Pub Date : 2017-11-01DOI: 10.1109/COBEP.2017.8257256
Rodrigo L. dos Santos, Diogo M. Rufino, Maxwell B. M. de Morais, E. M. Sá
This paper presents the LED driver with power factor correction (PFC) and low current harmonic distortion. The structure provides low current ripple, low percent flicker and zero voltage switching (ZVS). The converter output power is varied by reducing the switching frequency, and it does not use electrolytic capacitors (E-cap), what increase the LED driver lifetime. A prototype was developed to evaluate the performance of the proposal, while results are properly presented and discussed. The experimental results presented power factor is 0.996, 3.19% current total harmonic distortion, 9.5% low frequency current ripple and a percent flicker in accordance with the IEEE Std 1789-2015.
{"title":"A charge-pump led driver with PFC and low-frequency-flicker reduction","authors":"Rodrigo L. dos Santos, Diogo M. Rufino, Maxwell B. M. de Morais, E. M. Sá","doi":"10.1109/COBEP.2017.8257256","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257256","url":null,"abstract":"This paper presents the LED driver with power factor correction (PFC) and low current harmonic distortion. The structure provides low current ripple, low percent flicker and zero voltage switching (ZVS). The converter output power is varied by reducing the switching frequency, and it does not use electrolytic capacitors (E-cap), what increase the LED driver lifetime. A prototype was developed to evaluate the performance of the proposal, while results are properly presented and discussed. The experimental results presented power factor is 0.996, 3.19% current total harmonic distortion, 9.5% low frequency current ripple and a percent flicker in accordance with the IEEE Std 1789-2015.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121215483","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257355
L. S. Pereira, Yury Pontes, Francisco M. P. R. da Costa
This article presents a study carried out in a medium-sized store in the city of Juazeiro do Norte, State of Ceará, where its fluorescent lamps are replaced by Leds. The analysis was performed by comparing yield between the types of lamps and the economy in Kwh generated, savings in real obtained with the substitution, through analyzes and comparisons. Three replacement situations were verified, the first with tubular T5 of 20W and Led of 9W, the second of Tubular T8 of 25W and Led of 10W, the third a general explanation linking the two previous situations to show the total saving of electrical energy Monthly and annual income, respectively. It was also possible to show the cost with energy that each type of lamp generates. According to the data obtained, it is possible to minimize up to 65% of the annual expenses with electricity, obtaining a return of investment of 3.5 months, based on all the studied situations, the study deepens the reduction of electric power for each case, In addition to emphasizing the return on investment and the value that each type of lamp costs.
本文介绍了在塞埃尔州Juazeiro do Norte市的一家中型商店进行的一项研究，该商店的荧光灯被led取代。分析是通过比较不同类型的灯的产量和产生的千瓦时经济，通过分析和比较获得的替代实际节省来进行的。验证了三种替换情况，第一种是管状T5为20W, Led为9W，第二种是管状T8为25W, Led为10W，第三种是将前两种情况联系起来的总述，分别显示每月和每年节省的总电能。还可以用每种类型的灯产生的能量来显示成本。根据所获得的数据，可以最大限度地减少65%的年度费用与电力，获得3.5个月的投资回报，根据所有的研究情况，研究深化了电力的减少，除了强调投资回报和每一种灯的成本价值。
{"title":"Energy efficiency in the replacement of fluorescent lamps by led: Application in a store","authors":"L. S. Pereira, Yury Pontes, Francisco M. P. R. da Costa","doi":"10.1109/COBEP.2017.8257355","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257355","url":null,"abstract":"This article presents a study carried out in a medium-sized store in the city of Juazeiro do Norte, State of Ceará, where its fluorescent lamps are replaced by Leds. The analysis was performed by comparing yield between the types of lamps and the economy in Kwh generated, savings in real obtained with the substitution, through analyzes and comparisons. Three replacement situations were verified, the first with tubular T5 of 20W and Led of 9W, the second of Tubular T8 of 25W and Led of 10W, the third a general explanation linking the two previous situations to show the total saving of electrical energy Monthly and annual income, respectively. It was also possible to show the cost with energy that each type of lamp generates. According to the data obtained, it is possible to minimize up to 65% of the annual expenses with electricity, obtaining a return of investment of 3.5 months, based on all the studied situations, the study deepens the reduction of electric power for each case, In addition to emphasizing the return on investment and the value that each type of lamp costs.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"170 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121343975","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257293
Everton P. Correa, M. Mezaroba, G. Azevedo
This paper present a reduced-order small-signal model of microgrid considering an arbitrary number of parallel-connected inverters. The control technique used for inverters is the control without communication based on frequency and voltage droops. Each element of microgrid is modeled in state-space form and all are combined resulting in a single system. Simutation results are presented to show that the proposed model has good accuracy and also to show that it can be used as tool for stability analysis and adjustment of droop control coefficients of the inverters.
{"title":"Reduced-order model of AC microgrid for stability analysis and adjustment of droop control","authors":"Everton P. Correa, M. Mezaroba, G. Azevedo","doi":"10.1109/COBEP.2017.8257293","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257293","url":null,"abstract":"This paper present a reduced-order small-signal model of microgrid considering an arbitrary number of parallel-connected inverters. The control technique used for inverters is the control without communication based on frequency and voltage droops. Each element of microgrid is modeled in state-space form and all are combined resulting in a single system. Simutation results are presented to show that the proposed model has good accuracy and also to show that it can be used as tool for stability analysis and adjustment of droop control coefficients of the inverters.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129028186","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257341
F. Reis, K.P. Santos, B. C. Torrico, P. Praça, R. Bascopé, T. Neto
The boost converter is a dc-dc power converter which is able to raise the input voltage level to the output load, according to the duty cycle. It is a well-known power converter used in several applications, i.e. power supplies, LED's applications, uninterrupted power system, converters for renewable energies, among others. However, the boost converter small-signal model is a non-minimal phase system, which usually has a undershoot response, a steady-state error, and a slow transient response due to the zero in the right half-plane. Therefore, this paper shows a control technique based on the Filtered Smith Predictor, in order to mitigate the non-minimal phase effect, eliminate the complex poles with low damping factor, increase the relative stability and increase the system's time response. The simulation and experimental results will be presented and discussed. Furthermore, the results will be compared with the conventional PI controller.
{"title":"Filtered smith predictor applied to a boost converter for minimizing the effect of non-minimal phase and rejection of disturbances","authors":"F. Reis, K.P. Santos, B. C. Torrico, P. Praça, R. Bascopé, T. Neto","doi":"10.1109/COBEP.2017.8257341","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257341","url":null,"abstract":"The boost converter is a dc-dc power converter which is able to raise the input voltage level to the output load, according to the duty cycle. It is a well-known power converter used in several applications, i.e. power supplies, LED's applications, uninterrupted power system, converters for renewable energies, among others. However, the boost converter small-signal model is a non-minimal phase system, which usually has a undershoot response, a steady-state error, and a slow transient response due to the zero in the right half-plane. Therefore, this paper shows a control technique based on the Filtered Smith Predictor, in order to mitigate the non-minimal phase effect, eliminate the complex poles with low damping factor, increase the relative stability and increase the system's time response. The simulation and experimental results will be presented and discussed. Furthermore, the results will be compared with the conventional PI controller.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117249236","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257426
Arceu Santos Cordeiro de Campos, A. C. Gomes, A. S. de Morais
Smart DC micro/nanogrids have become the subject of much attention in recent years due to the growing interest in adding renewable energy sources and electric vehicles to residential and small buildings. The multi-bus hybrid microgrid has the potential to feed different loads with more appropriate voltage. This paper presents a new topology of bidirectional Flyback multiple winding converter, which can be used in microgrid systems. The proposed converter can interconnect several DC voltage buses that provide power in all directions. The control technique allows the safe converter' switching and proper power flux control. Operation stages and simulation results of a four winding converter are presented.
{"title":"Multi-winding bidirectional flyback converter","authors":"Arceu Santos Cordeiro de Campos, A. C. Gomes, A. S. de Morais","doi":"10.1109/COBEP.2017.8257426","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257426","url":null,"abstract":"Smart DC micro/nanogrids have become the subject of much attention in recent years due to the growing interest in adding renewable energy sources and electric vehicles to residential and small buildings. The multi-bus hybrid microgrid has the potential to feed different loads with more appropriate voltage. This paper presents a new topology of bidirectional Flyback multiple winding converter, which can be used in microgrid systems. The proposed converter can interconnect several DC voltage buses that provide power in all directions. The control technique allows the safe converter' switching and proper power flux control. Operation stages and simulation results of a four winding converter are presented.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127427141","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257319
L. Bellinaso, M. F. Basquera, R. Vieira, H. Gründling, L. Michels
Dc-dc boost converters have been widely employed at input stage of photovoltaic (PV) inverters. Since PV system dynamic depend on solar irradiance, temperature and operation point of I-V curve, its small-signal models changes significantly. Most applications of this converter apply a bulk input capacitance to reduce the impact of PV module's behavior on control system dynamics. However, conventional approaches cannot achieve fast dynamic response for any operation point using a current control strategy to limit the power processed by the converter. This manuscript proposes a cascaded control structure complying with all these requirements. It is composed of a non-linear current controller and an adaptive voltage controller with fast detection of the system model. Experimental results are carried out to validate the proposed technique.
{"title":"Cascaded MPPT control with adaptive voltage controller applied to boost converters for PV applications","authors":"L. Bellinaso, M. F. Basquera, R. Vieira, H. Gründling, L. Michels","doi":"10.1109/COBEP.2017.8257319","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257319","url":null,"abstract":"Dc-dc boost converters have been widely employed at input stage of photovoltaic (PV) inverters. Since PV system dynamic depend on solar irradiance, temperature and operation point of I-V curve, its small-signal models changes significantly. Most applications of this converter apply a bulk input capacitance to reduce the impact of PV module's behavior on control system dynamics. However, conventional approaches cannot achieve fast dynamic response for any operation point using a current control strategy to limit the power processed by the converter. This manuscript proposes a cascaded control structure complying with all these requirements. It is composed of a non-linear current controller and an adaptive voltage controller with fast detection of the system model. Experimental results are carried out to validate the proposed technique.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"715 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121998645","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257219
H. Sathler, L. H. Sathler, F. L. F. Marcelino, T. R. de Oliveira, S. I. Seleme, P. Garcia
This paper describes a comparative efficiency study of different topologies for the bidirectional grid interface converter (BGIC) for applications in DC microgrids, which manage the power flow between the utility grid and the DC microgrid with the intent to regulate the main DC bus voltage and simultaneously ensure grid code compliance at the point of common coupling. In this area a lot of studies emerged to improve renewable energy integration with electrical grid and increase the entire system efficiency. For efficiency analysis, semiconductors and inductors losses were considered based on datasheets information. MOSFETs usage was considered in order to verify the efficiency increasing against IGBTs for BGIC application.
{"title":"A comparative efficiency study on bidirectional grid interface converters applied to low power DC nanogrids","authors":"H. Sathler, L. H. Sathler, F. L. F. Marcelino, T. R. de Oliveira, S. I. Seleme, P. Garcia","doi":"10.1109/COBEP.2017.8257219","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257219","url":null,"abstract":"This paper describes a comparative efficiency study of different topologies for the bidirectional grid interface converter (BGIC) for applications in DC microgrids, which manage the power flow between the utility grid and the DC microgrid with the intent to regulate the main DC bus voltage and simultaneously ensure grid code compliance at the point of common coupling. In this area a lot of studies emerged to improve renewable energy integration with electrical grid and increase the entire system efficiency. For efficiency analysis, semiconductors and inductors losses were considered based on datasheets information. MOSFETs usage was considered in order to verify the efficiency increasing against IGBTs for BGIC application.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"152 11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125893665","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257428
Maxwell B. M. de Morais, Diogo M. Rufino, Pedro S. B. Ferreira, Rodrigo L. dos Santos, E. M. Sá
This paper presents the evaluation of a single-phase topology and a three-phase topology. Photometric and flicker characteristics were compared. To validate the results, a single-phase charge-pump driver for power LEDs driving a 22 W luminaire, and a three-phase driver with a switched capacitor was used for power LEDs driving a 216 W luminaire. The obtained results were compared with the actual norms. The three-phase driver is operating within the recommended operating region in Std. 1789-2015, while the single-phase driver is operating outside the recommended region.
{"title":"A comparative study the percent flicker and photometric measurement in three-phase and single-phase drivers","authors":"Maxwell B. M. de Morais, Diogo M. Rufino, Pedro S. B. Ferreira, Rodrigo L. dos Santos, E. M. Sá","doi":"10.1109/COBEP.2017.8257428","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257428","url":null,"abstract":"This paper presents the evaluation of a single-phase topology and a three-phase topology. Photometric and flicker characteristics were compared. To validate the results, a single-phase charge-pump driver for power LEDs driving a 22 W luminaire, and a three-phase driver with a switched capacitor was used for power LEDs driving a 216 W luminaire. The obtained results were compared with the actual norms. The three-phase driver is operating within the recommended operating region in Std. 1789-2015, while the single-phase driver is operating outside the recommended region.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124866014","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257239
Paulo Henrique Feretti, F. L. Tofoli
This work presents a buck-boost converter based on the three-state switching cell (3SSC), which has been widely employed in the conception of several converter topologies. The structure is part of family of converters that has been previously reported in literature, even though the detailed study of dc-dc buck-boost-type 3SSC-based converters has not been presented before. Compared to the classical buck-boost converter, prominent advantages can be addressed to the proposed approach e.g. the input current is continuous when the duty cycle is higher than 0.5 and the current stresses through the semiconductor elements are reduced. A qualitative analysis is carried out in overlapping mode, so that the operating stages are analyzed and a design procedure can be obtained. Simulation and experimental results are presented and properly discussed in order to validate the theoretical assumptions.
{"title":"A DC-DC buck-boost converter based on the three-state switching cell","authors":"Paulo Henrique Feretti, F. L. Tofoli","doi":"10.1109/COBEP.2017.8257239","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257239","url":null,"abstract":"This work presents a buck-boost converter based on the three-state switching cell (3SSC), which has been widely employed in the conception of several converter topologies. The structure is part of family of converters that has been previously reported in literature, even though the detailed study of dc-dc buck-boost-type 3SSC-based converters has not been presented before. Compared to the classical buck-boost converter, prominent advantages can be addressed to the proposed approach e.g. the input current is continuous when the duty cycle is higher than 0.5 and the current stresses through the semiconductor elements are reduced. A qualitative analysis is carried out in overlapping mode, so that the operating stages are analyzed and a design procedure can be obtained. Simulation and experimental results are presented and properly discussed in order to validate the theoretical assumptions.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123569575","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 : 2017-11-01DOI: 10.1109/COBEP.2017.8257300
R. A. Torres, E. F. Cota, V. F. Mendes
This paper addresses the use of resonant control to improve the grid ride-through capability of Doubly Fed Induction Generators (DFIG) under unbalanced grid conditions. DFIG is very sensitive to grid disturbances as its stator circuit is directly connected to the grid. Voltage sags can be harmful to the wind energy conversion systems (WECS) as they induce high voltages and high currents in the rotor circuit. It is important that wind energy systems continue operating during grid disturbances in order to guarantee grid stability. Electric system operators worldwide are introducing minimum requirements for the connection of wind energy systems to the grid. In this regard, this paper presents the insertion of resonant control to the classical PI control strategy in order to improve the ride-through capability during unbalanced voltage dips. The study was carried out in a 30kW WECS laboratory bench. Simulation results using MATLAB/Simulink and experimental results show the control performance.
{"title":"Ride-through capability improvement of 30kW DFIG-based wind turbine under unsymmetrical voltage dip","authors":"R. A. Torres, E. F. Cota, V. F. Mendes","doi":"10.1109/COBEP.2017.8257300","DOIUrl":"https://doi.org/10.1109/COBEP.2017.8257300","url":null,"abstract":"This paper addresses the use of resonant control to improve the grid ride-through capability of Doubly Fed Induction Generators (DFIG) under unbalanced grid conditions. DFIG is very sensitive to grid disturbances as its stator circuit is directly connected to the grid. Voltage sags can be harmful to the wind energy conversion systems (WECS) as they induce high voltages and high currents in the rotor circuit. It is important that wind energy systems continue operating during grid disturbances in order to guarantee grid stability. Electric system operators worldwide are introducing minimum requirements for the connection of wind energy systems to the grid. In this regard, this paper presents the insertion of resonant control to the classical PI control strategy in order to improve the ride-through capability during unbalanced voltage dips. The study was carried out in a 30kW WECS laboratory bench. Simulation results using MATLAB/Simulink and experimental results show the control performance.","PeriodicalId":375493,"journal":{"name":"2017 Brazilian Power Electronics Conference (COBEP)","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123818410","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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