Pub Date : 2007-11-01DOI: 10.1109/PEDS.2007.4487773
H. Athab, P. Shadhu Khan
This paper proposes a simple low-cost modulating duty cycle analog controller to reduce line harmonics for high power factor boost rectifier. The proposed method eliminates the need for current sensing, and simultaneously offers the performance results comparable to those of continuous conduction mode (CCM) scheme. This scheme also maintains the simplicity comparable to that of discontinuous conduction (DCM). Only the output voltage and the rectified input voltage are monitored to vary the duty cycle of the boost switch within a line cycle so that the third-order harmonic, which is the lowest order harmonic (LOH) of the input current, is reduced. As a result, the total harmonic distortion (THD) of the line current as well as the input power factor is improved. The proposed method is developed for constant switching frequency boost rectifier. Simulation and experimental results are presented to verify the effectiveness of the proposed control method.
{"title":"A Simple Effective Duty Cycle Controller for High Power Factor Boost Rectifier","authors":"H. Athab, P. Shadhu Khan","doi":"10.1109/PEDS.2007.4487773","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487773","url":null,"abstract":"This paper proposes a simple low-cost modulating duty cycle analog controller to reduce line harmonics for high power factor boost rectifier. The proposed method eliminates the need for current sensing, and simultaneously offers the performance results comparable to those of continuous conduction mode (CCM) scheme. This scheme also maintains the simplicity comparable to that of discontinuous conduction (DCM). Only the output voltage and the rectified input voltage are monitored to vary the duty cycle of the boost switch within a line cycle so that the third-order harmonic, which is the lowest order harmonic (LOH) of the input current, is reduced. As a result, the total harmonic distortion (THD) of the line current as well as the input power factor is improved. The proposed method is developed for constant switching frequency boost rectifier. Simulation and experimental results are presented to verify the effectiveness of the proposed control method.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133711156","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487876
S. Wangsathitwong, S. Sirisumrannukul, S. Chatratana, W. Deleroi
This paper presents a control technique to reduce the effect of unbalanced voltages in the doubly fed induction generator (DFIG) in wind energy conversion systems. The unbalanced voltages cause negative effects to the DFIG such as torque pulsation and increased stator current. Based on the symmetrical component theory, the negative sequence of the stator voltage can be extracted from the three-phase stator voltage and fed to compensate the rotor voltage to reduce the unbalanced effect. The magnitude of the compensating negative sequence is calculated from the negative sequence of the stator voltage and rotor speed. The proposed method shows a promising result for reduction of torque and reactive power pulsations.
{"title":"Symmetrical Components-Based Control Technique of Doubly Fed Induction Generators under Unbalanced Voltages for Reduction of Torque and Reactive Power Pulsations","authors":"S. Wangsathitwong, S. Sirisumrannukul, S. Chatratana, W. Deleroi","doi":"10.1109/PEDS.2007.4487876","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487876","url":null,"abstract":"This paper presents a control technique to reduce the effect of unbalanced voltages in the doubly fed induction generator (DFIG) in wind energy conversion systems. The unbalanced voltages cause negative effects to the DFIG such as torque pulsation and increased stator current. Based on the symmetrical component theory, the negative sequence of the stator voltage can be extracted from the three-phase stator voltage and fed to compensate the rotor voltage to reduce the unbalanced effect. The magnitude of the compensating negative sequence is calculated from the negative sequence of the stator voltage and rotor speed. The proposed method shows a promising result for reduction of torque and reactive power pulsations.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132105510","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487932
M. T. Bina, S. Rahimzadeh
Modeling of STATCOM is conventionally performed in the time-domain. Amongst them, dq-theory is well-known in which state-space equations are used for the analysis. Power systems, however, use the frequency-domain information in phasor-related studies such as load flow analysis. Because time-domain models of FACTS controllers cannot be directly applied to the power system analysis, an intelligent model can usefully bridge the time-domain information to the corresponding frequency-domain data. This paper proposes two neural network identifiers based on the existing time-domain average model of STATCOM. Extended resultant bridge presents an average-neural model of STATCOM, which can be analytically applied to power systems. To this extent, design and development of two neural network identifiers are performed using the dynamic neural network (DNN) and the multi-layer perceptron (MLP). To verify the developed models, the exact solutions obtained from the average model of STATCOM are compared with the outcomes of the DNN and the MLP identifiers. Moreover performance of the two identifiers is accordingly compared as well.
{"title":"Neural Identification of Average Model of STATCOM using DNN and MLP","authors":"M. T. Bina, S. Rahimzadeh","doi":"10.1109/PEDS.2007.4487932","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487932","url":null,"abstract":"Modeling of STATCOM is conventionally performed in the time-domain. Amongst them, dq-theory is well-known in which state-space equations are used for the analysis. Power systems, however, use the frequency-domain information in phasor-related studies such as load flow analysis. Because time-domain models of FACTS controllers cannot be directly applied to the power system analysis, an intelligent model can usefully bridge the time-domain information to the corresponding frequency-domain data. This paper proposes two neural network identifiers based on the existing time-domain average model of STATCOM. Extended resultant bridge presents an average-neural model of STATCOM, which can be analytically applied to power systems. To this extent, design and development of two neural network identifiers are performed using the dynamic neural network (DNN) and the multi-layer perceptron (MLP). To verify the developed models, the exact solutions obtained from the average model of STATCOM are compared with the outcomes of the DNN and the MLP identifiers. Moreover performance of the two identifiers is accordingly compared as well.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134360359","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487905
S.W. Lee, H. Dehbonei, S. Ko, S.R. Lee, B. Jang, Y. Moon, T. Ko
This paper presents an improved parallel processing uninterruptible power supply (UPS) for a strong grid using a bi-directional voltage-controlled voltage source inverter (VCVSI). To maintain the load voltage at the desired value and to control the active power flow between the VCVSI and grid, the amplitude and phase angle of the inverter output voltage (power angle) must be controlled. Selecting the power angle operating range is an important factor which has a direct effect on various parameters, such as the size of a decoupling inductor, grid power factor and the power ratings of VCVSI components. It is shown how the optimum power angles can be chosen and by restricting the operation of this, the power factor can be maintained above 0.9 at different loads and operating conditions. The paper examines the steady state modeling and analysis of a single phase parallel processing UPS while maintaining a high system power factor under different conditions. Experimental and simulation results of a prototyped 1 KVA VCVSI confirms the validity of the proposed method.
提出了一种基于双向压控电压源逆变器(VCVSI)的强电网并联处理不间断电源(UPS)。为了使负载电压保持在理想值，并控制VCVSI与电网之间的有功潮流，必须控制逆变器输出电压的幅值和相位角(功率角)。功率角工作范围的选择是一个重要的因素，它直接影响到去耦电感的尺寸、电网功率因数和VCVSI元件的额定功率等参数。演示了如何选择最佳功率角，并通过限制其运行，可以在不同负载和运行条件下将功率因数保持在0.9以上。本文研究了在不同条件下保持高系统功率因数的单相并联处理UPS的稳态建模和分析。1 KVA VCVSI样机的实验和仿真结果验证了该方法的有效性。
{"title":"An Improved Parallel Processing UPS Using a Voltage-Controlled Voltage Source Inverter","authors":"S.W. Lee, H. Dehbonei, S. Ko, S.R. Lee, B. Jang, Y. Moon, T. Ko","doi":"10.1109/PEDS.2007.4487905","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487905","url":null,"abstract":"This paper presents an improved parallel processing uninterruptible power supply (UPS) for a strong grid using a bi-directional voltage-controlled voltage source inverter (VCVSI). To maintain the load voltage at the desired value and to control the active power flow between the VCVSI and grid, the amplitude and phase angle of the inverter output voltage (power angle) must be controlled. Selecting the power angle operating range is an important factor which has a direct effect on various parameters, such as the size of a decoupling inductor, grid power factor and the power ratings of VCVSI components. It is shown how the optimum power angles can be chosen and by restricting the operation of this, the power factor can be maintained above 0.9 at different loads and operating conditions. The paper examines the steady state modeling and analysis of a single phase parallel processing UPS while maintaining a high system power factor under different conditions. Experimental and simulation results of a prototyped 1 KVA VCVSI confirms the validity of the proposed method.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134466969","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487836
Sufen Chen, Y. Lai, Siew-Chong Tan, C. Tse
This paper proposes a hybrid sliding mode repetitive control scheme that combines both the features of the sliding mode control and the repetitive control to achieve excellent transient and steady-state system performances in voltage source inverters. The principle of equivalent control is adopted to integrate the two methodologies and to facilitate the design and analysis of the proposed scheme. A specific low pass filter is also introduced to improve the transient response of the regulation. Experimental results show that fast dynamical responses are achieved through the sliding mode control, while low harmonic distortions are achieved through the repetitive control.
{"title":"Sliding Mode Repetitive Control of PWM Voltage Source Inverter","authors":"Sufen Chen, Y. Lai, Siew-Chong Tan, C. Tse","doi":"10.1109/PEDS.2007.4487836","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487836","url":null,"abstract":"This paper proposes a hybrid sliding mode repetitive control scheme that combines both the features of the sliding mode control and the repetitive control to achieve excellent transient and steady-state system performances in voltage source inverters. The principle of equivalent control is adopted to integrate the two methodologies and to facilitate the design and analysis of the proposed scheme. A specific low pass filter is also introduced to improve the transient response of the regulation. Experimental results show that fast dynamical responses are achieved through the sliding mode control, while low harmonic distortions are achieved through the repetitive control.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114097030","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487726
Hung-Chih Lin, Tsin-Yuan Chang
This paper presents the analysis and design of a sliding mode controller for buck converters operating in discontinuous conduction mode. An adaptive hysteresis band control scheme is proposed to tightly regulate the output voltage under line and load variations. The proposed method can be employed for other dc-dc converters, and therefore the operation range of sliding mode controllers for dc-dc converters can be extended from continuous conduction mode to discontinuous conduction mode. Simulation results are provided to verify the proposed technique.
{"title":"Analysis and Design of a Sliding Mode Controller for Buck Converters Operating in DCM with Adaptive Hysteresis Band Control Scheme","authors":"Hung-Chih Lin, Tsin-Yuan Chang","doi":"10.1109/PEDS.2007.4487726","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487726","url":null,"abstract":"This paper presents the analysis and design of a sliding mode controller for buck converters operating in discontinuous conduction mode. An adaptive hysteresis band control scheme is proposed to tightly regulate the output voltage under line and load variations. The proposed method can be employed for other dc-dc converters, and therefore the operation range of sliding mode controllers for dc-dc converters can be extended from continuous conduction mode to discontinuous conduction mode. Simulation results are provided to verify the proposed technique.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115129431","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487825
D. Schroder, H. Schuster, C. Westermaier
This paper investigates two different strategies to control nonlinear mechatronic systems. The first method is applicable for a plant with known linear part and unknown static nonlinearity. By an intelligent observer the nonlinear characteristic is identified, such that the result of the identification can be used to improve the performance of the controller. The second approach presented is non-identifier-based. Hence, no identification is necessary if the system possesses some structural attributes. A time-varying control law is employed, which reacts on the present behaviour of the error signal instantaneously. The appealing feature is that bounds for the control error can be fixed a priori.
{"title":"Mechatronic - Advanced Computational Intelligence","authors":"D. Schroder, H. Schuster, C. Westermaier","doi":"10.1109/PEDS.2007.4487825","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487825","url":null,"abstract":"This paper investigates two different strategies to control nonlinear mechatronic systems. The first method is applicable for a plant with known linear part and unknown static nonlinearity. By an intelligent observer the nonlinear characteristic is identified, such that the result of the identification can be used to improve the performance of the controller. The second approach presented is non-identifier-based. Hence, no identification is necessary if the system possesses some structural attributes. A time-varying control law is employed, which reacts on the present behaviour of the error signal instantaneously. The appealing feature is that bounds for the control error can be fixed a priori.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"524 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124491559","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487870
J. Nishimura, K. Oka, K. Matsuse
A purpose of this paper is to present the speed- sensorless vector method of parallel-connected dual induction motors fed by one inverter. This system may be unstable when the ratings of each induction motor are different and an extremely unbalanced load for both motors is added. Then we suggest a control method that the system can be stable in this condition. According to this method, the rotor flux is directly controlled to be constant by a rotor flux feedback control though it isn't controlled in an ordinary system.
{"title":"A Method of Speed Sensorless Vector Control Parallel -Connected Dual Induction Motors Fed by One Inverter in a Rotor Flux Feedback Control","authors":"J. Nishimura, K. Oka, K. Matsuse","doi":"10.1109/PEDS.2007.4487870","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487870","url":null,"abstract":"A purpose of this paper is to present the speed- sensorless vector method of parallel-connected dual induction motors fed by one inverter. This system may be unstable when the ratings of each induction motor are different and an extremely unbalanced load for both motors is added. Then we suggest a control method that the system can be stable in this condition. According to this method, the rotor flux is directly controlled to be constant by a rotor flux feedback control though it isn't controlled in an ordinary system.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122985868","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487759
A. Singer, W. Hofmann
Permanent magnet salient pole synchronous connected dc network produces less power than the rated power even at rated excitation. Static synchronous series compensation (SSSC) provides a solution to this problem. Since SSSC compensates the reactance voltages drop of the generator. The passive filters are used to eliminate the harmonics which are generated by nonlinear loads. This paper presents simulation and experimental results when applying static synchronous series compensation and passive filter to permanent magnet salient pole synchronous generator (PSG) in order to increase the output power, stabilize the output voltage and get rid of the harmonic respectively.
{"title":"Combined System of Static Synchronous Series Compensation and Passive Filter applied to Wind Energy Conversion System","authors":"A. Singer, W. Hofmann","doi":"10.1109/PEDS.2007.4487759","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487759","url":null,"abstract":"Permanent magnet salient pole synchronous connected dc network produces less power than the rated power even at rated excitation. Static synchronous series compensation (SSSC) provides a solution to this problem. Since SSSC compensates the reactance voltages drop of the generator. The passive filters are used to eliminate the harmonics which are generated by nonlinear loads. This paper presents simulation and experimental results when applying static synchronous series compensation and passive filter to permanent magnet salient pole synchronous generator (PSG) in order to increase the output power, stabilize the output voltage and get rid of the harmonic respectively.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"127 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113953532","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 : 2007-11-01DOI: 10.1109/PEDS.2007.4487941
W. Pusorn, W. Srisongkram, W. Subsingha, S. Deng-em, P. Boonchiam
This paper presents a solid state circuit breaker (SSCB) for a low distribution level. When voltage disturbances occurred, the SSCB operates for keeping the system limitations. Power semiconductor devices are compared and selected by using the performances of their devices. SSCB is provided with circuitry for permitting off/on/reset operations actuated by a mechanical toggle control switch for close simulation of magnetic circuit breaker operation. A power continuity feature is provided for load power by locating the control switch so that it opens all of the circuit, except the static power switch branch, between the source and the load, to provide a high degree of fail-safe protection for the apparatus. The synchronous reference frame is used to detect the current disturbances and control the switches. Simulation results are shown that SSCB offers advantages when compared to present solutions. A switching circuit that is particularly applicable to high voltage 3 phases solid state circuit breakers (SSCB). The circuit comprises a solid state switch; an energy absorbing device connected in parallel with said switch to form a parallel combination; an inductor connected in series with said parallel combination; and a control circuit connected to said solid state switch and adapted to turn off said switch in response to a predetermined voltage/current condition.
{"title":"Low Cost AC Solid State Circuit Breaker","authors":"W. Pusorn, W. Srisongkram, W. Subsingha, S. Deng-em, P. Boonchiam","doi":"10.1109/PEDS.2007.4487941","DOIUrl":"https://doi.org/10.1109/PEDS.2007.4487941","url":null,"abstract":"This paper presents a solid state circuit breaker (SSCB) for a low distribution level. When voltage disturbances occurred, the SSCB operates for keeping the system limitations. Power semiconductor devices are compared and selected by using the performances of their devices. SSCB is provided with circuitry for permitting off/on/reset operations actuated by a mechanical toggle control switch for close simulation of magnetic circuit breaker operation. A power continuity feature is provided for load power by locating the control switch so that it opens all of the circuit, except the static power switch branch, between the source and the load, to provide a high degree of fail-safe protection for the apparatus. The synchronous reference frame is used to detect the current disturbances and control the switches. Simulation results are shown that SSCB offers advantages when compared to present solutions. A switching circuit that is particularly applicable to high voltage 3 phases solid state circuit breakers (SSCB). The circuit comprises a solid state switch; an energy absorbing device connected in parallel with said switch to form a parallel combination; an inductor connected in series with said parallel combination; and a control circuit connected to said solid state switch and adapted to turn off said switch in response to a predetermined voltage/current condition.","PeriodicalId":166704,"journal":{"name":"2007 7th International Conference on Power Electronics and Drive Systems","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122715332","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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