipments arrangement. The results of these measurements are used to obtain a graphic representation of how the electromagnetic fields are distributed. Aspects from electromagnetic compatibility in substations are presented and the relevance of steady-state fields evaluation stated. This paper also describes aspects of the electromagnetic environment, identifying the best placement of sensitive electronic equipments in order to assure their adequate operation in substations.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117164093","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432427
L.R.S. Colman, P. B. Araujo
This work deals with the effects of the series compensation on the electric power system for small-signal stability studies. Therefore, the system is modeled admitting the existence of the compensation and then, the equations are linearized and a linear model is obtained for a single machine-infinite bus power system with a compensator installed. The resulting model with nine defined constants is very similar to the Heffron & Phillips linear model widely used on the existent literature. Finally, simulations are executed for an example system, to analyze the behavior of these constants when loading the system.
{"title":"Effects of the thyristor controlled series capacitor on the electric power system","authors":"L.R.S. Colman, P. B. Araujo","doi":"10.1109/TDC.2004.1432427","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432427","url":null,"abstract":"This work deals with the effects of the series compensation on the electric power system for small-signal stability studies. Therefore, the system is modeled admitting the existence of the compensation and then, the equations are linearized and a linear model is obtained for a single machine-infinite bus power system with a compensator installed. The resulting model with nine defined constants is very similar to the Heffron & Phillips linear model widely used on the existent literature. Finally, simulations are executed for an example system, to analyze the behavior of these constants when loading the system.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123937068","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432367
R. Pereira, L. da Silva, J. Mantovani
Phasor measurement units (PMUs) optimized allocation allows control, monitoring and accurate operation of electric power distribution systems, improving reliability and service quality. Good quality and considerable results are obtained for transmission systems using fault location techniques based on voltage measurements. Based on these techniques and performing PMUs optimized allocation it is possible to develop an electric power distribution system fault locator, which provides accurate results. The PMUs allocation problem presents combinatorial features related to devices number that can be allocated, and also probably places for allocation. Tabu search algorithm is the proposed technique to carry out PMUs allocation. This technique applied in a 141 buses real-life distribution urban feeder improved significantly the fault location results.
{"title":"PMUs optimized allocation using a tabu search algorithm for fault location in electric power distribution system","authors":"R. Pereira, L. da Silva, J. Mantovani","doi":"10.1109/TDC.2004.1432367","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432367","url":null,"abstract":"Phasor measurement units (PMUs) optimized allocation allows control, monitoring and accurate operation of electric power distribution systems, improving reliability and service quality. Good quality and considerable results are obtained for transmission systems using fault location techniques based on voltage measurements. Based on these techniques and performing PMUs optimized allocation it is possible to develop an electric power distribution system fault locator, which provides accurate results. The PMUs allocation problem presents combinatorial features related to devices number that can be allocated, and also probably places for allocation. Tabu search algorithm is the proposed technique to carry out PMUs allocation. This technique applied in a 141 buses real-life distribution urban feeder improved significantly the fault location results.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114428739","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432453
L. Nepomuceno, P. S. da Silva
The predispatch model (PD) calculates a short-term generation policy for power systems. In this work a PD model is proposed that improves two modeling aspects generally neglected in the literature: voltage/reactive power constraints and ramp rate constraints for generating units. Reactive power constraints turn the PD into a nonlinear problem and the ramp rate constraints couple the problem dynamically in time domain. The solution of the PD is turned into a harder task when such constraints are introduced. The dual decomposition/Lagrangian relaxation technique is used in the solution approach for handing dynamic constraints. As a result the PD is decomposed into a series of independent optimal power flow (FPO) subproblems, in which the reactive power is represented in detail. The solution of the independent FPO is coordinated by means of Lagrange multipliers, so that dynamic constraints are iteratively satisfied. Comparisons between dispatch policies calculated with and without the representation of ramp rate constraints are performed, using the IEEE 30 bus test system. The results point-out the importance of representing such constraints in the generation dispatch policy.
{"title":"An active/reactive predispatch model incorporating ramp rate constraints solved by dual decomposition/Lagrangian relaxation","authors":"L. Nepomuceno, P. S. da Silva","doi":"10.1109/TDC.2004.1432453","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432453","url":null,"abstract":"The predispatch model (PD) calculates a short-term generation policy for power systems. In this work a PD model is proposed that improves two modeling aspects generally neglected in the literature: voltage/reactive power constraints and ramp rate constraints for generating units. Reactive power constraints turn the PD into a nonlinear problem and the ramp rate constraints couple the problem dynamically in time domain. The solution of the PD is turned into a harder task when such constraints are introduced. The dual decomposition/Lagrangian relaxation technique is used in the solution approach for handing dynamic constraints. As a result the PD is decomposed into a series of independent optimal power flow (FPO) subproblems, in which the reactive power is represented in detail. The solution of the independent FPO is coordinated by means of Lagrange multipliers, so that dynamic constraints are iteratively satisfied. Comparisons between dispatch policies calculated with and without the representation of ramp rate constraints are performed, using the IEEE 30 bus test system. The results point-out the importance of representing such constraints in the generation dispatch policy.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126460695","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432375
F.C. Gaino, A. Padilha-Feltrin
This paper presents some initial concepts for including reactive power in linear methods for computing available transfer capability (ATC). It is proposed an approximation for the reactive power flows computation that uses the exact circle equations for the transmission line complex flow, and then it is determined the ATC using active power distribution factors. The transfer capability can be increased using the sensitivities of flow that show the best group of buses which can have their reactive power injection modified in order to remove the overload in the transmission lines. The results of the ATC computation and of the use of the sensitivities of flow are presented using the Cigre 32-bus system.
{"title":"Influence of the supply of reactive power in the calculation of the transfer capability","authors":"F.C. Gaino, A. Padilha-Feltrin","doi":"10.1109/TDC.2004.1432375","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432375","url":null,"abstract":"This paper presents some initial concepts for including reactive power in linear methods for computing available transfer capability (ATC). It is proposed an approximation for the reactive power flows computation that uses the exact circle equations for the transmission line complex flow, and then it is determined the ATC using active power distribution factors. The transfer capability can be increased using the sensitivities of flow that show the best group of buses which can have their reactive power injection modified in order to remove the overload in the transmission lines. The results of the ATC computation and of the use of the sensitivities of flow are presented using the Cigre 32-bus system.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131216437","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432343
F.C.V. Malange, D. Alves, L.C.P. Silva, C. Castro, G. Costa
This paper presents an alternative methodology for loading margin improvement and total real power losses reduction by using a continuation method. In order to attain this goal, a parameterizing equation based on the total real power losses and the equations of the reactive power at the slack and generation buses are added to the conventional power flow equations. The voltages at these buses are considered as control variables and a new parameter is chosen to reduce the real power losses in the transmission lines. The results show that this procedure leads to maximum loading point increase and consequently, in static voltage stability margin improvement. Besides, this procedure also takes to a reduction in the operational costs and, simultaneously, to voltage profile improvement. Another important result of this methodology is that the resulting operating points are close to that provided by an optimal power flow program.
{"title":"Alternative continuation method for loading margin improvement and transmission losses reduction","authors":"F.C.V. Malange, D. Alves, L.C.P. Silva, C. Castro, G. Costa","doi":"10.1109/TDC.2004.1432343","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432343","url":null,"abstract":"This paper presents an alternative methodology for loading margin improvement and total real power losses reduction by using a continuation method. In order to attain this goal, a parameterizing equation based on the total real power losses and the equations of the reactive power at the slack and generation buses are added to the conventional power flow equations. The voltages at these buses are considered as control variables and a new parameter is chosen to reduce the real power losses in the transmission lines. The results show that this procedure leads to maximum loading point increase and consequently, in static voltage stability margin improvement. Besides, this procedure also takes to a reduction in the operational costs and, simultaneously, to voltage profile improvement. Another important result of this methodology is that the resulting operating points are close to that provided by an optimal power flow program.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114974966","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432350
L. da Silva, R. Pereira, J. Mantovani
Reliability of power supply is related, among other factors, to the control and protection devices allocation in feeders of distribution systems. In this way, optimized allocation of sectionalizing switches and protection devices in strategic points of distribution circuits, improves the quality of power supply and the system reliability indices. In this work, it is presented a mixed integer nonlinear programming (MINLP) model, with real and binary variables, for the sectionalizing switches and protection devices allocation problem, in strategic sectors, aimed at improving reliability indices, increasing the utilities billing and fulfilling exigencies of regulatory agencies for the power supply. Optimized allocation of protection devices and switches for restoration, allows that those faulted sectors of the system can be isolated and repaired, re-managing loads of the analyzed feeder into the set of neighbor feeders. Proposed solution technique is a genetic algorithm (GA) developed exploiting the physical characteristics of the problem. Results obtained through simulations for a real-life circuit, are presented.
{"title":"Optimized allocation of sectionalizing switches and control and protection devices for reliability indices improvement in distribution systems","authors":"L. da Silva, R. Pereira, J. Mantovani","doi":"10.1109/TDC.2004.1432350","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432350","url":null,"abstract":"Reliability of power supply is related, among other factors, to the control and protection devices allocation in feeders of distribution systems. In this way, optimized allocation of sectionalizing switches and protection devices in strategic points of distribution circuits, improves the quality of power supply and the system reliability indices. In this work, it is presented a mixed integer nonlinear programming (MINLP) model, with real and binary variables, for the sectionalizing switches and protection devices allocation problem, in strategic sectors, aimed at improving reliability indices, increasing the utilities billing and fulfilling exigencies of regulatory agencies for the power supply. Optimized allocation of protection devices and switches for restoration, allows that those faulted sectors of the system can be isolated and repaired, re-managing loads of the analyzed feeder into the set of neighbor feeders. Proposed solution technique is a genetic algorithm (GA) developed exploiting the physical characteristics of the problem. Results obtained through simulations for a real-life circuit, are presented.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121479767","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 : 2004-12-01DOI: 10.1109/TDC.2004.1432380
D. Lima, A. Padilha-Feltrin
An analysis of the performances of three important methods for generators and loads loss allocation is presented. The discussed methods are: based on pro-rata technique; based on the incremental technique; and based on matrices of circuit. The algorithms are tested considering different generation conditions, using a known electric power system: IEEE 14 bus. Presented and discussed results verify: the location and the magnitude of generators and loads; the possibility to have agents well or poorly located in each network configuration; the discriminatory behavior considering variations in the power flow in the transmission lines.
{"title":"Comparison of algorithms for loss allocation in transmission networks considering power redispatch","authors":"D. Lima, A. Padilha-Feltrin","doi":"10.1109/TDC.2004.1432380","DOIUrl":"https://doi.org/10.1109/TDC.2004.1432380","url":null,"abstract":"An analysis of the performances of three important methods for generators and loads loss allocation is presented. The discussed methods are: based on pro-rata technique; based on the incremental technique; and based on matrices of circuit. The algorithms are tested considering different generation conditions, using a known electric power system: IEEE 14 bus. Presented and discussed results verify: the location and the magnitude of generators and loads; the possibility to have agents well or poorly located in each network configuration; the discriminatory behavior considering variations in the power flow in the transmission lines.","PeriodicalId":126347,"journal":{"name":"2004 IEEE/PES Transmision and Distribution Conference and Exposition: Latin America (IEEE Cat. No. 04EX956)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134413608","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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