Pub Date : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162783
Timur Yunusov, W. Holderbaum, B. Potter
Distributed generation plays a key role in reducing CO2 emissions and losses in transmission of power. However, due to the nature of renewable resources, distributed generation requires suitable control strategies to assure reliability and optimality for the grid. Multi-agent systems are perfect candidates for providing distributed control of distributed generation stations as well as providing reliability and flexibility for the grid integration.
{"title":"Cost function for sub-agent elements in multi-agent energy management system","authors":"Timur Yunusov, W. Holderbaum, B. Potter","doi":"10.1109/ISGTEurope.2011.6162783","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162783","url":null,"abstract":"Distributed generation plays a key role in reducing CO2 emissions and losses in transmission of power. However, due to the nature of renewable resources, distributed generation requires suitable control strategies to assure reliability and optimality for the grid. Multi-agent systems are perfect candidates for providing distributed control of distributed generation stations as well as providing reliability and flexibility for the grid integration.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121250998","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162826
M. Waite, Li Zhang, B. Chong
Harmonic characteristics of a number of widely used appliances are investigated. Their cumulative effect on a 3-phase 4-wire distribution network, in terms of severity of harmonic disturbance and current unbalance, is explored. This data is used in designing an active power filter based on a 3-phase 4-leg flying capacitor multilevel converter to eliminate the harmonics and current unbalance. The controller is tuned according to an emulation of the measured current. The algorithm employs a modified dead-beat control law to overcome the response delays caused by harmonic extraction loop. Simulation results have shown significant improvement in current waveforms.
{"title":"Active power filtering for a three-phase four-wire network with unidentifiable harmonic loads","authors":"M. Waite, Li Zhang, B. Chong","doi":"10.1109/ISGTEurope.2011.6162826","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162826","url":null,"abstract":"Harmonic characteristics of a number of widely used appliances are investigated. Their cumulative effect on a 3-phase 4-wire distribution network, in terms of severity of harmonic disturbance and current unbalance, is explored. This data is used in designing an active power filter based on a 3-phase 4-leg flying capacitor multilevel converter to eliminate the harmonics and current unbalance. The controller is tuned according to an emulation of the measured current. The algorithm employs a modified dead-beat control law to overcome the response delays caused by harmonic extraction loop. Simulation results have shown significant improvement in current waveforms.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134593648","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162782
L. Kumpulainen, S. Pettissalo, P. Trygg, K. Malmberg, M. Loukkalahti, Markku Hyvärinen
This paper reports the key features and practical experience gained so far of a unique distribution network monitoring and control system. Intelligent components and communication equipment at MV/LV substations have enabled extension of SCADA and DMS systems from HV/MV substations down to LV level. The functionality includes e.g. power quality monitoring, control of MV switches, and MV fault indication. Putting various functions together, the system is a real example of changing the grid smarter and providing tools for network asset management. Practical examples and experience of the system are reported in the paper.
{"title":"Improved monitoring and control of distribution network by smart MV/LV substations","authors":"L. Kumpulainen, S. Pettissalo, P. Trygg, K. Malmberg, M. Loukkalahti, Markku Hyvärinen","doi":"10.1109/ISGTEurope.2011.6162782","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162782","url":null,"abstract":"This paper reports the key features and practical experience gained so far of a unique distribution network monitoring and control system. Intelligent components and communication equipment at MV/LV substations have enabled extension of SCADA and DMS systems from HV/MV substations down to LV level. The functionality includes e.g. power quality monitoring, control of MV switches, and MV fault indication. Putting various functions together, the system is a real example of changing the grid smarter and providing tools for network asset management. Practical examples and experience of the system are reported in the paper.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124227584","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162780
S. Paoletti, M. Casini, Antonio Giannitrapani, A. Facchini, A. Garulli, A. Vicino
This paper addresses the problem of electric load forecasting for distribution networks with Active Demand (AD), a new concept in smart-grids introduced within the EU project ADDRESS. By changing the typical consumption pattern of the consumers, AD adds a new dimension to the problem of load forecasting, and therefore makes currently available load forecasting techniques no more suitable. A new approach to load forecasting in the presence of AD is therefore proposed. The approach is based on a decomposition of the load into its components, namely the base load (representing different seasonal patterns), and a residual term depending both on stochastic fluctuations and AD effects. The performance of the proposed approach is illustrated through a numerical example. Since data sets including AD are not yet available, in the numerical example AD effects are simulated and added to real measurements representing the aggregated load of about 60 consumers from an Italian LV network.
{"title":"Load forecasting for active distribution networks","authors":"S. Paoletti, M. Casini, Antonio Giannitrapani, A. Facchini, A. Garulli, A. Vicino","doi":"10.1109/ISGTEurope.2011.6162780","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162780","url":null,"abstract":"This paper addresses the problem of electric load forecasting for distribution networks with Active Demand (AD), a new concept in smart-grids introduced within the EU project ADDRESS. By changing the typical consumption pattern of the consumers, AD adds a new dimension to the problem of load forecasting, and therefore makes currently available load forecasting techniques no more suitable. A new approach to load forecasting in the presence of AD is therefore proposed. The approach is based on a decomposition of the load into its components, namely the base load (representing different seasonal patterns), and a residual term depending both on stochastic fluctuations and AD effects. The performance of the proposed approach is illustrated through a numerical example. Since data sets including AD are not yet available, in the numerical example AD effects are simulated and added to real measurements representing the aggregated load of about 60 consumers from an Italian LV network.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132875225","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162650
Irinel-Sorin Ilie, I. Hernando‐Gil, A. Collin, J. Acosta, S. Djokic
The paper discusses possible impact of demand-side management (DSM) functionalities on the improvement of reliability performance and formulation of novel reliability assessment procedures of future electricity networks (so called “smart grids”). Firstly, traditionally used continuity of supply metrics and indices are assessed for a given reliability test system without considering any DSM scheme. Differences in the results for reliability indices for test system modelled with bulk loads and system modelled with detailed network configurations supplying connected loads are quantified, emphasising the errors that occur when parts of the system are neglected during the estimations of reliability performance. Afterwards, the effect of DSM on the reliability performance of the same test network are analysed, in order to assess potential benefits of DSM to the network operators, particularly with respect to their annual performance reports. Finally, possible changes in used reliability metrics are discussed, as smart grids will allow to substitute standard lumped representation of system loads at higher voltage levels with a more accurate and detailed information on load demands and load structures, including estimated contribution of demand-manageable portion of system load to the total demand.
{"title":"Reliability performance assessment in smart grids with demand-side management","authors":"Irinel-Sorin Ilie, I. Hernando‐Gil, A. Collin, J. Acosta, S. Djokic","doi":"10.1109/ISGTEurope.2011.6162650","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162650","url":null,"abstract":"The paper discusses possible impact of demand-side management (DSM) functionalities on the improvement of reliability performance and formulation of novel reliability assessment procedures of future electricity networks (so called “smart grids”). Firstly, traditionally used continuity of supply metrics and indices are assessed for a given reliability test system without considering any DSM scheme. Differences in the results for reliability indices for test system modelled with bulk loads and system modelled with detailed network configurations supplying connected loads are quantified, emphasising the errors that occur when parts of the system are neglected during the estimations of reliability performance. Afterwards, the effect of DSM on the reliability performance of the same test network are analysed, in order to assess potential benefits of DSM to the network operators, particularly with respect to their annual performance reports. Finally, possible changes in used reliability metrics are discussed, as smart grids will allow to substitute standard lumped representation of system loads at higher voltage levels with a more accurate and detailed information on load demands and load structures, including estimated contribution of demand-manageable portion of system load to the total demand.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117225652","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162796
A. Venturi, P. Clarkson, A. Forbes, E. Davidson, A. Roscoe, G. Burt, Xin-She Yang, P. Wright
The necessity of developing alternatives to fossil combustibles as energy sources is increasingly leading towards non-conventional, renewable and distributed generation systems. To manage the transition from the present centralized grid to the future active systems consisting of multiple bi-directional energy clients it is necessary to extend the measurement systems to LV grids. The overall objective of this work is to install real-time measuring devices at a few grid locations, and use distribution state estimation techniques to implement active network management techniques on an experimental 100-kVA micro-grid.
{"title":"The role of accurate measurements within smartgrids","authors":"A. Venturi, P. Clarkson, A. Forbes, E. Davidson, A. Roscoe, G. Burt, Xin-She Yang, P. Wright","doi":"10.1109/ISGTEurope.2011.6162796","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162796","url":null,"abstract":"The necessity of developing alternatives to fossil combustibles as energy sources is increasingly leading towards non-conventional, renewable and distributed generation systems. To manage the transition from the present centralized grid to the future active systems consisting of multiple bi-directional energy clients it is necessary to extend the measurement systems to LV grids. The overall objective of this work is to install real-time measuring devices at a few grid locations, and use distribution state estimation techniques to implement active network management techniques on an experimental 100-kVA micro-grid.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114726975","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162707
I. Vechiu, Aitor Etxeberria, H. Camblong, J. Vinassa
Microgrids can potentially improve security, quality, reliability and availability of electricity supply for many applications. In order to achieve these benefits when a microgrid with a substantial amount of stochastic generation operates in grid connected mode but also during islanding mode, the use of storage systems is essential. The main goal of the storage is to perform power balance during islanding mode and to avoid the effect of the renewable energy sources intermittency and load fluctuations to the grid. However, none of the currently available Energy Storage Systems (ESS) has the necessary high power and energy densities to face the effect of different disturbances coming from the load or renewable energy sources. Thus, the association of more than one storage technology in a Hybrid Energy Storage System (HESS) can be used to satisfy the above mentioned requirements. Generally, separate DC/DC converters are required to interconnect the different ESS with an inverter in order to supply the distributed system in a microgrid. The present work proposes the association of a Vanadium-Redox flow battery (VRB) with supercapacitors and a Three-level Neutral Point Clamped Inverter Interface for energy management in a microgrid. The power converter control and the energy management are also detailed. Simulation results are presented to prove the feasibility of the proposed system.
{"title":"Three-level Neutral Point Clamped Inverter Interface for flow battery/supercapacitor Energy Storage System used for microgrids","authors":"I. Vechiu, Aitor Etxeberria, H. Camblong, J. Vinassa","doi":"10.1109/ISGTEurope.2011.6162707","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162707","url":null,"abstract":"Microgrids can potentially improve security, quality, reliability and availability of electricity supply for many applications. In order to achieve these benefits when a microgrid with a substantial amount of stochastic generation operates in grid connected mode but also during islanding mode, the use of storage systems is essential. The main goal of the storage is to perform power balance during islanding mode and to avoid the effect of the renewable energy sources intermittency and load fluctuations to the grid. However, none of the currently available Energy Storage Systems (ESS) has the necessary high power and energy densities to face the effect of different disturbances coming from the load or renewable energy sources. Thus, the association of more than one storage technology in a Hybrid Energy Storage System (HESS) can be used to satisfy the above mentioned requirements. Generally, separate DC/DC converters are required to interconnect the different ESS with an inverter in order to supply the distributed system in a microgrid. The present work proposes the association of a Vanadium-Redox flow battery (VRB) with supercapacitors and a Three-level Neutral Point Clamped Inverter Interface for energy management in a microgrid. The power converter control and the energy management are also detailed. Simulation results are presented to prove the feasibility of the proposed system.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115222727","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162732
D. Papadaskalopoulos, G. Strbac
In the emerging power systems setting, the realization of the demand flexibility potential needs to be coupled with its integration in electricity markets. Decentralization of market mechanisms constitutes a major challenge towards the achievement of such integration. In this paper, a decentralized day-ahead pool market mechanism is proposed, based on Lagrangian Relaxation (LR) principles. Issues related to demand participation through the proposed mechanism are addressed from the perspective of electric vehicles (EV) due to their significant flexibility potential. Their local, surplus maximization bidding problems are formulated taking into account their detailed, inter-temporal characteristics. Discontinuities in their market behaviour and their impacts on equilibrium existence are identified and a suitable LR-heuristic method is proposed to reach a satisfactory feasible market clearing solution when such discontinuities make an equilibrium solution unattainable. Benefits realized through the proposed approaches are quantified and analyzed through suitable case studies.
{"title":"Participation of electric vehicles in electricity markets through a decentralized mechanism","authors":"D. Papadaskalopoulos, G. Strbac","doi":"10.1109/ISGTEurope.2011.6162732","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162732","url":null,"abstract":"In the emerging power systems setting, the realization of the demand flexibility potential needs to be coupled with its integration in electricity markets. Decentralization of market mechanisms constitutes a major challenge towards the achievement of such integration. In this paper, a decentralized day-ahead pool market mechanism is proposed, based on Lagrangian Relaxation (LR) principles. Issues related to demand participation through the proposed mechanism are addressed from the perspective of electric vehicles (EV) due to their significant flexibility potential. Their local, surplus maximization bidding problems are formulated taking into account their detailed, inter-temporal characteristics. Discontinuities in their market behaviour and their impacts on equilibrium existence are identified and a suitable LR-heuristic method is proposed to reach a satisfactory feasible market clearing solution when such discontinuities make an equilibrium solution unattainable. Benefits realized through the proposed approaches are quantified and analyzed through suitable case studies.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115068691","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162748
J. Rodrigues, F. O. Resende, C. Moreira
This paper proposes technical solutions that can be implemented in variable speed permanent magnet synchronous generators driven wind turbine systems aiming to mitigate high voltage problems in low voltage MicroGrids by controlling the active power output. Due to the limited control capability of these systems, controlling the output power to prevent voltage rise will require the local accommodation of the generation surplus. For this purpose, additional control functionalities are developed to be integrated in the control systems of the power electronic based interfaces. Their performance is evaluated through numerical simulations performed in Matlab®/Simulink® environment and considering the detailed models of the power electronic converters. The results obtained demonstrate the effectiveness of the proposed control functionalities.
{"title":"Contribution of PMSG based small wind generation systems to provide voltage control in low voltage networks","authors":"J. Rodrigues, F. O. Resende, C. Moreira","doi":"10.1109/ISGTEurope.2011.6162748","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162748","url":null,"abstract":"This paper proposes technical solutions that can be implemented in variable speed permanent magnet synchronous generators driven wind turbine systems aiming to mitigate high voltage problems in low voltage MicroGrids by controlling the active power output. Due to the limited control capability of these systems, controlling the output power to prevent voltage rise will require the local accommodation of the generation surplus. For this purpose, additional control functionalities are developed to be integrated in the control systems of the power electronic based interfaces. Their performance is evaluated through numerical simulations performed in Matlab®/Simulink® environment and considering the detailed models of the power electronic converters. The results obtained demonstrate the effectiveness of the proposed control functionalities.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"276 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115068708","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 : 2011-12-01DOI: 10.1109/ISGTEurope.2011.6162831
P. Kadurek, J. Cobben, W. Kling
The current distribution networks are going to be challenged by new developments on the side of generation and simultaneously also on the side of consumption. Therefore this paper provides an overview of LV network design aspects with emphasis on the implications of the future challenges on LV networks. The attention is especially given to the future aspect of the network design, substation automation, protection and mitigation of the issues accompanying distributed generation. The current operational and power quality measurements undertaken in LV distribution networks are presented as well as new additional measurements. The need to increase flexibility and assets utilization of LV networks is discussed together with the technical means enabling them. The outcomes related to the future LV network design are presented in conclusions.
{"title":"Future LV distribution network design and current practices in the Netherlands","authors":"P. Kadurek, J. Cobben, W. Kling","doi":"10.1109/ISGTEurope.2011.6162831","DOIUrl":"https://doi.org/10.1109/ISGTEurope.2011.6162831","url":null,"abstract":"The current distribution networks are going to be challenged by new developments on the side of generation and simultaneously also on the side of consumption. Therefore this paper provides an overview of LV network design aspects with emphasis on the implications of the future challenges on LV networks. The attention is especially given to the future aspect of the network design, substation automation, protection and mitigation of the issues accompanying distributed generation. The current operational and power quality measurements undertaken in LV distribution networks are presented as well as new additional measurements. The need to increase flexibility and assets utilization of LV networks is discussed together with the technical means enabling them. The outcomes related to the future LV network design are presented in conclusions.","PeriodicalId":419250,"journal":{"name":"2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies","volume":"46 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121295724","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：