Pub Date : 2013-06-13DOI: 10.1109/ICPEC.2013.6527688
M. Soheilirad, H. Hizam, P. Farzan, M. Hojabri, S. N. Fallah, G. Soheilirad
In this paper a new evolutionary computing method based on imperialist competitive algorithm (ICA) is used for optimization of the reactive power in a wind farm. The output power and also the reactive power of wind farms are not constant due to the oscillation in wind speed. Reactive power optimization is known as an efficient way to have an improvement in power quality and also to reduce power loss. The conventional optimization algorithms have some drawbacks, such as slow convergence and premature. ICA as one of the newest optimization algorithm could be applied in order to optimization of the reactive power and overcomes the difficulties which are coming from the traditional methods. In this paper, the reactive power consumption of a wind turbine is optimized by using (ICA) method. To illustrate the application of the method, a wind farm with some uncertainties is provided. Finally the results of the ICA method are compared with the one of conventional method. Results show that the proposed reactive power optimization method is simple and effective.
{"title":"Wind farm reactive power optimization by using imperialist competitive algorithm","authors":"M. Soheilirad, H. Hizam, P. Farzan, M. Hojabri, S. N. Fallah, G. Soheilirad","doi":"10.1109/ICPEC.2013.6527688","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527688","url":null,"abstract":"In this paper a new evolutionary computing method based on imperialist competitive algorithm (ICA) is used for optimization of the reactive power in a wind farm. The output power and also the reactive power of wind farms are not constant due to the oscillation in wind speed. Reactive power optimization is known as an efficient way to have an improvement in power quality and also to reduce power loss. The conventional optimization algorithms have some drawbacks, such as slow convergence and premature. ICA as one of the newest optimization algorithm could be applied in order to optimization of the reactive power and overcomes the difficulties which are coming from the traditional methods. In this paper, the reactive power consumption of a wind turbine is optimized by using (ICA) method. To illustrate the application of the method, a wind farm with some uncertainties is provided. Finally the results of the ICA method are compared with the one of conventional method. Results show that the proposed reactive power optimization method is simple and effective.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"33 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128733406","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527755
P. Gopakumar, M. J. B. Reddy, D. K. Mohanta
The rising concerns over the environmental impacts of conventional power plants pave the way for better utilization of renewable energy sources. The smarter networks like microgrids fed with renewable sources are being employed across the globe. Compared to conventional power plants, Microgrid operations are eco-friendly and better quality power is delivered to the consumers. But the increased penetration of these microgrids weakens the overall power system inertia which declines the power system stability. This paper presents a low power microgrid system to solve this problem. In contrast with usual microgrids, the proposed microgrid operates in islanded mode during normal operating conditions. It is operated in grid connected mode only when the output from renewable sources is insufficient for meeting the load demand. Better utilization of renewable energies with minimal stability impacts can be achieved with the proposed scheme.
{"title":"Renewable energy utilization using low power microgrid system","authors":"P. Gopakumar, M. J. B. Reddy, D. K. Mohanta","doi":"10.1109/ICPEC.2013.6527755","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527755","url":null,"abstract":"The rising concerns over the environmental impacts of conventional power plants pave the way for better utilization of renewable energy sources. The smarter networks like microgrids fed with renewable sources are being employed across the globe. Compared to conventional power plants, Microgrid operations are eco-friendly and better quality power is delivered to the consumers. But the increased penetration of these microgrids weakens the overall power system inertia which declines the power system stability. This paper presents a low power microgrid system to solve this problem. In contrast with usual microgrids, the proposed microgrid operates in islanded mode during normal operating conditions. It is operated in grid connected mode only when the output from renewable sources is insufficient for meeting the load demand. Better utilization of renewable energies with minimal stability impacts can be achieved with the proposed scheme.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115262211","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527701
P. Sundarajan, K. Ramakrishnan
In this paper, the problem of delay-dependent robust stability of a class of discrete-time systems with time-varying state-delays and norm bounded parametric uncertainties has been considered using Lyapunov Krasovskii functional (LK) approach. By employing a new candidate for the LK functional, and by using the recently reported finite sum inequality for the bounding the forward difference of the LK functional, a robust stability criterion that is less conservative and computationally less effective is derived in LMI framework. To illustrate the effectiveness of the proposed result against the existing result, a numerical example is employed.
{"title":"Robust stability analysis of uncertain discrete-time systems with time-varying feedback loop delays","authors":"P. Sundarajan, K. Ramakrishnan","doi":"10.1109/ICPEC.2013.6527701","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527701","url":null,"abstract":"In this paper, the problem of delay-dependent robust stability of a class of discrete-time systems with time-varying state-delays and norm bounded parametric uncertainties has been considered using Lyapunov Krasovskii functional (LK) approach. By employing a new candidate for the LK functional, and by using the recently reported finite sum inequality for the bounding the forward difference of the LK functional, a robust stability criterion that is less conservative and computationally less effective is derived in LMI framework. To illustrate the effectiveness of the proposed result against the existing result, a numerical example is employed.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127402557","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527652
S. Varshney, L. Srivastava, M. Pandit, M. Sharma
In recent years, voltage instability has been responsible for several incidents of major voltage collapses. For stable operation of power system, fast and accurate contingency analysis is required. Voltage stability contingency analysis requires computation of voltage stability margin accurately for each contingency case. This approach is time consuming, particularly in practical power systems where the number of contingencies is very large. This paper proposes a fast and accurate method for contingency ranking using distributed computing. In distributed computing, different parts of a program or the same program may be executed simultaneously on group of computers, which are communicating with each other over a network. The general-purpose computers that are networked can be utilized for distributed computing purpose. The effectiveness of the proposed approach has been tested on IEEE 30-bus system. The proposed distributed computing based approach for contingency ranking is found to be computationally efficient and provides near linear speedups.
{"title":"Voltage stability based contingency ranking using distributed computing environment","authors":"S. Varshney, L. Srivastava, M. Pandit, M. Sharma","doi":"10.1109/ICPEC.2013.6527652","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527652","url":null,"abstract":"In recent years, voltage instability has been responsible for several incidents of major voltage collapses. For stable operation of power system, fast and accurate contingency analysis is required. Voltage stability contingency analysis requires computation of voltage stability margin accurately for each contingency case. This approach is time consuming, particularly in practical power systems where the number of contingencies is very large. This paper proposes a fast and accurate method for contingency ranking using distributed computing. In distributed computing, different parts of a program or the same program may be executed simultaneously on group of computers, which are communicating with each other over a network. The general-purpose computers that are networked can be utilized for distributed computing purpose. The effectiveness of the proposed approach has been tested on IEEE 30-bus system. The proposed distributed computing based approach for contingency ranking is found to be computationally efficient and provides near linear speedups.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"29 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127613337","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527744
V. Reddy, S. N. Rao, C. Babu
Pulse width modulated (PWM) techniques of a voltage source inverter need a reference signal and carrier signal to generate the required modulating signals for the desired output. Modifications in Modulating techniques can be considered in two ways, namely Modified reference and Modified carrier. The existing multilevel carrier-based pulse width modulation strategies have no special provisions to offer quality output, besides lower order harmonics are introduced in the spectrum, especially at low switching frequencies. This paper proposes a novel multilevel PWM strategy to corner the advantages of low frequency switching and reduced total harmonic distortion (THD). This paper also presents the most relevant control and modulation methods by a new reference/carrier based PWM scheme for Cascaded Multilevel Inverter and comparing the performance of the proposed scheme with that of the existing control schemes. A prototype is developed for a single-phase 5-level cascaded inverter fed drive using VHDL programming with FPGA.
{"title":"Emphasis of modulated techniques for cascaded multilevel inverters fed drive using FPGA","authors":"V. Reddy, S. N. Rao, C. Babu","doi":"10.1109/ICPEC.2013.6527744","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527744","url":null,"abstract":"Pulse width modulated (PWM) techniques of a voltage source inverter need a reference signal and carrier signal to generate the required modulating signals for the desired output. Modifications in Modulating techniques can be considered in two ways, namely Modified reference and Modified carrier. The existing multilevel carrier-based pulse width modulation strategies have no special provisions to offer quality output, besides lower order harmonics are introduced in the spectrum, especially at low switching frequencies. This paper proposes a novel multilevel PWM strategy to corner the advantages of low frequency switching and reduced total harmonic distortion (THD). This paper also presents the most relevant control and modulation methods by a new reference/carrier based PWM scheme for Cascaded Multilevel Inverter and comparing the performance of the proposed scheme with that of the existing control schemes. A prototype is developed for a single-phase 5-level cascaded inverter fed drive using VHDL programming with FPGA.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126359152","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527651
S. Hameed, P. Garg, S. K. Varshney
Multi-machine power system stability improvement by tuning of Static Var Compensator (SVC)-based controller parameters is investigated in the proposed method. The design problem is formulated as an optimization problem with a timedomain simulation-based objective function and Real-Coded Genetic Algorithm (RCGA) is used for searching optimal controller parameters. A multi-machine power system model is developed using MATLAB's SIMULINK which incorporates SVC Controller. A fault is created on the transmission line. The simulation results of the multi-machine power system without SVC Controller and with SVC Controller are presented. The simulation results are analyzed which shows that the power system becomes unstable on the occurrence of the fault if SVC controller is not used. This paper shows the effectiveness of the proposed design. The proposed method enhances the multi-machine power system stability.
{"title":"Power system stability enhancement with genetically optimized SVC controller","authors":"S. Hameed, P. Garg, S. K. Varshney","doi":"10.1109/ICPEC.2013.6527651","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527651","url":null,"abstract":"Multi-machine power system stability improvement by tuning of Static Var Compensator (SVC)-based controller parameters is investigated in the proposed method. The design problem is formulated as an optimization problem with a timedomain simulation-based objective function and Real-Coded Genetic Algorithm (RCGA) is used for searching optimal controller parameters. A multi-machine power system model is developed using MATLAB's SIMULINK which incorporates SVC Controller. A fault is created on the transmission line. The simulation results of the multi-machine power system without SVC Controller and with SVC Controller are presented. The simulation results are analyzed which shows that the power system becomes unstable on the occurrence of the fault if SVC controller is not used. This paper shows the effectiveness of the proposed design. The proposed method enhances the multi-machine power system stability.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131394212","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527751
S. S. Hosseini, A. Badri, M. Parvania
The growth of customer preferences towards plug-in hybrid electrical vehicles (PHEVs) is becoming more than before. The batteries of these vehicles need to be charged through plugging-in electric grids at home or parking station. By increasing number of PHEVs, these electric loads might have the impacts on the power system efficiency. The impacts specifically could endanger the distribution and micro grids performance, via difficulties such as overloading, power quality or voltage regulation. To overcome this problem charging scenarios are represented that optimize EVs charging at home from a standard outlet. But regarding the importance of smart parking lots, this work explores solving these challenges by replacing PHEVs in a parking station. The paper analyzes charging scenarios in the context of a parking lot. A residential grid is considered to verify this concept. In a new approach smart parking lot is developed and located based on customer priorities. The paper also investigates the integration of renewable energy into the parking lot to supply PHEVs.
{"title":"Smart parking lot to minimize residential grid losses based on customer priorities","authors":"S. S. Hosseini, A. Badri, M. Parvania","doi":"10.1109/ICPEC.2013.6527751","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527751","url":null,"abstract":"The growth of customer preferences towards plug-in hybrid electrical vehicles (PHEVs) is becoming more than before. The batteries of these vehicles need to be charged through plugging-in electric grids at home or parking station. By increasing number of PHEVs, these electric loads might have the impacts on the power system efficiency. The impacts specifically could endanger the distribution and micro grids performance, via difficulties such as overloading, power quality or voltage regulation. To overcome this problem charging scenarios are represented that optimize EVs charging at home from a standard outlet. But regarding the importance of smart parking lots, this work explores solving these challenges by replacing PHEVs in a parking station. The paper analyzes charging scenarios in the context of a parking lot. A residential grid is considered to verify this concept. In a new approach smart parking lot is developed and located based on customer priorities. The paper also investigates the integration of renewable energy into the parking lot to supply PHEVs.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131754943","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527729
S. S. Matharu, S. Bhalla, R. Jarial
As a result of increasing demand of electricity, one way of generating renewable energy sources is from wind turbines. The places across the world where velocity of wind is conducive for power generation, the wind turbines influence the behavior of power system. In this paper, a wind turbine connected with DFIG for Wind Energy Conversion using sherbius drive with vector control is modeled, in the power system simulation tool, PSCAD/EMTDC and outputs are simulated to investigate the presence of flicker at the point of common coupling. The impact of wind speed variation on the voltage & current waveforms is investigated so as to assess the Power Quality. The vector control method is implemented to ensure decoupled control of active and reactive powers while ensuring the maximum energy capture from the wind. It is concluded that wind speed variation results in predominant flicker during transient period, however the DFIG model is capable of suppressing the same. Efforts can still be made to mitigate the flicker by flicker control scheme so as to improve the Power Quality of associated Networks in National Endeavour.
{"title":"Flicker assessment of grid connected DFIG for wind energy conversion systems","authors":"S. S. Matharu, S. Bhalla, R. Jarial","doi":"10.1109/ICPEC.2013.6527729","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527729","url":null,"abstract":"As a result of increasing demand of electricity, one way of generating renewable energy sources is from wind turbines. The places across the world where velocity of wind is conducive for power generation, the wind turbines influence the behavior of power system. In this paper, a wind turbine connected with DFIG for Wind Energy Conversion using sherbius drive with vector control is modeled, in the power system simulation tool, PSCAD/EMTDC and outputs are simulated to investigate the presence of flicker at the point of common coupling. The impact of wind speed variation on the voltage & current waveforms is investigated so as to assess the Power Quality. The vector control method is implemented to ensure decoupled control of active and reactive powers while ensuring the maximum energy capture from the wind. It is concluded that wind speed variation results in predominant flicker during transient period, however the DFIG model is capable of suppressing the same. Efforts can still be made to mitigate the flicker by flicker control scheme so as to improve the Power Quality of associated Networks in National Endeavour.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129527222","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527649
V. B. Murthy, S. Nagar
This paper presents a reliable analytical mathematical model for estimation of the steady state performance of large capacity turbo generators. The model emphasizes on inclusion of the magnetic saturation factors in the performance prediction of the generators. The analytical calculations are validated with the tests performed. The influence of the basic design parameters on the performance estimation are discussed in detail. The application of the developed model on a new design is outlined.
{"title":"Analytical estimation of steady state performance of large capacity turbo-generators","authors":"V. B. Murthy, S. Nagar","doi":"10.1109/ICPEC.2013.6527649","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527649","url":null,"abstract":"This paper presents a reliable analytical mathematical model for estimation of the steady state performance of large capacity turbo generators. The model emphasizes on inclusion of the magnetic saturation factors in the performance prediction of the generators. The analytical calculations are validated with the tests performed. The influence of the basic design parameters on the performance estimation are discussed in detail. The application of the developed model on a new design is outlined.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132446076","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 : 2013-06-13DOI: 10.1109/ICPEC.2013.6527659
M. SuganyaBharathi, M. Iruthayarajan, S. Shunmugam, L. Kalaivani
Dissolved Gas Analysis (DGA) is used to determine the faults occurred in transformer oil by analyzing the gas evolved from it. This paper has presented the application of Fuzzy Logic system for dissolved gas analysis. DGA results were carried out and the possibility of improving the diagnosis with the aid of Fuzzy Logic system has been brought out. The results show that higher value of accuracy for predicted cases when compared to others. By combining various DGA techniques and interpreting classical DGA with Fuzzy Logic system approach, we have increased the predictability of the tool with the reduced time and maneuver.
{"title":"Interpretation of dissolved gas analysis in transformer oil using fuzzy logic system","authors":"M. SuganyaBharathi, M. Iruthayarajan, S. Shunmugam, L. Kalaivani","doi":"10.1109/ICPEC.2013.6527659","DOIUrl":"https://doi.org/10.1109/ICPEC.2013.6527659","url":null,"abstract":"Dissolved Gas Analysis (DGA) is used to determine the faults occurred in transformer oil by analyzing the gas evolved from it. This paper has presented the application of Fuzzy Logic system for dissolved gas analysis. DGA results were carried out and the possibility of improving the diagnosis with the aid of Fuzzy Logic system has been brought out. The results show that higher value of accuracy for predicted cases when compared to others. By combining various DGA techniques and interpreting classical DGA with Fuzzy Logic system approach, we have increased the predictability of the tool with the reduced time and maneuver.","PeriodicalId":176900,"journal":{"name":"2013 International Conference on Power, Energy and Control (ICPEC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127629016","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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