Pub Date : 2011-10-01DOI: 10.1109/EPQU.2011.6128804
A. Broy, C. Sourkounis
Electrical or hybrid powered vehicles become a serious alternative to conventional-driven vehicles also for private users. In electric vehicles, the batterie capacities reached an acceptable level and the requirements for a short charging time will rise continually. Actual electric vehicles have charging capacities up to 50 kW, taken from the urban grid. This paper deals with the impact of (high-power) charging electric vehicles on the urban distribution grid.
{"title":"Influence of charging electric vehicles and on the quality of the distribution grids","authors":"A. Broy, C. Sourkounis","doi":"10.1109/EPQU.2011.6128804","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128804","url":null,"abstract":"Electrical or hybrid powered vehicles become a serious alternative to conventional-driven vehicles also for private users. In electric vehicles, the batterie capacities reached an acceptable level and the requirements for a short charging time will rise continually. Actual electric vehicles have charging capacities up to 50 kW, taken from the urban grid. This paper deals with the impact of (high-power) charging electric vehicles on the urban distribution grid.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128202145","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128879
G. Buldu, H. Canbolat, M. Tutar, Mounira Ali
The objective of this paper is to present initial numerical test results for design and analysis of a new small scale self-excited induction generator (SEIG) for a newly designed sea wave energy converter (SWEC) device in the Mediterranean Sea to achieve a high efficiency and power quality. A two dimensional finite element analysis (2D-FEA) is used for numerical computations to consider flux density and circuit parameters of the SEIG for design purpose. This application takes into account the currents induced in the conducting regions (eddy currents) and the electric circuit associated to the SWEC device. The electromagnetic model described by a combined field and circuit equation model is used to perform the simulations and is solved in a finite element environment. The present results demonstrate that the suggested numerical approaches can be some guidelines for development of small wave energy induction generators for effective electricity generation.
{"title":"A study analysis for a self excited induction generator for a sea wave energy extraction application","authors":"G. Buldu, H. Canbolat, M. Tutar, Mounira Ali","doi":"10.1109/EPQU.2011.6128879","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128879","url":null,"abstract":"The objective of this paper is to present initial numerical test results for design and analysis of a new small scale self-excited induction generator (SEIG) for a newly designed sea wave energy converter (SWEC) device in the Mediterranean Sea to achieve a high efficiency and power quality. A two dimensional finite element analysis (2D-FEA) is used for numerical computations to consider flux density and circuit parameters of the SEIG for design purpose. This application takes into account the currents induced in the conducting regions (eddy currents) and the electric circuit associated to the SWEC device. The electromagnetic model described by a combined field and circuit equation model is used to perform the simulations and is solved in a finite element environment. The present results demonstrate that the suggested numerical approaches can be some guidelines for development of small wave energy induction generators for effective electricity generation.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130697921","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128951
H. Khalid, G. M. Bhutto, M. Bongiorno
The Dynamic Voltage Restorer (DVR) is a custom power device that is mainly used for mitigation of voltage sags. The aim of this paper is to investigate and compare different control techniques for this device. In particular, the main focus of the paper is on optimal use of the energy storage. First, the adopted control structure for the DVR will be presented. Then, different strategies for voltage sag mitigation will be described. Among all, the Energy Optimized Compensation (EOC) method will be investigated in detail. Simulation results of EOC method will be presented. Finally the comparison between the EOC and other methods will be shown.
{"title":"On optimal use of energy storage for series connected voltage source converters","authors":"H. Khalid, G. M. Bhutto, M. Bongiorno","doi":"10.1109/EPQU.2011.6128951","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128951","url":null,"abstract":"The Dynamic Voltage Restorer (DVR) is a custom power device that is mainly used for mitigation of voltage sags. The aim of this paper is to investigate and compare different control techniques for this device. In particular, the main focus of the paper is on optimal use of the energy storage. First, the adopted control structure for the DVR will be presented. Then, different strategies for voltage sag mitigation will be described. Among all, the Energy Optimized Compensation (EOC) method will be investigated in detail. Simulation results of EOC method will be presented. Finally the comparison between the EOC and other methods will be shown.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125391921","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128937
Abdulla Al Aghbari, M. A. Neaimi, Muhannad Ashaar
This paper illustrates the main factors that affect the utilization of Distribution Network in Dubai. In addition, it demonstrates DEWA's experience in enhancing the utilization, actions to overcome some technical limitations and real measurements of variables that can affect the utilization. The technical illustration can be considered as a real good model for Gulf Cooperation Council Countries (GCC) since the environmental conditions are very similar to Dubai's case.
{"title":"Study the opportunities of enhancing the utilization of Distribution Network in Dubai","authors":"Abdulla Al Aghbari, M. A. Neaimi, Muhannad Ashaar","doi":"10.1109/EPQU.2011.6128937","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128937","url":null,"abstract":"This paper illustrates the main factors that affect the utilization of Distribution Network in Dubai. In addition, it demonstrates DEWA's experience in enhancing the utilization, actions to overcome some technical limitations and real measurements of variables that can affect the utilization. The technical illustration can be considered as a real good model for Gulf Cooperation Council Countries (GCC) since the environmental conditions are very similar to Dubai's case.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127572565","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128803
E. Lazarevska, Jovan Trpovski
Solar radiation data are essential for most solar energy research and applications. However, the only measurements of solar radiation for which long-term records are available from a large number of locations are the measurements of the global solar radiation. Thus the diffuse solar radiation and the direct solar radiation must be estimated by various means from the global solar radiation. Although a number of diffuse radiation models are available nowadays, they have many drawbacks such as their dependence on geographic location, the type of data, weather conditions etc. The paper presents a different approach to modeling the diffuse solar radiation from the approaches presented in literature which is based both on fuzzy logic and artificial neural network techniques. The adopted neuro-fuzzy model employs a fuzzy inference system with the same structure as that of a Takagi-Sugeno fuzzy model but with a neural network learning mechanism called relevance vector machine. The number of fuzzy rules and parameter values of membership functions of the model are automatically generated through the relevance vector machine. The performance of the model is tested against independent measurement data and is compared to the performance of other models reported in literature. The obtained results show great effectiveness of the adopted neuro-fuzzy model, its main features being the small model dimension (fewer fuzzy rules) and a very good generalization.
{"title":"A neuro-fuzzy model of the solar diffuse radiation with relevance vector machine","authors":"E. Lazarevska, Jovan Trpovski","doi":"10.1109/EPQU.2011.6128803","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128803","url":null,"abstract":"Solar radiation data are essential for most solar energy research and applications. However, the only measurements of solar radiation for which long-term records are available from a large number of locations are the measurements of the global solar radiation. Thus the diffuse solar radiation and the direct solar radiation must be estimated by various means from the global solar radiation. Although a number of diffuse radiation models are available nowadays, they have many drawbacks such as their dependence on geographic location, the type of data, weather conditions etc. The paper presents a different approach to modeling the diffuse solar radiation from the approaches presented in literature which is based both on fuzzy logic and artificial neural network techniques. The adopted neuro-fuzzy model employs a fuzzy inference system with the same structure as that of a Takagi-Sugeno fuzzy model but with a neural network learning mechanism called relevance vector machine. The number of fuzzy rules and parameter values of membership functions of the model are automatically generated through the relevance vector machine. The performance of the model is tested against independent measurement data and is compared to the performance of other models reported in literature. The obtained results show great effectiveness of the adopted neuro-fuzzy model, its main features being the small model dimension (fewer fuzzy rules) and a very good generalization.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129841016","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128880
A. Sattar, A. Al‐Durra, S. Muyeen
This paper concentrates on design and analysis of STATCOM connected at the wind farm terminal in real time environment using Real Time Digital Simulator (RTDS). This work is a part of power hardware-in-loop (PHIL) test required in a future project, and therefore, individual components are models in such a way that is close to real system. For the sake of detail analyses and future study, the system is simulated in two ways. First method is a dual time step approach, where wind turbines and generators of a wind farm, power grid, and control system are realized in the large time-step main network, however, 2-level voltage source converter based STATCOM is modeled in RTDS small time-step environment to adapt with higher switching frequency, where interface transformer is used to link the different time step sub-networks. In the second method, the entire system including the STATCOM is simulated in large time step. Detailed switching scheme for STATCOM and control strategy for both methods are discussed. An option for integrating anemometer for dynamic characteristics analysis is kept open, difficulties of STATCOM switching schemes for control prototype and PHIL testing in RTDS environment are discussed. The merits and demerits of both methods are also presented which is one of the salient features of this study. Results of RTDS are compared with Laboratory standard power system software PSCAD/EMTDC and the features of using RTDS in dynamic characteristics analyses of wind farm are also discussed.
{"title":"Dynamic characteristics analysis of wind farm integrated with STATCOM using RTDS","authors":"A. Sattar, A. Al‐Durra, S. Muyeen","doi":"10.1109/EPQU.2011.6128880","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128880","url":null,"abstract":"This paper concentrates on design and analysis of STATCOM connected at the wind farm terminal in real time environment using Real Time Digital Simulator (RTDS). This work is a part of power hardware-in-loop (PHIL) test required in a future project, and therefore, individual components are models in such a way that is close to real system. For the sake of detail analyses and future study, the system is simulated in two ways. First method is a dual time step approach, where wind turbines and generators of a wind farm, power grid, and control system are realized in the large time-step main network, however, 2-level voltage source converter based STATCOM is modeled in RTDS small time-step environment to adapt with higher switching frequency, where interface transformer is used to link the different time step sub-networks. In the second method, the entire system including the STATCOM is simulated in large time step. Detailed switching scheme for STATCOM and control strategy for both methods are discussed. An option for integrating anemometer for dynamic characteristics analysis is kept open, difficulties of STATCOM switching schemes for control prototype and PHIL testing in RTDS environment are discussed. The merits and demerits of both methods are also presented which is one of the salient features of this study. Results of RTDS are compared with Laboratory standard power system software PSCAD/EMTDC and the features of using RTDS in dynamic characteristics analyses of wind farm are also discussed.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124597910","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128948
K. A. Jaafari, M. Poshtan, A. R. Beig
Nonlinear loads such as variable speed drives constitute bulk of the load on power systems in oil and gas industry. These nonlinear loads are main sources of harmonics and responsible for most of the power quality problems. The passive filters have definite advantage over active filters in terms of components count, cost and reliability. Reliability and maintenance is a serious issue in drilling rigs which are located in offshore and on shore with extreme operating conditions. The passive wide spectrum filters are becoming increasingly popular in these applications and found to overcome some of the limitations of conventional tuned passive filter. This paper gives a complete analysis of wide spectrum passive filters, effect of load and source inductance on its characteristics. The analysis is supported with the simulation results and is being verified experimentally. The analysis given in this paper will be useful for the selection of proper wide spectrum filter for these applications.
{"title":"Passive wide spectrum filter for variable speed drives in oil and gas industry","authors":"K. A. Jaafari, M. Poshtan, A. R. Beig","doi":"10.1109/EPQU.2011.6128948","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128948","url":null,"abstract":"Nonlinear loads such as variable speed drives constitute bulk of the load on power systems in oil and gas industry. These nonlinear loads are main sources of harmonics and responsible for most of the power quality problems. The passive filters have definite advantage over active filters in terms of components count, cost and reliability. Reliability and maintenance is a serious issue in drilling rigs which are located in offshore and on shore with extreme operating conditions. The passive wide spectrum filters are becoming increasingly popular in these applications and found to overcome some of the limitations of conventional tuned passive filter. This paper gives a complete analysis of wide spectrum passive filters, effect of load and source inductance on its characteristics. The analysis is supported with the simulation results and is being verified experimentally. The analysis given in this paper will be useful for the selection of proper wide spectrum filter for these applications.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116596497","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128824
P. Nicolae, D. Stănescu, M. Nicolae, I. Bojoi
The paper deals with specific matters related to the designing, simulation, realization and testing of conditioning boards used for signals of current used to test the control part of power converters using DSP (Digital Signal Processors) and dSPACE. The electric schema is described along with the algorithms used for the designing of the blocks used during circuits' realization. In the final part one presents the experimental waveforms. A comparison is made with the simulated waveforms obtained with dedicated software packages.
本文论述了利用DSP (Digital Signal processor)和dSPACE测试电源变换器控制部分的电流信号调理板的设计、仿真、实现和测试的具体问题。描述了电气原理图以及电路实现过程中所使用的模块设计算法。最后一部分给出了实验波形。并与用专用软件包模拟得到的波形进行了比较。
{"title":"Considerations on signals conditioning circuits","authors":"P. Nicolae, D. Stănescu, M. Nicolae, I. Bojoi","doi":"10.1109/EPQU.2011.6128824","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128824","url":null,"abstract":"The paper deals with specific matters related to the designing, simulation, realization and testing of conditioning boards used for signals of current used to test the control part of power converters using DSP (Digital Signal Processors) and dSPACE. The electric schema is described along with the algorithms used for the designing of the blocks used during circuits' realization. In the final part one presents the experimental waveforms. A comparison is made with the simulated waveforms obtained with dedicated software packages.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122564736","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128914
Yushan Liu, B. Ge, F. Ferreira, A. D. de Almeida, H. Abu-Rub
In today's renewable energy power generation systems, inverters have become key devices connected between energy sources and power grids. The newly presented quasi-Z-source inverter (qZSI) has the unique advantages of boosting DC bus voltage without additional boost link, lower component ratings, as well as constant DC input current compared with the traditional Z-source inverter. To better design the control schemes of this novel topology, the small-signal model is deduced using state variables perturbance mathematical analysis. By this model, the voltage-current closed-loop control of shoot-through duty cycle is designed. The space vector PWM (SVPWM) technique is modified to satisfy the particularity of qZSI. Simulation results certify the correctness and effectiveness of the proposed model and control strategies and demonstrate the applicability of qZSI technology to overcome the disturbances from DC link or AC loads in renewable energy power generation systems.
{"title":"Modeling and SVPWM control of quasi-Z-source inverter","authors":"Yushan Liu, B. Ge, F. Ferreira, A. D. de Almeida, H. Abu-Rub","doi":"10.1109/EPQU.2011.6128914","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128914","url":null,"abstract":"In today's renewable energy power generation systems, inverters have become key devices connected between energy sources and power grids. The newly presented quasi-Z-source inverter (qZSI) has the unique advantages of boosting DC bus voltage without additional boost link, lower component ratings, as well as constant DC input current compared with the traditional Z-source inverter. To better design the control schemes of this novel topology, the small-signal model is deduced using state variables perturbance mathematical analysis. By this model, the voltage-current closed-loop control of shoot-through duty cycle is designed. The space vector PWM (SVPWM) technique is modified to satisfy the particularity of qZSI. Simulation results certify the correctness and effectiveness of the proposed model and control strategies and demonstrate the applicability of qZSI technology to overcome the disturbances from DC link or AC loads in renewable energy power generation systems.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133799088","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 : 2011-10-01DOI: 10.1109/EPQU.2011.6128906
L. Daloub
Electric load of hospitals and medical centers draws reactive power from supply sources resulting in low power factor operating condition. Depending on the load type and patterns, various compensating strategies can be used to correct and counteract rapid variations. Voltage Sourced Static Synchronous VAR Compensators (SVC) doesn't depend on passive components for reactive power control since it uses electronic circuits to create lead or lag angles between applied voltage and injected current into the network to generate capacitive or absorbs inductive (Reactive Power). This practice became a state-of-art technology in reactive power control systems combining both, power and control engineering, to respond to dynamic system variations in milliseconds. The paper clearly address an existing problem of power quality and presents a model of distribution system in 480 bed hospital context using measured values explored through simulation. It uses SVC for voltage stabilizing and improving of power factor in general hospital with steady state condition.
{"title":"Power quality optimization and reactive power control by modeling of SVC in healthcare centre","authors":"L. Daloub","doi":"10.1109/EPQU.2011.6128906","DOIUrl":"https://doi.org/10.1109/EPQU.2011.6128906","url":null,"abstract":"Electric load of hospitals and medical centers draws reactive power from supply sources resulting in low power factor operating condition. Depending on the load type and patterns, various compensating strategies can be used to correct and counteract rapid variations. Voltage Sourced Static Synchronous VAR Compensators (SVC) doesn't depend on passive components for reactive power control since it uses electronic circuits to create lead or lag angles between applied voltage and injected current into the network to generate capacitive or absorbs inductive (Reactive Power). This practice became a state-of-art technology in reactive power control systems combining both, power and control engineering, to respond to dynamic system variations in milliseconds. The paper clearly address an existing problem of power quality and presents a model of distribution system in 480 bed hospital context using measured values explored through simulation. It uses SVC for voltage stabilizing and improving of power factor in general hospital with steady state condition.","PeriodicalId":369941,"journal":{"name":"11th International Conference on Electrical Power Quality and Utilisation","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134256045","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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