Pub Date : 2014-12-01DOI: 10.1109/IICPE.2014.7115839
V. Chugh, J. Ohri
In this paper linear quadratic Regulator (LQR) and Proportional integral derivative (PID) controllers are designed for pitch control system of an aircraft. Genetic Algorithm (GA) is used for tuning the parameter LQR and PID controllers. The controller design begins with the appropriate mathematical model to account the longitudinal motion of an aircraft. Simulation is done within the MATLAB and results for the pitch angle response of an aircraft are represented in step's response. LQR and PID controllers are associated with their parameters which can either be tuned manually or by optimized methods like genetic algorithms to get better control and enhancement in the performance. GA is the powerful tool in the field of global optimization to various problems. Here genetic algorithm is successfully applied for Pitch control of an aircraft using MATLAB simulation for tuning of LQR and PID controllers and thus optimized parameters values for the LQR and PID controllers are derived.
{"title":"GA tuned LQR and PID controller for aircraft pitch control","authors":"V. Chugh, J. Ohri","doi":"10.1109/IICPE.2014.7115839","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115839","url":null,"abstract":"In this paper linear quadratic Regulator (LQR) and Proportional integral derivative (PID) controllers are designed for pitch control system of an aircraft. Genetic Algorithm (GA) is used for tuning the parameter LQR and PID controllers. The controller design begins with the appropriate mathematical model to account the longitudinal motion of an aircraft. Simulation is done within the MATLAB and results for the pitch angle response of an aircraft are represented in step's response. LQR and PID controllers are associated with their parameters which can either be tuned manually or by optimized methods like genetic algorithms to get better control and enhancement in the performance. GA is the powerful tool in the field of global optimization to various problems. Here genetic algorithm is successfully applied for Pitch control of an aircraft using MATLAB simulation for tuning of LQR and PID controllers and thus optimized parameters values for the LQR and PID controllers are derived.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127561554","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115796
I. Jha, S. Sen, M. Tiwari, M. Singh
Increasing penetration levels of Renewable Energy Sources (RES) into the grid has raised several concerns due to the intermittency, variability and uncertainty in power outputs. Technological advancements are required to tackle the issues of reliability, stability and power quality. Battery Energy Storage Systems (BESS) are widely being tested and have been found useful to address these challenges. This paper discusses the Frequency Regulation (FR) application of BESS. Several control strategies suggested in literature have been simulated for the frequency variations in the Indian scenario and the constraints limiting the utilization have been identified. A new control strategy has been proposed to enhance the usability of BESS for FR in Indian grid. Simulations have been carried out on MATLAB/Simulink platform and the results validate the advantages of the new control strategy over the existing ones.
{"title":"Control strategy for Frequency Regulation using Battery Energy Storage with optimal utilization","authors":"I. Jha, S. Sen, M. Tiwari, M. Singh","doi":"10.1109/IICPE.2014.7115796","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115796","url":null,"abstract":"Increasing penetration levels of Renewable Energy Sources (RES) into the grid has raised several concerns due to the intermittency, variability and uncertainty in power outputs. Technological advancements are required to tackle the issues of reliability, stability and power quality. Battery Energy Storage Systems (BESS) are widely being tested and have been found useful to address these challenges. This paper discusses the Frequency Regulation (FR) application of BESS. Several control strategies suggested in literature have been simulated for the frequency variations in the Indian scenario and the constraints limiting the utilization have been identified. A new control strategy has been proposed to enhance the usability of BESS for FR in Indian grid. Simulations have been carried out on MATLAB/Simulink platform and the results validate the advantages of the new control strategy over the existing ones.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123063863","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115746
Abhinav Jain, A. Gupta, Ashwani Kumar
This paper presents an effective method for the identification of candidate bus for DSTATCOM placement for the minimization of power losses and improvement of voltage profile in radial distribution system with load modeling. The D-STATCOM is modeled for determination of its size by assuming the voltage magnitude as 1 p.u. at the candidate bus. The validity of the method is tested on the standard IEEE 33-bus radial distribution system by performing load flow analysis after compensating the candidate bus using MATLAB software. The results obtained are compared without and with the D-STATCOM for all load models. The voltage profile and the losses reduction is obtained for IEEE 33 bus test system with the optimal placement of D-STATCOM based on the sensitivity index.
{"title":"An efficient method for D-STATCOM placement in radial distribution system","authors":"Abhinav Jain, A. Gupta, Ashwani Kumar","doi":"10.1109/IICPE.2014.7115746","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115746","url":null,"abstract":"This paper presents an effective method for the identification of candidate bus for DSTATCOM placement for the minimization of power losses and improvement of voltage profile in radial distribution system with load modeling. The D-STATCOM is modeled for determination of its size by assuming the voltage magnitude as 1 p.u. at the candidate bus. The validity of the method is tested on the standard IEEE 33-bus radial distribution system by performing load flow analysis after compensating the candidate bus using MATLAB software. The results obtained are compared without and with the D-STATCOM for all load models. The voltage profile and the losses reduction is obtained for IEEE 33 bus test system with the optimal placement of D-STATCOM based on the sensitivity index.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127711162","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115789
Jincy Philip, Bhim Singh, S. Mishra
This paper evaluates an isolated system using a character of triangle function (CTF) based control methodology for control and improved power quality. The hybrid-isolated system consists of a solar photovoltaic (SPV) array, diesel driven permanent magnet synchronous generator (PMSG) and a battery energy storage system (BESS). The configuration of the controller is simple and it is employed for the estimation of the source reference currents. The essential objective of a four-leg voltage source converter (VSC) is to provide voltage control, load balancing, neutral current compensation and harmonics elimination while feeding three phase four wire loads. The performance of the system with proposed control strategy has been estimated by modelling the system in Matlab with Simulink and SPS (Sim-Power System) toolboxes and authenticated through simulation results.
{"title":"Analysis and control of an isolated SPV-DG-BESS hybrid system","authors":"Jincy Philip, Bhim Singh, S. Mishra","doi":"10.1109/IICPE.2014.7115789","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115789","url":null,"abstract":"This paper evaluates an isolated system using a character of triangle function (CTF) based control methodology for control and improved power quality. The hybrid-isolated system consists of a solar photovoltaic (SPV) array, diesel driven permanent magnet synchronous generator (PMSG) and a battery energy storage system (BESS). The configuration of the controller is simple and it is employed for the estimation of the source reference currents. The essential objective of a four-leg voltage source converter (VSC) is to provide voltage control, load balancing, neutral current compensation and harmonics elimination while feeding three phase four wire loads. The performance of the system with proposed control strategy has been estimated by modelling the system in Matlab with Simulink and SPS (Sim-Power System) toolboxes and authenticated through simulation results.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131265087","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115838
M. Garg, Y. V. Hote
In this paper, mathematical modeling of dc-dc buck and boost converter is presented using Leverrier algorithm. The main advantage of this method is that there is no need to determine the inverse of a matrix and hence, this method is computationally efficient. Further, it shown that by reducing second order model of dc-dc buck and boost converter to first order, similar performance can be achieved. The simulation results and performance evaluation are carried out using MATLAB, which depicts that original system responses match well with responses of reduced order models.
{"title":"Leverrier algorithm based reduced order modeling of dc-dc converters","authors":"M. Garg, Y. V. Hote","doi":"10.1109/IICPE.2014.7115838","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115838","url":null,"abstract":"In this paper, mathematical modeling of dc-dc buck and boost converter is presented using Leverrier algorithm. The main advantage of this method is that there is no need to determine the inverse of a matrix and hence, this method is computationally efficient. Further, it shown that by reducing second order model of dc-dc buck and boost converter to first order, similar performance can be achieved. The simulation results and performance evaluation are carried out using MATLAB, which depicts that original system responses match well with responses of reduced order models.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130222354","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115792
Malik Sameeullah, A. Swarup
This paper proposes the mathematical modeling of Photovoltaic (PV) module using single diode model and use it to study the performance of PV array under partial shading condition. Partial shading is one of the major causes of reducing energy output in solar PV array. Due to partial shading, PV characteristics get more complex. In order to extract maximum power under shading condition, its performance has to be studies. In this paper, Matlab based mathematical model is used to study the performance of Perturbation & Observation (PO) based Maximum Power Point Tracker (MPPT) controller under partial shading condition. Further, ecosense Insight Solar PV Training kit is used to justify the mathematical model.
{"title":"Modeling of PV module to study the performance of MPPT controller under partial shading condition","authors":"Malik Sameeullah, A. Swarup","doi":"10.1109/IICPE.2014.7115792","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115792","url":null,"abstract":"This paper proposes the mathematical modeling of Photovoltaic (PV) module using single diode model and use it to study the performance of PV array under partial shading condition. Partial shading is one of the major causes of reducing energy output in solar PV array. Due to partial shading, PV characteristics get more complex. In order to extract maximum power under shading condition, its performance has to be studies. In this paper, Matlab based mathematical model is used to study the performance of Perturbation & Observation (PO) based Maximum Power Point Tracker (MPPT) controller under partial shading condition. Further, ecosense Insight Solar PV Training kit is used to justify the mathematical model.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121072568","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7145017
Sanjiv Kumar, P. Agarwal
A novel hybrid eighteen-level inverter topology for open-end winding induction motor (IM) is presented in this paper. In the proposed topology one end of the open-end IM is fed by conventional two-level inverter, while other end is connected to a nine-level cascade H-bridge (CHB) inverter. The combined effect of these two inverters generates eighteen-level in the phase voltage of open-end winding IM. The two-level inverter with higher DC link voltage has lower switching frequency and thereby reduces the switching losses. In addition to that, the proposed topology requires less number of components as compared to conventional multilevel inverter (MLI) topology. An interesting feature of the proposed topology is that, it can operate in nine-level mode by connecting the motor winding in star in case of failure of two-level inverter. Similarly if the fault occurs in CHB inverter the proposed inverter can operate in two-level mode. Thus the reliability of the system is improved. Exhaustive simulation study is carried out to evaluate the performance of proposed inverter for the entire modulation range and results are presented.
{"title":"A novel eighteen-level inverter for an open-end winding induction motor","authors":"Sanjiv Kumar, P. Agarwal","doi":"10.1109/IICPE.2014.7145017","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7145017","url":null,"abstract":"A novel hybrid eighteen-level inverter topology for open-end winding induction motor (IM) is presented in this paper. In the proposed topology one end of the open-end IM is fed by conventional two-level inverter, while other end is connected to a nine-level cascade H-bridge (CHB) inverter. The combined effect of these two inverters generates eighteen-level in the phase voltage of open-end winding IM. The two-level inverter with higher DC link voltage has lower switching frequency and thereby reduces the switching losses. In addition to that, the proposed topology requires less number of components as compared to conventional multilevel inverter (MLI) topology. An interesting feature of the proposed topology is that, it can operate in nine-level mode by connecting the motor winding in star in case of failure of two-level inverter. Similarly if the fault occurs in CHB inverter the proposed inverter can operate in two-level mode. Thus the reliability of the system is improved. Exhaustive simulation study is carried out to evaluate the performance of proposed inverter for the entire modulation range and results are presented.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117043084","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115772
T. Halder
The paper appropriately presents to popularize a sizeable copy of green power from the solar energy carried out by the flyback converters. The copy and paste of the free energy is married by a straight forward elemental optimization technique at which the conventional energy is shut down during the on grid to save power. The renewable energy is exclusively copied in backup systems and pasted for the off grid utilization or hurling over surplus power at the nearby grids to crack the monopole business of the power utilities. Last but not least, substantial solar power agriculture is accomplished by copy and paste modes of the smart operations.
{"title":"A practice of power paste with the isolated flyback converters","authors":"T. Halder","doi":"10.1109/IICPE.2014.7115772","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115772","url":null,"abstract":"The paper appropriately presents to popularize a sizeable copy of green power from the solar energy carried out by the flyback converters. The copy and paste of the free energy is married by a straight forward elemental optimization technique at which the conventional energy is shut down during the on grid to save power. The renewable energy is exclusively copied in backup systems and pasted for the off grid utilization or hurling over surplus power at the nearby grids to crack the monopole business of the power utilities. Last but not least, substantial solar power agriculture is accomplished by copy and paste modes of the smart operations.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115554477","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115804
M. Bhunia, Rajesh Gupta, B. Subudhi
To extract maximum available power from the PV system many maximum power point tracking (MPPT) algorithms with DC-DC converter have been proposed in the literature. However, due to change in load or environmental conditions, the output voltage from the DC-DC converter varies. The variable output voltages are not suitable for many applications requiring constant voltage. To overcome this difficultly, a cascaded DC-DC converter with battery storage system for standalone application is proposed in this paper. The proposed system comprises of a PV system connected with a boost DC-DC converter to deliver the available maximum power to the DC bus. A Single-ended primary inductor converter (SEPIC) is connected to the DC bus to provide regulated DC voltage to the load. A battery with charge controller is connected to the DC bus to improve the reliability of the system. The efficacy of the proposed topology is verified through the experimental studies pursued on a prototype PV connected converter system developed in the laboratory. Robustness studies with regard to variation in environmental parameters such as solar insolation and load variation were made. MPPT and voltage regulation algorithms were implemented in LABVIEW platform using data acquisition boards.
{"title":"Cascaded DC-DC converter for a reliable standalone PV fed DC load","authors":"M. Bhunia, Rajesh Gupta, B. Subudhi","doi":"10.1109/IICPE.2014.7115804","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115804","url":null,"abstract":"To extract maximum available power from the PV system many maximum power point tracking (MPPT) algorithms with DC-DC converter have been proposed in the literature. However, due to change in load or environmental conditions, the output voltage from the DC-DC converter varies. The variable output voltages are not suitable for many applications requiring constant voltage. To overcome this difficultly, a cascaded DC-DC converter with battery storage system for standalone application is proposed in this paper. The proposed system comprises of a PV system connected with a boost DC-DC converter to deliver the available maximum power to the DC bus. A Single-ended primary inductor converter (SEPIC) is connected to the DC bus to provide regulated DC voltage to the load. A battery with charge controller is connected to the DC bus to improve the reliability of the system. The efficacy of the proposed topology is verified through the experimental studies pursued on a prototype PV connected converter system developed in the laboratory. Robustness studies with regard to variation in environmental parameters such as solar insolation and load variation were made. MPPT and voltage regulation algorithms were implemented in LABVIEW platform using data acquisition boards.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127207918","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115795
S. Lakshmanan, Amit Jain, B. Rajpurohit
Power produced from the Renewable Energy Sources (RES) is directly feeding to the electric grid via Power Electronic Circuits (PEC). Grid connected solar Photovoltaic (PV) system requires a high quality of grid monitoring techniques in order to detect the phase angle, voltage magnitude and frequency and also to meet standard specifications in terms of achieving power quality and safety. Various techniques are used to detect phase angle, amplitude and frequency of the grid connected solar PV system. This paper proposes a review of important voltage monitoring techniques for single phase grid connected solar PV system and it also proposes a design of Adaptive Notch Phase Lock Loop (ANPLL) circuit for single phase grid connected solar PV system under both ideal and non-ideal grid conditions. Here the Loop Filter (LF) of the PLL circuit is a Proportional Integral Derivative (PID) type and the proposed PLL circuit is implemented using Matlab/Simulink platform and simulation results are obtained for both ideal and non-ideal grid conditions.
{"title":"Grid voltage monitoring techniques for single phase grid connected solar PV system","authors":"S. Lakshmanan, Amit Jain, B. Rajpurohit","doi":"10.1109/IICPE.2014.7115795","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115795","url":null,"abstract":"Power produced from the Renewable Energy Sources (RES) is directly feeding to the electric grid via Power Electronic Circuits (PEC). Grid connected solar Photovoltaic (PV) system requires a high quality of grid monitoring techniques in order to detect the phase angle, voltage magnitude and frequency and also to meet standard specifications in terms of achieving power quality and safety. Various techniques are used to detect phase angle, amplitude and frequency of the grid connected solar PV system. This paper proposes a review of important voltage monitoring techniques for single phase grid connected solar PV system and it also proposes a design of Adaptive Notch Phase Lock Loop (ANPLL) circuit for single phase grid connected solar PV system under both ideal and non-ideal grid conditions. Here the Loop Filter (LF) of the PLL circuit is a Proportional Integral Derivative (PID) type and the proposed PLL circuit is implemented using Matlab/Simulink platform and simulation results are obtained for both ideal and non-ideal grid conditions.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125403344","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：