Pub Date : 1990-06-11DOI: 10.1109/PESC.1990.131193
Byungcho Choi, B. Cho, R. Ridley, F. C. Lee
A systematic control-loop design procedure for a multimodule converter system for high-current, low-voltage applications is presented. A small-signal model of the system is derived using the PWM (pulse width modulation) switch model and the small-signal model of the current mode control. The small-signal model for the multimodule converter system is simplified to a equivalent single-module model. The control-loop design is implemented using the single-module model. A three-loop control strategy for the multimodule converter system with a secondary output filter is developed. Significant improvements of small-signal performance and module-failure response are achieved using additional feedback from the intermediate filter stage. The small-signal analysis of the three-loop controlled converter is performed, focusing on the effects of the local voltage feedback on the closed-loop performance of the system. It is shown that local voltage feedback minimizes any detrimental effect of the resonance between the power stage filter of each converter module and the common output filter.<>
{"title":"Control strategy for multi-module parallel converter system","authors":"Byungcho Choi, B. Cho, R. Ridley, F. C. Lee","doi":"10.1109/PESC.1990.131193","DOIUrl":"https://doi.org/10.1109/PESC.1990.131193","url":null,"abstract":"A systematic control-loop design procedure for a multimodule converter system for high-current, low-voltage applications is presented. A small-signal model of the system is derived using the PWM (pulse width modulation) switch model and the small-signal model of the current mode control. The small-signal model for the multimodule converter system is simplified to a equivalent single-module model. The control-loop design is implemented using the single-module model. A three-loop control strategy for the multimodule converter system with a secondary output filter is developed. Significant improvements of small-signal performance and module-failure response are achieved using additional feedback from the intermediate filter stage. The small-signal analysis of the three-loop controlled converter is performed, focusing on the effects of the local voltage feedback on the closed-loop performance of the system. It is shown that local voltage feedback minimizes any detrimental effect of the resonance between the power stage filter of each converter module and the common output filter.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121788890","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 : 1990-06-11DOI: 10.1109/PESC.1990.131262
M. H. Kheraluwala, Donald W. Novotny, Deepakraj M. Divan
Various design considerations for high-power (multikilowatt), high-frequency transformers for DC-DC power converters are investigated. Although Ferrite (PC40) is lossier than Permalloy80 (0.5 mil) at the frequencies of interest (25-50 kHz) the use of the former is justified on the basis of cost, weight, and wide ranges of shapes. The influence of the leakage flux distribution in the window region on the copper losses has been demonstrated for various conventional winding arrangements. However, it is seen that in conventionally wound transformers a considerable amount of leakage flux enters the core, resulting in localized core saturation and hot-spots. This becomes a very critical issue for high-power, high-frequency transformers. Coaxially wound transformers are seen to be a viable alternative, in that the leakage flux is contained with the interwinding space, with very little or none of it permeating the core. Such transformers can also realize multiple benefits of a low distributed and controllable leakage inductance, robust construction, low electromechanical forces, and low core and copper losses. Test results on two coaxially wound transformers with different tube geometries, designed for 50 kW, 50 kHz, primary voltage of 200 V, and secondary voltage of 1000 V (two windings), are presented. Finally the concept of coaxial winding technique for three-phase transformers is also presented.<>
{"title":"Design considerations for high power high frequency transformers","authors":"M. H. Kheraluwala, Donald W. Novotny, Deepakraj M. Divan","doi":"10.1109/PESC.1990.131262","DOIUrl":"https://doi.org/10.1109/PESC.1990.131262","url":null,"abstract":"Various design considerations for high-power (multikilowatt), high-frequency transformers for DC-DC power converters are investigated. Although Ferrite (PC40) is lossier than Permalloy80 (0.5 mil) at the frequencies of interest (25-50 kHz) the use of the former is justified on the basis of cost, weight, and wide ranges of shapes. The influence of the leakage flux distribution in the window region on the copper losses has been demonstrated for various conventional winding arrangements. However, it is seen that in conventionally wound transformers a considerable amount of leakage flux enters the core, resulting in localized core saturation and hot-spots. This becomes a very critical issue for high-power, high-frequency transformers. Coaxially wound transformers are seen to be a viable alternative, in that the leakage flux is contained with the interwinding space, with very little or none of it permeating the core. Such transformers can also realize multiple benefits of a low distributed and controllable leakage inductance, robust construction, low electromechanical forces, and low core and copper losses. Test results on two coaxially wound transformers with different tube geometries, designed for 50 kW, 50 kHz, primary voltage of 200 V, and secondary voltage of 1000 V (two windings), are presented. Finally the concept of coaxial winding technique for three-phase transformers is also presented.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128714616","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 : 1990-06-11DOI: 10.1109/PESC.1990.131230
R. Nilssen, O. Mo
A special-purpose program for long-term digital simulation of power electronic circuits, KREAN, is presented. Particular attention is given to simple device modeling for long-term simulation, solution of stiff power electronic circuits (simultaneously having large and small time constants), solution of large sparse circuit matrices, and handling of discontinuities in switched power electronic circuits. This work has been undertaken to present an attractive alternative to general-purpose programs like SPICE and EMTP.<>
{"title":"KREAN, a new simulation program for power electronic circuits","authors":"R. Nilssen, O. Mo","doi":"10.1109/PESC.1990.131230","DOIUrl":"https://doi.org/10.1109/PESC.1990.131230","url":null,"abstract":"A special-purpose program for long-term digital simulation of power electronic circuits, KREAN, is presented. Particular attention is given to simple device modeling for long-term simulation, solution of stiff power electronic circuits (simultaneously having large and small time constants), solution of large sparse circuit matrices, and handling of discontinuities in switched power electronic circuits. This work has been undertaken to present an attractive alternative to general-purpose programs like SPICE and EMTP.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116742820","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 : 1990-06-11DOI: 10.1109/PESC.1990.131214
C.L. Tsay, R. Fischl, J. Schwartzenberg, H. Kan, J. Barrow
The authors present GTO (gate turn off thyristor) model which simulates both the static negative differential resistance characteristics and the dynamic switching characteristics. The model consists of parallel connection of two-transistor, three-resistor (2T-3R) circuits which make it compatible with the SPICE program. An experimental validation test shows that the accuracy of the model can be improved by increasing the number of 2T-3R cells.<>
{"title":"A high power circuit model for the gate turn off thyristor","authors":"C.L. Tsay, R. Fischl, J. Schwartzenberg, H. Kan, J. Barrow","doi":"10.1109/PESC.1990.131214","DOIUrl":"https://doi.org/10.1109/PESC.1990.131214","url":null,"abstract":"The authors present GTO (gate turn off thyristor) model which simulates both the static negative differential resistance characteristics and the dynamic switching characteristics. The model consists of parallel connection of two-transistor, three-resistor (2T-3R) circuits which make it compatible with the SPICE program. An experimental validation test shows that the accuracy of the model can be improved by increasing the number of 2T-3R cells.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126408606","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 : 1990-06-11DOI: 10.1109/PESC.1990.131176
A. Kislovski
The small-signal, low-frequency control-voltage-to-output voltage transfer function of a buck cell utilizing the PWM (pulse width modulation) conductance control principle is derived, and its dependence on different circuit parameters is established. A numerical application shows close agreement with previously published data. The results obtained are used to compare the PWM conductance controller to its current-mode control counterpart utilizing a linear compensating ramp. Precise and comprehensive indications are given as to how the analysis applied can be used to investigate the dynamic loading imposed by the PWM conductance control cells on their input filters. The goal is to demonstrate the simplicity of the PWM conductance control principle's dynamic analysis when the method of characteristic coefficients is applied.<>
{"title":"Small-signal, low-frequency analysis of a buck type PWM conductance controller","authors":"A. Kislovski","doi":"10.1109/PESC.1990.131176","DOIUrl":"https://doi.org/10.1109/PESC.1990.131176","url":null,"abstract":"The small-signal, low-frequency control-voltage-to-output voltage transfer function of a buck cell utilizing the PWM (pulse width modulation) conductance control principle is derived, and its dependence on different circuit parameters is established. A numerical application shows close agreement with previously published data. The results obtained are used to compare the PWM conductance controller to its current-mode control counterpart utilizing a linear compensating ramp. Precise and comprehensive indications are given as to how the analysis applied can be used to investigate the dynamic loading imposed by the PWM conductance control cells on their input filters. The goal is to demonstrate the simplicity of the PWM conductance control principle's dynamic analysis when the method of characteristic coefficients is applied.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129348781","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 : 1990-06-11DOI: 10.1109/PESC.1990.131276
A. Capel, C. Peyrotte, J. Marpinard, R. Rodriguez
A state variable feedback controller combining large signal and current mode control is analyzed and detailed for a radar pulsed power supply for space applications. This controller, called the current control mode state feedback controller, combines sampling frequency and bidirectional current flow buck cell. The typical features of the current control modulator are maintained, as the principle is based on the prediction of the inductance peak current, but the conventional error signal amplifier is replaced by a linear electrical network generating from the power cell parameters an adequate command signal. A typical radar power supply delivering 40 W of pulsed power is presented; predicted time domain results are validated against breadboard performances.<>
{"title":"Large signal feedback control and high sampling frequency combine for an efficient radar power supply for space applications","authors":"A. Capel, C. Peyrotte, J. Marpinard, R. Rodriguez","doi":"10.1109/PESC.1990.131276","DOIUrl":"https://doi.org/10.1109/PESC.1990.131276","url":null,"abstract":"A state variable feedback controller combining large signal and current mode control is analyzed and detailed for a radar pulsed power supply for space applications. This controller, called the current control mode state feedback controller, combines sampling frequency and bidirectional current flow buck cell. The typical features of the current control modulator are maintained, as the principle is based on the prediction of the inductance peak current, but the conventional error signal amplifier is replaced by a linear electrical network generating from the power cell parameters an adequate command signal. A typical radar power supply delivering 40 W of pulsed power is presented; predicted time domain results are validated against breadboard performances.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115188710","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 : 1990-06-11DOI: 10.1109/PESC.1990.131235
T. Ninomiya, T. Higashi, M. Nakahara, K. Fujimoto, K. Harada
A full-wave voltage-mode resonant forward-type power converter with a transformer is proposed, and its basic characteristics are revealed by analysis and experiment. This converter features simplicity of circuit configuration, low output impedance, small variation of switching frequency to regulate the output voltage, high stability, and availability of multiple outputs. For the multioutput configuration, steady-state error on the cross-regulated output voltage is investigated, and it is clarified that this cross-regulation error depends on the parasitic resistance and the leakage inductance of the transformer. The mechanism of cross-regulation error due to each element is discussed.<>
{"title":"Full-wave voltage-mode resonant converter with multiple outputs","authors":"T. Ninomiya, T. Higashi, M. Nakahara, K. Fujimoto, K. Harada","doi":"10.1109/PESC.1990.131235","DOIUrl":"https://doi.org/10.1109/PESC.1990.131235","url":null,"abstract":"A full-wave voltage-mode resonant forward-type power converter with a transformer is proposed, and its basic characteristics are revealed by analysis and experiment. This converter features simplicity of circuit configuration, low output impedance, small variation of switching frequency to regulate the output voltage, high stability, and availability of multiple outputs. For the multioutput configuration, steady-state error on the cross-regulated output voltage is investigated, and it is clarified that this cross-regulation error depends on the parasitic resistance and the leakage inductance of the transformer. The mechanism of cross-regulation error due to each element is discussed.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"63 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120839337","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 : 1990-06-11DOI: 10.1109/PESC.1990.131250
R. D. De Doncker, F. Profumo, M. Pastorelli
The universal field-oriented (UFO) controller is used to control the induction motor torque and airgap flux independently of each other. In this work, the direct UFO control is realized by sensing the airgap flux using center taps on two machine windings. Moreover, an adaptive control scheme that accomplishes a continuous and automatic tuning of the rotor time constant of the field-oriented controller whenever the drive operates in the direct field orientation mode is proposed. In addition, at low invertor frequencies, the UFO controller switches over to the indirect field orientation mode in which the rotor time constant is frozen to the last tuned value of the previous direct field orientation mode. At steady state and elevated speeds the induction motor servo drive has no detuning errors when operating under direct field orientation, while at low speeds the indirect field orientation mode exhibits minimal errors. The latter expands the use of the high-performance induction motor drive up to standstill. The proposed field-oriented controller can be realized at minimal cost in AC servomotor drives requiring motion control or accurate speed control.<>
{"title":"Self tuning of induction motor servo drives using the universal field oriented controller","authors":"R. D. De Doncker, F. Profumo, M. Pastorelli","doi":"10.1109/PESC.1990.131250","DOIUrl":"https://doi.org/10.1109/PESC.1990.131250","url":null,"abstract":"The universal field-oriented (UFO) controller is used to control the induction motor torque and airgap flux independently of each other. In this work, the direct UFO control is realized by sensing the airgap flux using center taps on two machine windings. Moreover, an adaptive control scheme that accomplishes a continuous and automatic tuning of the rotor time constant of the field-oriented controller whenever the drive operates in the direct field orientation mode is proposed. In addition, at low invertor frequencies, the UFO controller switches over to the indirect field orientation mode in which the rotor time constant is frozen to the last tuned value of the previous direct field orientation mode. At steady state and elevated speeds the induction motor servo drive has no detuning errors when operating under direct field orientation, while at low speeds the indirect field orientation mode exhibits minimal errors. The latter expands the use of the high-performance induction motor drive up to standstill. The proposed field-oriented controller can be realized at minimal cost in AC servomotor drives requiring motion control or accurate speed control.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123196704","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 : 1990-06-11DOI: 10.1109/PESC.1990.131259
M. Boost, P. Ziogas
An audible noise reduction for medium power inverters which involves the application of a specialized inverter PWM (pulse width modulated) technique combined with a preregulation stage offering an improved inverter output voltage spectrum is proposed. Consequently, inverter switching losses are kept low, while the dominant harmonic generated should not contribute to audible noise measured. Thus, inverter stages previously limited by switching losses can process larger power levels. The carrier-based PWM technique presented here has its first harmonic family at 2.5 times the switching frequency. The technique allows base frequency changes identical to that of sine PWM, yet offers a 15% higher voltage gain. Since the technique is most effective at full modulation index, medium power DC-DC converters capable of inverter input regulation are discussed. Selected experimental results are presented to validate the PWM technique, and a high-frequency preregulation stage is proposed for applications requiring galvanic isolation between source and load.<>
{"title":"Audible noise reduction for medium power inverters","authors":"M. Boost, P. Ziogas","doi":"10.1109/PESC.1990.131259","DOIUrl":"https://doi.org/10.1109/PESC.1990.131259","url":null,"abstract":"An audible noise reduction for medium power inverters which involves the application of a specialized inverter PWM (pulse width modulated) technique combined with a preregulation stage offering an improved inverter output voltage spectrum is proposed. Consequently, inverter switching losses are kept low, while the dominant harmonic generated should not contribute to audible noise measured. Thus, inverter stages previously limited by switching losses can process larger power levels. The carrier-based PWM technique presented here has its first harmonic family at 2.5 times the switching frequency. The technique allows base frequency changes identical to that of sine PWM, yet offers a 15% higher voltage gain. Since the technique is most effective at full modulation index, medium power DC-DC converters capable of inverter input regulation are discussed. Selected experimental results are presented to validate the PWM technique, and a high-frequency preregulation stage is proposed for applications requiring galvanic isolation between source and load.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123561991","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 : 1990-06-11DOI: 10.1109/PESC.1990.131216
R. Dutta, A. Rothwarf
An analysis of a high-voltage GTO (gate turn-off) thyristor structure with a double-layered n base is presented. From integration of Poisson's equation, an expression for the forward blocking voltage at the onset of avalanche breakdown is obtained. Simple design criteria are developed to calculate the optimal thickness and doping density of the n base of a conventional p-n-p-n structure designed for a specific voltage blocking capability. The same principle is applied to design for the doping densities and thicknesses of the high-resistivity region and the buffer layer of the p-i-n GTO structure. The forward blocking voltage as well as the on state voltage (at a current density of 300 A-cm/sup -2/) is predicted for a wide range of base layer thicknesses and doping densities to illustrate the available tradeoff options.<>
分析了一种具有双层n基的高压栅关断晶闸管结构。通过对泊松方程的积分，得到雪崩击穿发生时的正向阻断电压表达式。我们开发了简单的设计准则来计算传统的p-n-p-n结构的n基的最佳厚度和掺杂密度，这些结构设计用于特定的电压阻断能力。同样的原理也适用于设计高电阻区和p-i-n GTO结构缓冲层的掺杂密度和厚度。正向阻断电压以及导通状态电压(电流密度为300 a -cm/sup -2/)被预测为广泛的基层厚度和掺杂密度，以说明可用的权衡选项。
{"title":"Optimal design of two layered n base in a gate turn-off thyristor","authors":"R. Dutta, A. Rothwarf","doi":"10.1109/PESC.1990.131216","DOIUrl":"https://doi.org/10.1109/PESC.1990.131216","url":null,"abstract":"An analysis of a high-voltage GTO (gate turn-off) thyristor structure with a double-layered n base is presented. From integration of Poisson's equation, an expression for the forward blocking voltage at the onset of avalanche breakdown is obtained. Simple design criteria are developed to calculate the optimal thickness and doping density of the n base of a conventional p-n-p-n structure designed for a specific voltage blocking capability. The same principle is applied to design for the doping densities and thicknesses of the high-resistivity region and the buffer layer of the p-i-n GTO structure. The forward blocking voltage as well as the on state voltage (at a current density of 300 A-cm/sup -2/) is predicted for a wide range of base layer thicknesses and doping densities to illustrate the available tradeoff options.<<ETX>>","PeriodicalId":330807,"journal":{"name":"21st Annual IEEE Conference on Power Electronics Specialists","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121427264","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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