Pub Date : 2012-12-31DOI: 10.1109/UPEC.2012.6398608
F. Solomonesc, R. Teslovan, C. Barbulescu, S. Kilyeni, Petru Dan Cristian
There is a growing interest in finding new ways to solve power systems related problems. Heuristic search methods are considered a good alternative to conventional ones. The present work focuses on genetic algorithms (GA). A GA adapted for power flow solving is detailed. Some practical issues are presented.
{"title":"Genetic algorithm power flow computing approach","authors":"F. Solomonesc, R. Teslovan, C. Barbulescu, S. Kilyeni, Petru Dan Cristian","doi":"10.1109/UPEC.2012.6398608","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398608","url":null,"abstract":"There is a growing interest in finding new ways to solve power systems related problems. Heuristic search methods are considered a good alternative to conventional ones. The present work focuses on genetic algorithms (GA). A GA adapted for power flow solving is detailed. Some practical issues are presented.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115787595","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398685
S. Armstrong, D. Mollaghan, A. Blavette, D. O'Sullivan
Environmental concerns, coupled with dwindling fossil fuel supplies, and growing government support, have resulted in increasing amounts of electricity generated from renewable energy. As the number of these installations rise, their influence on the behaviour of the electrical power system becomes more apparent. Transmission System Operators (TSO) carry out power system dynamic simulations in order to investigate the effect of renewable energy systems on the stability and reliability of the grid under varying operating conditions. Correct initialisation is an essential step in the dynamic model. This paper describes a three step methodology for correct initialisation of power systems dynamic model for an ocean energy system. The methodology is validated using DIgSILENT Power Factory simulations.
对环境的担忧，再加上化石燃料供应的减少，以及政府越来越多的支持，导致了可再生能源发电量的增加。随着这些装置数量的增加，它们对电力系统行为的影响变得更加明显。输电系统运营商(TSO)对电力系统进行动态仿真，以研究可再生能源系统在不同运行条件下对电网稳定性和可靠性的影响。正确的初始化是动态模型中必不可少的一步。本文介绍了海洋能源系统动力系统动力学模型正确初始化的三步法。该方法通过DIgSILENT Power Factory仿真得到验证。
{"title":"An initialisation methodology for ocean energy converter dynamic models in power system simulation tools","authors":"S. Armstrong, D. Mollaghan, A. Blavette, D. O'Sullivan","doi":"10.1109/UPEC.2012.6398685","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398685","url":null,"abstract":"Environmental concerns, coupled with dwindling fossil fuel supplies, and growing government support, have resulted in increasing amounts of electricity generated from renewable energy. As the number of these installations rise, their influence on the behaviour of the electrical power system becomes more apparent. Transmission System Operators (TSO) carry out power system dynamic simulations in order to investigate the effect of renewable energy systems on the stability and reliability of the grid under varying operating conditions. Correct initialisation is an essential step in the dynamic model. This paper describes a three step methodology for correct initialisation of power systems dynamic model for an ocean energy system. The methodology is validated using DIgSILENT Power Factory simulations.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123320554","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398572
F. Pellitteri, V. Boscaino, R. L. Rosa, G. Capponi
In this paper, a wireless charger for portable electronics devices is presented. A power transmitter, also known as the magnetic pad, and a power receiver are magnetically coupled. A receiver architecture which improves the power conversion efficiency is proposed. All advantages brought by the proposed architecture are discussed and standard constraints are presented as well. The receiver is fully standard-compliant. A wireless station for mobile application is designed and tested. Simulation and experimental results are compared. As shown by experimental results, thanks to the proposed architecture the power conversion efficiency of the receiver section is really close to a unit value. Power losses on the receiver side could be reasonably neglected. The wireless station efficiency now depends on the inductive coupling losses only.
{"title":"Improving the efficiency of a standard compliant wireless battery charger","authors":"F. Pellitteri, V. Boscaino, R. L. Rosa, G. Capponi","doi":"10.1109/UPEC.2012.6398572","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398572","url":null,"abstract":"In this paper, a wireless charger for portable electronics devices is presented. A power transmitter, also known as the magnetic pad, and a power receiver are magnetically coupled. A receiver architecture which improves the power conversion efficiency is proposed. All advantages brought by the proposed architecture are discussed and standard constraints are presented as well. The receiver is fully standard-compliant. A wireless station for mobile application is designed and tested. Simulation and experimental results are compared. As shown by experimental results, thanks to the proposed architecture the power conversion efficiency of the receiver section is really close to a unit value. Power losses on the receiver side could be reasonably neglected. The wireless station efficiency now depends on the inductive coupling losses only.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125073547","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398422
A. Cagnano, E. De Tuglie, M. Dicorato, G. Forte, M. Trovato
This paper deals with the development of a centralized nonlinear auto-adaptive controller able to optimize the network voltage profile by managing the reactive power supplied by PV inverters. The control design is based on a realtime optimization procedure involving the sensitivity theory in conjunction with the Lyapunov function and produces the control laws that must be sent to local controllers of PV-inverters. The derived controller is implemented and tested on a MV distribution network.
{"title":"PV plants for voltage regulation in distribution networks","authors":"A. Cagnano, E. De Tuglie, M. Dicorato, G. Forte, M. Trovato","doi":"10.1109/UPEC.2012.6398422","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398422","url":null,"abstract":"This paper deals with the development of a centralized nonlinear auto-adaptive controller able to optimize the network voltage profile by managing the reactive power supplied by PV inverters. The control design is based on a realtime optimization procedure involving the sensitivity theory in conjunction with the Lyapunov function and produces the control laws that must be sent to local controllers of PV-inverters. The derived controller is implemented and tested on a MV distribution network.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122010954","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398684
K. Oureilidis, C. Demoulias
The penetration of renewable energy sources in small-scale power production gives the opportunity parts of the grid to work as microgrids. The microgrid should be able to work both in grid-connected and island mode, while its voltage and frequency deviations follow the EN 50160 standard. The use of energy storage system is generally recommended in order to absorb the mismatches between the demand and the generation side and to preserve the quality of the microgrid voltage. While the up to day research is mainly concentrated on energy management based on communication, this paper proposes a wireless method for keeping the voltage and the frequency within the limits, using a battery as an energy storage system (ESS). An analytical expression for calculating the battery capacity is also proposed. The active and reactive power sharing among the parallel resources is achieved using the droop control method and an algorithm proportional to droop characteristic and the rated apparent power of each resource. According to the values of frequency and voltage and the State of Charge (SoC), the battery is connected in the microgrid, working in charging or discharging mode. A microgrid consisting of two inverter-interfaced power resources, a battery and a constant power load is investigated. Simulation results demonstrate that the proposed wireless control method provides the load with a high quality voltage in both grid-connected and islanded mode under several load scenarios.
{"title":"Microgrid wireless energy management with energy storage system","authors":"K. Oureilidis, C. Demoulias","doi":"10.1109/UPEC.2012.6398684","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398684","url":null,"abstract":"The penetration of renewable energy sources in small-scale power production gives the opportunity parts of the grid to work as microgrids. The microgrid should be able to work both in grid-connected and island mode, while its voltage and frequency deviations follow the EN 50160 standard. The use of energy storage system is generally recommended in order to absorb the mismatches between the demand and the generation side and to preserve the quality of the microgrid voltage. While the up to day research is mainly concentrated on energy management based on communication, this paper proposes a wireless method for keeping the voltage and the frequency within the limits, using a battery as an energy storage system (ESS). An analytical expression for calculating the battery capacity is also proposed. The active and reactive power sharing among the parallel resources is achieved using the droop control method and an algorithm proportional to droop characteristic and the rated apparent power of each resource. According to the values of frequency and voltage and the State of Charge (SoC), the battery is connected in the microgrid, working in charging or discharging mode. A microgrid consisting of two inverter-interfaced power resources, a battery and a constant power load is investigated. Simulation results demonstrate that the proposed wireless control method provides the load with a high quality voltage in both grid-connected and islanded mode under several load scenarios.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122648002","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398554
F. Gonzalez-Longatt, J. Roldan, C. Charalambous
This paper presents an algorithm for the sequential solution of the ac/dc power flow, which is proposed for the analysis of multi-terminal HVDC systems (MTDC). This sequential power flow algorithm can be implemented easily in an existing ac power flow package and is very flexible when it compared with unified methods. Gauss-Siedel algorithm is used to solve dc power balance equations, it offers two keys advantages: very fast and simple computational implementation, and errors do not accumulate during the calculation. The algorithm is tested using the WSCC 3-machine, 9-bus system with a 3-terminal MTDC network and results compared with those obtained from DIgSILENT® PowerFactoryTM demonstrating the validity of the proposed algorithm. As aggregate value, a representative test case of the projected scheme for the phase I of the Supergrid project on the North Sea is presented, the proposed approach presented in this paper is used to calculate DC power flows for some scenarios.
{"title":"Solution of ac/dc power flow on a multiterminal HVDC system: Illustrative case supergrid phase I","authors":"F. Gonzalez-Longatt, J. Roldan, C. Charalambous","doi":"10.1109/UPEC.2012.6398554","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398554","url":null,"abstract":"This paper presents an algorithm for the sequential solution of the ac/dc power flow, which is proposed for the analysis of multi-terminal HVDC systems (MTDC). This sequential power flow algorithm can be implemented easily in an existing ac power flow package and is very flexible when it compared with unified methods. Gauss-Siedel algorithm is used to solve dc power balance equations, it offers two keys advantages: very fast and simple computational implementation, and errors do not accumulate during the calculation. The algorithm is tested using the WSCC 3-machine, 9-bus system with a 3-terminal MTDC network and results compared with those obtained from DIgSILENT® PowerFactoryTM demonstrating the validity of the proposed algorithm. As aggregate value, a representative test case of the projected scheme for the phase I of the Supergrid project on the North Sea is presented, the proposed approach presented in this paper is used to calculate DC power flows for some scenarios.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129556047","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398611
P. L. Mantock, M. Moghadam, M. Darwish
This paper presents a new concept of an ultra-low loss cable which can be used in transmission and distribution systems. The cable has been developed by the reconfiguring of a capacitor which has a “theoretically” zero loss and practically ultra- low losses. The main idea behind this new concept is to present the cable as a linear capacitor where the power can be transmitted without any significant losses.
{"title":"A Charge Transfer Cable (CTC) ‘an ultra-low loss cable’","authors":"P. L. Mantock, M. Moghadam, M. Darwish","doi":"10.1109/UPEC.2012.6398611","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398611","url":null,"abstract":"This paper presents a new concept of an ultra-low loss cable which can be used in transmission and distribution systems. The cable has been developed by the reconfiguring of a capacitor which has a “theoretically” zero loss and practically ultra- low losses. The main idea behind this new concept is to present the cable as a linear capacitor where the power can be transmitted without any significant losses.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124881866","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398577
Sheng Wang, Jun Liang, J. Ekanayake
This paper presents an economical and technological comparison between a conventional point to point (PTP) VSC-HVDC system and a DC mesh grid. A case study based on Dogger Bank Creyke Beck is used for this investigation. In the economic comparison, three main components are considered- VSC converter, DC cable and DC circuit breaker. The cost of losses is analyzed and the investment cost is estimated. Simulation using PSCAD/EMTDC is undertaken to support the technology assessment. The system redundancy during normal conditions is presented while the performance of each topology during fault condition is also illustrated. It is concluded that a DC mesh grid is more flexible in technology aspect and saves the costs.
{"title":"Optimised topology design and comparison for offshore transmission","authors":"Sheng Wang, Jun Liang, J. Ekanayake","doi":"10.1109/UPEC.2012.6398577","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398577","url":null,"abstract":"This paper presents an economical and technological comparison between a conventional point to point (PTP) VSC-HVDC system and a DC mesh grid. A case study based on Dogger Bank Creyke Beck is used for this investigation. In the economic comparison, three main components are considered- VSC converter, DC cable and DC circuit breaker. The cost of losses is analyzed and the investment cost is estimated. Simulation using PSCAD/EMTDC is undertaken to support the technology assessment. The system redundancy during normal conditions is presented while the performance of each topology during fault condition is also illustrated. It is concluded that a DC mesh grid is more flexible in technology aspect and saves the costs.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122486726","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398598
Ahmad Abdel-Majeed, M. Braun
Accurate and reliable state estimation for low voltage networks is the core stone for flexible operation and control in the current transaction from passive conventional to active smart grids. The development in the energy supply has revealed a rapid increase of controllable distributed generators, consumer's installation, stationary storage systems and electric vehicles. This development leads to a significantly different kind of system behavior which must be understood first, and then to make suggestions for operational network improvements in order to increase the security and efficiency of the distribution system operation. For this, a high chronological and topological resolution of information for the system state estimation in the low voltage level is necessary. However, measurement data are necessary for state estimation, these measurements can be obtained either from the distribution system measurement infrastructure or from the smart meters at the connection points of the customer. The focus of this paper is to obtain the technical feasibility of using smart meter and their measurements for low voltage network observability and controllability through state estimation techniques. Also to analyse the impact of high accuracy measurement data provided from smart meters on the state estimation output accuracy for both voltage and it's phase angle.
{"title":"Low voltage system state estimation using smart meters","authors":"Ahmad Abdel-Majeed, M. Braun","doi":"10.1109/UPEC.2012.6398598","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398598","url":null,"abstract":"Accurate and reliable state estimation for low voltage networks is the core stone for flexible operation and control in the current transaction from passive conventional to active smart grids. The development in the energy supply has revealed a rapid increase of controllable distributed generators, consumer's installation, stationary storage systems and electric vehicles. This development leads to a significantly different kind of system behavior which must be understood first, and then to make suggestions for operational network improvements in order to increase the security and efficiency of the distribution system operation. For this, a high chronological and topological resolution of information for the system state estimation in the low voltage level is necessary. However, measurement data are necessary for state estimation, these measurements can be obtained either from the distribution system measurement infrastructure or from the smart meters at the connection points of the customer. The focus of this paper is to obtain the technical feasibility of using smart meter and their measurements for low voltage network observability and controllability through state estimation techniques. Also to analyse the impact of high accuracy measurement data provided from smart meters on the state estimation output accuracy for both voltage and it's phase angle.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125257041","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 : 2012-12-31DOI: 10.1109/UPEC.2012.6398431
R. Pereira, C. Ferreira, F. Barbosa
Voltage stability is predominantly a load stability phenomenon and solutions to voltage stability can be found by control of the load as seen from the bulk power network. A delay of the load restoration gives time for other corrective actions. The load restoration may be delayed and/or limited by certain countermeasures, such as blocking of Under Load Tap Changers (ULTC). In this paper it was studied the impact of the ULTC on the dynamic voltage collapse of an electric power system with large scale wind generation. It is used the Cigré Electric Power Network with 32 bus and three wind farms equipped with wind turbines, including pitch control coupled with a Fixed Speed Induction Generator (FSIG) and a shunt capacitor bank. The automatic voltage regulators (AVR) of the generating units and the turbine speed governors were modelled. Different load models were used and the ULTC were taken into account. Several significant disturbances were simulated in the test power network, such as the increase of the wind speed, the tripping of an overhead transmission line and three-phase short-circuits. The simulation results were obtained using the EUROSTAG software package. Finally, some conclusions that provide a better understanding of the ULTC effect on the dynamic voltage stability in a system with a large amount of wind power generation are pointed out.
{"title":"Impact of the ULTC on the dynamic voltage collapse of an electric power system with large scale of wind generation","authors":"R. Pereira, C. Ferreira, F. Barbosa","doi":"10.1109/UPEC.2012.6398431","DOIUrl":"https://doi.org/10.1109/UPEC.2012.6398431","url":null,"abstract":"Voltage stability is predominantly a load stability phenomenon and solutions to voltage stability can be found by control of the load as seen from the bulk power network. A delay of the load restoration gives time for other corrective actions. The load restoration may be delayed and/or limited by certain countermeasures, such as blocking of Under Load Tap Changers (ULTC). In this paper it was studied the impact of the ULTC on the dynamic voltage collapse of an electric power system with large scale wind generation. It is used the Cigré Electric Power Network with 32 bus and three wind farms equipped with wind turbines, including pitch control coupled with a Fixed Speed Induction Generator (FSIG) and a shunt capacitor bank. The automatic voltage regulators (AVR) of the generating units and the turbine speed governors were modelled. Different load models were used and the ULTC were taken into account. Several significant disturbances were simulated in the test power network, such as the increase of the wind speed, the tripping of an overhead transmission line and three-phase short-circuits. The simulation results were obtained using the EUROSTAG software package. Finally, some conclusions that provide a better understanding of the ULTC effect on the dynamic voltage stability in a system with a large amount of wind power generation are pointed out.","PeriodicalId":326950,"journal":{"name":"2012 47th International Universities Power Engineering Conference (UPEC)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127737152","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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