The presence of nonlinear and unbalanced loads in the single phase networks increases the harmonics and losses in power grid. The active power filters solve these problems, and in addition to reducing any arbitrary harmonic component, it will eliminate the possibility of resonance with the network. In this paper, an active power filter (APF) based on voltage source converter (VSC) is used to reduce the THD contents of single phase grid current which are applied to a non-linear load. A new hybrid hysteresis current control scheme with a DC link capacitor voltage regulator based on conventional PI controller is proposed to generate the gating signals of APF. The performance of the proposed controller in terms of reducing the THD contents of grid current and power quality improvement is evaluated using MATLAB/Simulink and also an experimental setup is implemented to confirm the simulation results.
{"title":"Control Strategy of a Single Phase Active Power Filter with Adjustable DC Link Capacitor Voltage for THD Reduction in Non-linear Loads","authors":"Amin Talebkhah, Milad Samady Shadlu, Seyyed Majid Fatemi","doi":"10.1109/PEDSTC.2019.8697234","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697234","url":null,"abstract":"The presence of nonlinear and unbalanced loads in the single phase networks increases the harmonics and losses in power grid. The active power filters solve these problems, and in addition to reducing any arbitrary harmonic component, it will eliminate the possibility of resonance with the network. In this paper, an active power filter (APF) based on voltage source converter (VSC) is used to reduce the THD contents of single phase grid current which are applied to a non-linear load. A new hybrid hysteresis current control scheme with a DC link capacitor voltage regulator based on conventional PI controller is proposed to generate the gating signals of APF. The performance of the proposed controller in terms of reducing the THD contents of grid current and power quality improvement is evaluated using MATLAB/Simulink and also an experimental setup is implemented to confirm the simulation results.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121167194","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697239
Naser Hassan Pour, K. Varesi
This paper proposes a new high gain dc-dc converter. The proposed topology has simple control and structure. The input and output (load) current waveforms are continuous. The continuous character of input current of suggested converter candidates it as a suitable choice for application in renewable energy industry, where the Maximum Power Point Tracking (MPPT) can easily be achieved. Usually the transformerless converters suffer from low gain, but the suggested converter has extra high gain, in spite of its non-isolated and non-coupled inductor nature. The gain per number of elements in proposed topology is more than other similar topologies. Despite the high gain, the Normalized Voltage Stress (NVS) on switches/diodes of proposed topology is considerably low. In this paper, the proposed topology has been introduced and its operational modes have been explained. The steady state analysis have also been presented. To assess the proposed topology, it has been contrasted with similar novel topologies. Comparison results validate the advantages of proposed topology. The obtained simulation results (done in PSCAD/EMTDC) confirm the effective operation of proposed topology.
{"title":"A New Non-Isolated High Gain DC-DC Converter Suitable for Renewable Energies","authors":"Naser Hassan Pour, K. Varesi","doi":"10.1109/PEDSTC.2019.8697239","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697239","url":null,"abstract":"This paper proposes a new high gain dc-dc converter. The proposed topology has simple control and structure. The input and output (load) current waveforms are continuous. The continuous character of input current of suggested converter candidates it as a suitable choice for application in renewable energy industry, where the Maximum Power Point Tracking (MPPT) can easily be achieved. Usually the transformerless converters suffer from low gain, but the suggested converter has extra high gain, in spite of its non-isolated and non-coupled inductor nature. The gain per number of elements in proposed topology is more than other similar topologies. Despite the high gain, the Normalized Voltage Stress (NVS) on switches/diodes of proposed topology is considerably low. In this paper, the proposed topology has been introduced and its operational modes have been explained. The steady state analysis have also been presented. To assess the proposed topology, it has been contrasted with similar novel topologies. Comparison results validate the advantages of proposed topology. The obtained simulation results (done in PSCAD/EMTDC) confirm the effective operation of proposed topology.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121507936","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697276
H. Beiranvand, E. Rokrok, Marco Liserre
Heatsink is a passive component for transferring heat due to power losses from power devices such as semiconductor switches in power electronic converters. Emerging semiconductor technologies such as GaN and SiC MOSFETs present lower conduction and switching losses than conventional Si devices which can led to increase efficiency and reduction of weight and volume. In this paper, comparative evaluation of the heatsink weight and volume optimization based on Si IGBT, SiC MOSFET and GaN is done in a dual-active-bridge (DAB) as a building block in solid-state transformers. A 5 kW DAB converter as one of the 16 modules in an 80 kW ISOP converter is considered in optimization. Heatsink design is done for three semiconductor types. Results show that GaN achieves lowest power losses while its heatsink size and volume is limited by the thermal properties of the GaN chip.
{"title":"Comparative Study of Heatsink Volume and Weight Optimization in SST DAB cells Employing GaN, SiC-MOSFET and Si-IGBT Switches","authors":"H. Beiranvand, E. Rokrok, Marco Liserre","doi":"10.1109/PEDSTC.2019.8697276","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697276","url":null,"abstract":"Heatsink is a passive component for transferring heat due to power losses from power devices such as semiconductor switches in power electronic converters. Emerging semiconductor technologies such as GaN and SiC MOSFETs present lower conduction and switching losses than conventional Si devices which can led to increase efficiency and reduction of weight and volume. In this paper, comparative evaluation of the heatsink weight and volume optimization based on Si IGBT, SiC MOSFET and GaN is done in a dual-active-bridge (DAB) as a building block in solid-state transformers. A 5 kW DAB converter as one of the 16 modules in an 80 kW ISOP converter is considered in optimization. Heatsink design is done for three semiconductor types. Results show that GaN achieves lowest power losses while its heatsink size and volume is limited by the thermal properties of the GaN chip.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117038681","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697851
K. Varesi, M. Karimi, Paria Kargar
A new step-up Cascaded Multi-Level Inverter (CMLI) has been proposed in this paper. The proposed basic 35-level topology is composed of 4 DC sources, 2 capacitors, 2 diodes and 12 switches. The sum of input DC sources is 10Vdc, where the peak output voltage is 17Vdc. So, the proposed basic topology can act a step-up inverter with the gain of about 1.7. The proposed basic topology has simple structure. Since the voltage balancing of capacitors are done naturally, the control of proposed topology is also simple. The number of levels per number of components (such as DC sources, switches, gate driver circuits, diodes and capacitors) in proposed basic topology is higher than other similar converters. In this paper, the proposed basic topology has been introduced and its operational principles have been presented. Then, it has been compared with recently presented novel structures. The comparison results validate the advantages of proposed basic topology. Then, the proposed basic topology has been extended to act as a Multi-Level inverter. Finally, the appropriate performance of proposed basic topology has been verified by simulation results, extracted from PSCAD/EMTDC software.
{"title":"A New Basic Step-Up Cascaded 35-Level Topology Extendable To Higher Number of Levels","authors":"K. Varesi, M. Karimi, Paria Kargar","doi":"10.1109/PEDSTC.2019.8697851","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697851","url":null,"abstract":"A new step-up Cascaded Multi-Level Inverter (CMLI) has been proposed in this paper. The proposed basic 35-level topology is composed of 4 DC sources, 2 capacitors, 2 diodes and 12 switches. The sum of input DC sources is 10Vdc, where the peak output voltage is 17Vdc. So, the proposed basic topology can act a step-up inverter with the gain of about 1.7. The proposed basic topology has simple structure. Since the voltage balancing of capacitors are done naturally, the control of proposed topology is also simple. The number of levels per number of components (such as DC sources, switches, gate driver circuits, diodes and capacitors) in proposed basic topology is higher than other similar converters. In this paper, the proposed basic topology has been introduced and its operational principles have been presented. Then, it has been compared with recently presented novel structures. The comparison results validate the advantages of proposed basic topology. Then, the proposed basic topology has been extended to act as a Multi-Level inverter. Finally, the appropriate performance of proposed basic topology has been verified by simulation results, extracted from PSCAD/EMTDC software.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"224 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117005563","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 : 2019-02-01DOI: 10.1109/pedstc.2019.8697287
{"title":"PEDSTC 2019 Cover Page","authors":"","doi":"10.1109/pedstc.2019.8697287","DOIUrl":"https://doi.org/10.1109/pedstc.2019.8697287","url":null,"abstract":"","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121579898","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697807
Hamid Hefaz, E. Afjei, Masoud Ardestani
Rotor structure Design complexity in synchronous reluctance machines has been one of the major challenges in decades. In this paper, an analysis of sensitivity for the rotor geometry parameters of a 6-pole external-rotor synchronous reluctance motor has been carried out. The d axis & q axis inductances have significant importance on simultaneously achieve maximum developed torque & low torque ripple. Many magnetically accurate Finite element analyses have been conducted to characterise the electromagnetic motor performance. The analyses confirm the validity of the torque & power factor expressions for the proposed external rotor synchronous reluctance motor.
{"title":"Sensitivity Analysis of Rotor Geometry for External-Rotor Synchronous Reluctance Motor Using Finite Element Method","authors":"Hamid Hefaz, E. Afjei, Masoud Ardestani","doi":"10.1109/PEDSTC.2019.8697807","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697807","url":null,"abstract":"Rotor structure Design complexity in synchronous reluctance machines has been one of the major challenges in decades. In this paper, an analysis of sensitivity for the rotor geometry parameters of a 6-pole external-rotor synchronous reluctance motor has been carried out. The d axis & q axis inductances have significant importance on simultaneously achieve maximum developed torque & low torque ripple. Many magnetically accurate Finite element analyses have been conducted to characterise the electromagnetic motor performance. The analyses confirm the validity of the torque & power factor expressions for the proposed external rotor synchronous reluctance motor.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121600204","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697614
Mohammad Rastegar, M. Saradarzadeh, S. Farhangi
Sympathy phenomenon is caused by the interaction between the transformers. Inrush current of transformers, especially in long transmission lines is unavoidable that can be as high as 10 times of the transformer rated current lasting for a few cycles or more depending on R/L in the primary side of the transformer. This inrush current causes the saturation of available parallel transformers in the line. This kind of magnetizing transient is called sympathy. Sympathy has many effects on the power system like appearance of unsymmetrical voltage sag, transient harmonics components and overvoltage, which disrupt the operation of differential relays and also coordination of transformer overcurrent relays and affects the whole protection system. In this paper, a new lateral application is proposed for a Static Synchronous Series Compensator (SSSC) to overcome the inrush current and consequently tackles the sympathy phenomena. The proposed control method detects the inrush current in the line by the Sympathy Detection Unit and determines the mode of operation to inject the high inductance series to the line. It operates independently from the switching-on instance. An 11-level Cascaded H-bridge converter is placed in series with the line acting as SSSC in the normal condition and a high impedance during energizing transformers. The simulation results show the feasibility and the proper dynamic of the proposed control method in limiting the inrush current and avoiding the sympathy for the connected transformers.
{"title":"A New Control Method to Overcome Sympathy Between Transformers using SSSC","authors":"Mohammad Rastegar, M. Saradarzadeh, S. Farhangi","doi":"10.1109/PEDSTC.2019.8697614","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697614","url":null,"abstract":"Sympathy phenomenon is caused by the interaction between the transformers. Inrush current of transformers, especially in long transmission lines is unavoidable that can be as high as 10 times of the transformer rated current lasting for a few cycles or more depending on R/L in the primary side of the transformer. This inrush current causes the saturation of available parallel transformers in the line. This kind of magnetizing transient is called sympathy. Sympathy has many effects on the power system like appearance of unsymmetrical voltage sag, transient harmonics components and overvoltage, which disrupt the operation of differential relays and also coordination of transformer overcurrent relays and affects the whole protection system. In this paper, a new lateral application is proposed for a Static Synchronous Series Compensator (SSSC) to overcome the inrush current and consequently tackles the sympathy phenomena. The proposed control method detects the inrush current in the line by the Sympathy Detection Unit and determines the mode of operation to inject the high inductance series to the line. It operates independently from the switching-on instance. An 11-level Cascaded H-bridge converter is placed in series with the line acting as SSSC in the normal condition and a high impedance during energizing transformers. The simulation results show the feasibility and the proper dynamic of the proposed control method in limiting the inrush current and avoiding the sympathy for the connected transformers.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126830388","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697268
Shahin Sabour, D. Nazarpour, S. Golshannavaz, R. Choupan
In this research, two novel topologies made up of combined customary H-bridge and quasi-resonant switched-capacitor inverter units are introduced for multi-level inverters. Compared to conventional topologies, the proposed topologies need a lower quantity of dc voltage sources and switches and smaller system size and cost. Furthermore, the proposed topologies do not require a transformer to enhance the input voltage. In the proposed topologies, the series-connected capacitors divide the voltage input equally, and the desired voltage may be attained via increasing the basic unit. With respect to the frequency of switching and the consequent loss, fundamental frequency modulation is preferable. In order to simultaneously prevent the current spikes due to the instantaneous parallel connection between the input source and the capacitors connected in series, reduce the capacitance, decrease the electromagnetic interference, and improve capacitor lifetime, the quasi-resonance method is utilized. To demonstrate the correct working of the proposed topologies, simulation results corresponding to 13-level and 17-level single-phase inverters are provided.
{"title":"Cascaded Multilevel Inverter Using Quasi Resonant Switched Capacitor Units","authors":"Shahin Sabour, D. Nazarpour, S. Golshannavaz, R. Choupan","doi":"10.1109/PEDSTC.2019.8697268","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697268","url":null,"abstract":"In this research, two novel topologies made up of combined customary H-bridge and quasi-resonant switched-capacitor inverter units are introduced for multi-level inverters. Compared to conventional topologies, the proposed topologies need a lower quantity of dc voltage sources and switches and smaller system size and cost. Furthermore, the proposed topologies do not require a transformer to enhance the input voltage. In the proposed topologies, the series-connected capacitors divide the voltage input equally, and the desired voltage may be attained via increasing the basic unit. With respect to the frequency of switching and the consequent loss, fundamental frequency modulation is preferable. In order to simultaneously prevent the current spikes due to the instantaneous parallel connection between the input source and the capacitors connected in series, reduce the capacitance, decrease the electromagnetic interference, and improve capacitor lifetime, the quasi-resonance method is utilized. To demonstrate the correct working of the proposed topologies, simulation results corresponding to 13-level and 17-level single-phase inverters are provided.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"55 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132444376","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 : 2019-02-01DOI: 10.1109/PEDSTC.2019.8697547
Morteza Dezhbord, Milad Babalou, Vafa Marzang, Peyman Alavi, S. Hosseini, S. Mohammadi
In this paper, a new high step-up three-port structure using one PV panel and a battery as a storage element is proposed. In this proposed structure, three power switches, one single inductor and one coupled inductor are used. The gain of voltage for the presented topology is higher than conventional three-port converters which is referred in this paper. Using one unidirectional and one bidirectional inputs develop the proposed topology as a compatible candidate for hybrid power system. Controlling state of charge (SOC) for battery, and regulating the voltage of output can be achieved by adjusting duty cycles of switches. Also, the capability of supplying the load and either charging or discharging of the storage element is provided by input source. In addition, the capability of supplying the load without PV source is provided by battery. The analysis of steady-state condition in the proposed converter is discussed completely. Finally, the validity of the presented structure is verified by simulation results.
{"title":"A new High Step-up Three-Port DC-DC Structure for Hybrid PV/Battery Energy Systems","authors":"Morteza Dezhbord, Milad Babalou, Vafa Marzang, Peyman Alavi, S. Hosseini, S. Mohammadi","doi":"10.1109/PEDSTC.2019.8697547","DOIUrl":"https://doi.org/10.1109/PEDSTC.2019.8697547","url":null,"abstract":"In this paper, a new high step-up three-port structure using one PV panel and a battery as a storage element is proposed. In this proposed structure, three power switches, one single inductor and one coupled inductor are used. The gain of voltage for the presented topology is higher than conventional three-port converters which is referred in this paper. Using one unidirectional and one bidirectional inputs develop the proposed topology as a compatible candidate for hybrid power system. Controlling state of charge (SOC) for battery, and regulating the voltage of output can be achieved by adjusting duty cycles of switches. Also, the capability of supplying the load and either charging or discharging of the storage element is provided by input source. In addition, the capability of supplying the load without PV source is provided by battery. The analysis of steady-state condition in the proposed converter is discussed completely. Finally, the validity of the presented structure is verified by simulation results.","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134174984","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 : 2019-02-01DOI: 10.1109/pedstc.2019.8697736
{"title":"PEDSTC 2019 Copyright Page","authors":"","doi":"10.1109/pedstc.2019.8697736","DOIUrl":"https://doi.org/10.1109/pedstc.2019.8697736","url":null,"abstract":"","PeriodicalId":296229,"journal":{"name":"2019 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114077073","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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