Pub Date : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213813
Seung-Woo Baek, Sujin Choi, Hag-Wone Kim, Kwan-Yuhl Cho, Kyung-Ahn Kwon
This study proposes a switching control strategy to reduce overshoot caused by load variations in a bidirectional Cascade buck-boost converter operating in boost mode. To achieve this, the cause of overshoot that occurs when the load decreases is analyzed, which is found to be due to the magnitude of the voltage applied to the inductor, which is the difference between the input and output voltages. The proposed switching control strategy ensures that only the output voltage is applied to the inductor. The proposed method reduces overshoot by about 55%, from 42V to 19V, and this has been verified through simulation.
{"title":"Output Voltage Overshoot Reduction Techniques for Cascade Buck-Boost Converters","authors":"Seung-Woo Baek, Sujin Choi, Hag-Wone Kim, Kwan-Yuhl Cho, Kyung-Ahn Kwon","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213813","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213813","url":null,"abstract":"This study proposes a switching control strategy to reduce overshoot caused by load variations in a bidirectional Cascade buck-boost converter operating in boost mode. To achieve this, the cause of overshoot that occurs when the load decreases is analyzed, which is found to be due to the magnitude of the voltage applied to the inductor, which is the difference between the input and output voltages. The proposed switching control strategy ensures that only the output voltage is applied to the inductor. The proposed method reduces overshoot by about 55%, from 42V to 19V, and this has been verified through simulation.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129080776","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213583
Cheonsu Park, S. Doki
When one inverter drives both motors, the system efficiency deteriorates if both motors have different loads. Moreover, even if their loads are the same, the system efficiency would also deteriorate if the parameters of both motors are different. To address this issue, this paper proposes optimal current control methods for both different motors using a single inverter.
{"title":"Optimal Current Control Methods for Dual-Parallel-SPMSM with Different Parameters Using a Single Inverter","authors":"Cheonsu Park, S. Doki","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213583","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213583","url":null,"abstract":"When one inverter drives both motors, the system efficiency deteriorates if both motors have different loads. Moreover, even if their loads are the same, the system efficiency would also deteriorate if the parameters of both motors are different. To address this issue, this paper proposes optimal current control methods for both different motors using a single inverter.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129209232","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 : 2023-05-22DOI: 10.23919/icpe2023-ecceasia54778.2023.10213808
Jeong-Eon Park, Taewoo Kim, Seung-Hyun Choi, Jae-In Lee, G. Moon
An asymmetric half-bridge (AHB) converter is commonly utilized in low-power systems. However, due to its asymmetric operation, the AHB converter suffers from degraded efficiency. To improve this drawback, several approaches have proposed a new secondary rectifier structure. Among various rectifier structures, the series capacitor rectifier (SCR) structure has a strong advantage such as the zero dc-offset current and balanced average current of diodes. However, it suffers from weakened energy for zero-voltage switching (ZVS) under light load conditions. In this paper, simple synchronous rectifier (SR) switch control is proposed. The strong point of the proposed converter is that it can simply integrate two different rectifier structures by replacing two diodes with two SR switches. Consequently, the proposed converter can achieve higher efficiency than previous AHB converters. The feasibility of the proposed converter is verified with a 48 V/400 W prototype converter.
{"title":"High Efficiency of Asymmetric Half-Bridge Converter with Simple SR Switch Control under Light Load Condition","authors":"Jeong-Eon Park, Taewoo Kim, Seung-Hyun Choi, Jae-In Lee, G. Moon","doi":"10.23919/icpe2023-ecceasia54778.2023.10213808","DOIUrl":"https://doi.org/10.23919/icpe2023-ecceasia54778.2023.10213808","url":null,"abstract":"An asymmetric half-bridge (AHB) converter is commonly utilized in low-power systems. However, due to its asymmetric operation, the AHB converter suffers from degraded efficiency. To improve this drawback, several approaches have proposed a new secondary rectifier structure. Among various rectifier structures, the series capacitor rectifier (SCR) structure has a strong advantage such as the zero dc-offset current and balanced average current of diodes. However, it suffers from weakened energy for zero-voltage switching (ZVS) under light load conditions. In this paper, simple synchronous rectifier (SR) switch control is proposed. The strong point of the proposed converter is that it can simply integrate two different rectifier structures by replacing two diodes with two SR switches. Consequently, the proposed converter can achieve higher efficiency than previous AHB converters. The feasibility of the proposed converter is verified with a 48 V/400 W prototype converter.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"159 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130579644","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213758
Jong-Uk Yang, Gi-Young Lee, Rae-Young Kim
This paper describes the research conducted on the design method of HFT (High Frequency Transformer) in high frequency application. The proposed design method accurately predicts inductance based on magnetic equivalent model considering MPL (Magnetic Path Length) and Fringing effect. Here, the multi-objective optimization technique is applied to optimize the HFT design. The effectiveness of the proposed method is verified through an experiment of a 500W LLC resonant converter.
{"title":"Transformer Design Considering Fringing Effect for High Frequency Application","authors":"Jong-Uk Yang, Gi-Young Lee, Rae-Young Kim","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213758","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213758","url":null,"abstract":"This paper describes the research conducted on the design method of HFT (High Frequency Transformer) in high frequency application. The proposed design method accurately predicts inductance based on magnetic equivalent model considering MPL (Magnetic Path Length) and Fringing effect. Here, the multi-objective optimization technique is applied to optimize the HFT design. The effectiveness of the proposed method is verified through an experiment of a 500W LLC resonant converter.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"32 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123663032","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213553
Christoph Lüdecke, Niklas Fritz, R. D. De Doncker
In this work, a gate driver is presented that allows to balance the temperature of parallel-connected silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) with a closed-loop control. In conventional gate drivers, switching events are often slowed down to avoid unevenly distributed losses of parallel-connected SiC MOSFETs. Due to the reduced switching speed, wide-bandgap (WBG) semiconductor devices are not fully utilized. The presented gate driver selectively delays the individual gate signals of the parallel-connected MOSFETs to influence the switching losses. To balance the temperature of the MOSFETs during operation, a closed-loop control is designed and verified by measurements. The presented gate driver thus enables a balanced stress of parallel-connected MOSFETs and a uniform aging of the MOSFETs. Therefore, the potential of parallel-connected WBG semiconductor devices can be better utilized and a derating of the system is avoided.
{"title":"Design of a Closed-Loop Control to Balance Unequal Temperature Distributions of Parallel-Connected SiC MOSFETs","authors":"Christoph Lüdecke, Niklas Fritz, R. D. De Doncker","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213553","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213553","url":null,"abstract":"In this work, a gate driver is presented that allows to balance the temperature of parallel-connected silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) with a closed-loop control. In conventional gate drivers, switching events are often slowed down to avoid unevenly distributed losses of parallel-connected SiC MOSFETs. Due to the reduced switching speed, wide-bandgap (WBG) semiconductor devices are not fully utilized. The presented gate driver selectively delays the individual gate signals of the parallel-connected MOSFETs to influence the switching losses. To balance the temperature of the MOSFETs during operation, a closed-loop control is designed and verified by measurements. The presented gate driver thus enables a balanced stress of parallel-connected MOSFETs and a uniform aging of the MOSFETs. Therefore, the potential of parallel-connected WBG semiconductor devices can be better utilized and a derating of the system is avoided.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116286062","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213775
T. Yamahigashi, J. Shimura, K. Shibuya, Y.-H. Wu, K. Shigematsu, T. Hosotani, J. Kuromi, J. Imaoka, M. Yamamoto
An equivalent circuit model of lithium-ion batteries which has a nonlinear resistor governed by Butler-Volmer’s equation and a constant phase element was investigated. The current dependence of the real battery could be reproduced well by the contribution of the nonlinear resistor, and the transient response of voltage could be reproduced well by the contribution of the constant phase element.
{"title":"Modeling of Lithium-Ion Batteries with Constant Phase Element and Butler-Volmer’s Equation","authors":"T. Yamahigashi, J. Shimura, K. Shibuya, Y.-H. Wu, K. Shigematsu, T. Hosotani, J. Kuromi, J. Imaoka, M. Yamamoto","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213775","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213775","url":null,"abstract":"An equivalent circuit model of lithium-ion batteries which has a nonlinear resistor governed by Butler-Volmer’s equation and a constant phase element was investigated. The current dependence of the real battery could be reproduced well by the contribution of the nonlinear resistor, and the transient response of voltage could be reproduced well by the contribution of the constant phase element.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126396219","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213752
Qilin Peng, Jiajun Yang, Sandro Guenter, G. Buticchi, N. Tan, P. Wheeler
As the penetration rate of renewable generation has risen in the last decades, power electronics converters are becoming more and more dominant in modern electrical power systems. Three-phase grid-connected converters provide an interface between the utility grid and distributed power sources such as photovoltaic (PV), wind turbines, energy storage systems, etc. Synchronization of these converters are always achieved through Synchronous Reference Frame (SRF). Thus, impedance-based stability analysis under SRF becomes a powerful tool to assess the system stability and optimize the converter design. However, precise measurement of the system impedance can be a difficult task in practice, particularly for high-capacity converters. In this paper, a hardware-in-the-loop (HiL) platform is proposed for measurement of the SRF impedance. Consequently, the impedance of an Active Front End (AFE) converter is measured and compared with the analytical small-signal model. The results show that measurement with the proposed HiL setup provides a powerful and accurate solution for impedance measurement that precludes the need for complete hardware testing.
{"title":"HiL Platform for Synchronous Reference Frame Impedance Measurement and Stability Assessment of Three-Phase Power Electronics Systems","authors":"Qilin Peng, Jiajun Yang, Sandro Guenter, G. Buticchi, N. Tan, P. Wheeler","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213752","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213752","url":null,"abstract":"As the penetration rate of renewable generation has risen in the last decades, power electronics converters are becoming more and more dominant in modern electrical power systems. Three-phase grid-connected converters provide an interface between the utility grid and distributed power sources such as photovoltaic (PV), wind turbines, energy storage systems, etc. Synchronization of these converters are always achieved through Synchronous Reference Frame (SRF). Thus, impedance-based stability analysis under SRF becomes a powerful tool to assess the system stability and optimize the converter design. However, precise measurement of the system impedance can be a difficult task in practice, particularly for high-capacity converters. In this paper, a hardware-in-the-loop (HiL) platform is proposed for measurement of the SRF impedance. Consequently, the impedance of an Active Front End (AFE) converter is measured and compared with the analytical small-signal model. The results show that measurement with the proposed HiL setup provides a powerful and accurate solution for impedance measurement that precludes the need for complete hardware testing.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128018552","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 : 2023-05-22DOI: 10.23919/icpe2023-ecceasia54778.2023.10213532
Van-Dai Bui, Honnyong Cha, Thien-Dung Tran
The floating double boost converter (FBC), including two single boost converters, is a solution for fuel-cell and renewable energy applications. To reduce the inductor currents in the FBC converter, the interleaved boost converters (IBC) are used instead of single boost converters so that the four-phase floating interleaved boost converter (4P-FBC) is formed. However, it is well known that the IBC suffers a significant problem with the unbalanced inductor currents issue, leading to high input current ripple. This paper proposed a floating double series-capacitor boost (FSCB) converter to solve the problem. Moreover, the voltage gain is improved by more than double, and the input current ripple can be minimized. As a result, the proposed converter is suitable for new energy sources, such as fuel-cell and photovoltaic. A 1.6 kW prototype was built and tested to verify the performance of the proposed converter.
{"title":"High-gain Floating Double Series-capacitor Boost Converter","authors":"Van-Dai Bui, Honnyong Cha, Thien-Dung Tran","doi":"10.23919/icpe2023-ecceasia54778.2023.10213532","DOIUrl":"https://doi.org/10.23919/icpe2023-ecceasia54778.2023.10213532","url":null,"abstract":"The floating double boost converter (FBC), including two single boost converters, is a solution for fuel-cell and renewable energy applications. To reduce the inductor currents in the FBC converter, the interleaved boost converters (IBC) are used instead of single boost converters so that the four-phase floating interleaved boost converter (4P-FBC) is formed. However, it is well known that the IBC suffers a significant problem with the unbalanced inductor currents issue, leading to high input current ripple. This paper proposed a floating double series-capacitor boost (FSCB) converter to solve the problem. Moreover, the voltage gain is improved by more than double, and the input current ripple can be minimized. As a result, the proposed converter is suitable for new energy sources, such as fuel-cell and photovoltaic. A 1.6 kW prototype was built and tested to verify the performance of the proposed converter.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128027988","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213576
Keita Ohata, Koki Yamanokuchi, Jun-ichi Itoh
This paper proposes wireless distributed control with a fault-tolerant for a solid-state transformer (SST) in single-wire open fault. A voltage imbalance occurs at the input side of each cell in the SST when an open-phase fault occurs. The voltage imbalance causes overmodulation in the power factor correction (PFC) converter. The proposed method employs the current droop control as an autonomous distributed control to achieve the voltage balance of each cell and prevent overmodulation without communication among each cell. The proposed method reduces the imbalance of the input voltage among series-connected cells by up to 95% compared to the control without the current droop control. Moreover, continuous operation is achieved during single-wire open-phase faults.
{"title":"Wireless Distributed Control with Open-Phase Fault-Tolerance for Delta-Connected Three-Phase Three-Wire Solid-State Transformers","authors":"Keita Ohata, Koki Yamanokuchi, Jun-ichi Itoh","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213576","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213576","url":null,"abstract":"This paper proposes wireless distributed control with a fault-tolerant for a solid-state transformer (SST) in single-wire open fault. A voltage imbalance occurs at the input side of each cell in the SST when an open-phase fault occurs. The voltage imbalance causes overmodulation in the power factor correction (PFC) converter. The proposed method employs the current droop control as an autonomous distributed control to achieve the voltage balance of each cell and prevent overmodulation without communication among each cell. The proposed method reduces the imbalance of the input voltage among series-connected cells by up to 95% compared to the control without the current droop control. Moreover, continuous operation is achieved during single-wire open-phase faults.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128113213","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 : 2023-05-22DOI: 10.23919/ICPE2023-ECCEAsia54778.2023.10213472
J. Min, Heewon Choi, Y. Suh
This paper introduces auto bias electrical variable capacitor(EVC) with reduced active components and voltage, current stress that mitigated switch noise for 13.56MHz RF plasma process. The proposed circuit have a small volume and low cost of EVC by using a small number of active components for the variable operation of the electrical variable capacitor, and enables more effective use in high-power systems through low switch voltage and current stress. In addition, the RF component flowing through the switch is effectively blocked to increase the operational reliability of the switch. The proposed circuit can be effectively replaced in the impedance matching network of RF plasma systems that require high power and high reliability.
{"title":"Resonance Type Auto Bias Electrical Variable Capacitor with Improved Switch Reliability for 13.56MHz RF Plasma System","authors":"J. Min, Heewon Choi, Y. Suh","doi":"10.23919/ICPE2023-ECCEAsia54778.2023.10213472","DOIUrl":"https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213472","url":null,"abstract":"This paper introduces auto bias electrical variable capacitor(EVC) with reduced active components and voltage, current stress that mitigated switch noise for 13.56MHz RF plasma process. The proposed circuit have a small volume and low cost of EVC by using a small number of active components for the variable operation of the electrical variable capacitor, and enables more effective use in high-power systems through low switch voltage and current stress. In addition, the RF component flowing through the switch is effectively blocked to increase the operational reliability of the switch. The proposed circuit can be effectively replaced in the impedance matching network of RF plasma systems that require high power and high reliability.","PeriodicalId":151155,"journal":{"name":"2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125615295","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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