Pub Date : 2016-11-01DOI: 10.1109/POWERI.2016.8077467
U. Kalla
This paper is aimed at normalized neural network based control scheme for power quality improved integration of solar PV and utility grid. In the proposed scheme the solar PV and grid are integrated using a three leg voltage source converter consists of six IGBTs, three interfacing inductors and a DC bus capacitor. The neural network based scheme is used for estimating fundamental real and reactive power components of the load current in all three phases independently therefore the three phase grid current remains balanced and sinusoidal under all type of loading conditions including unbalancing in load currents of three phases. The proposed controller mitigates the harmonic current, compensates reactive power need of the system, improves system power factor and regulates the system voltage at the point of common coupling (PCC).
{"title":"A normalized neural network based controller for power quality improved grid connected solar PV systems","authors":"U. Kalla","doi":"10.1109/POWERI.2016.8077467","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077467","url":null,"abstract":"This paper is aimed at normalized neural network based control scheme for power quality improved integration of solar PV and utility grid. In the proposed scheme the solar PV and grid are integrated using a three leg voltage source converter consists of six IGBTs, three interfacing inductors and a DC bus capacitor. The neural network based scheme is used for estimating fundamental real and reactive power components of the load current in all three phases independently therefore the three phase grid current remains balanced and sinusoidal under all type of loading conditions including unbalancing in load currents of three phases. The proposed controller mitigates the harmonic current, compensates reactive power need of the system, improves system power factor and regulates the system voltage at the point of common coupling (PCC).","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"182 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125585304","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077443
Tirthasarathi Lodh, Akshay Subramaniam, A. K. Paswan
This paper proposes two assistive mobility devices for individuals with visual impairments. These devices use ultrasound technology for the detection of the obstacle distance and a vibration motor - based tactile interface system that generates different vibration patterns as a function of obstacle distance to alert the user. The main device consists of an ultrasound sensor and associated control board mounted on goggles along with a tactile interface mounted on an armband. The auxiliary device consists of an ultrasound sensor mounted on a conventional cane which detects below-knee obstacles. The electronic circuitry present in the two devices has been explained in detail. Working prototypes of both these parts of the device have been developed and tested for desired results.
{"title":"Ultrasound based assistive mobility devices for the visually-impaired","authors":"Tirthasarathi Lodh, Akshay Subramaniam, A. K. Paswan","doi":"10.1109/POWERI.2016.8077443","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077443","url":null,"abstract":"This paper proposes two assistive mobility devices for individuals with visual impairments. These devices use ultrasound technology for the detection of the obstacle distance and a vibration motor - based tactile interface system that generates different vibration patterns as a function of obstacle distance to alert the user. The main device consists of an ultrasound sensor and associated control board mounted on goggles along with a tactile interface mounted on an armband. The auxiliary device consists of an ultrasound sensor mounted on a conventional cane which detects below-knee obstacles. The electronic circuitry present in the two devices has been explained in detail. Working prototypes of both these parts of the device have been developed and tested for desired results.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134212649","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077416
S. Sridhar, K. Rao, K. Harish, R. Umesh
The Condition Monitoring of Induction Motor (IM) is performed to ensure optimal and reliable operation, as IM has numerous applications spread across varied sectors. Mechanical faults such as Broken Rotor bar fault of IM along with supply PQ disturbances create a high degree of non-linearity in the supply. This non-linearity is examined by stator current signature analysis which involves the computation of the Negative Sequence Components (NSC) and Total Harmonic Distortions (THD) of the stator current. These values are given as inputs to the Artificial Neural Network (ANN), Support Vector Machine (SVM) and k-Nearest Neighbor (kNN) classifiers. The results of the classifiers are obtained and compared. It is seen that the classification accuracy for ANN is found to be 90.63%, while for SVM is found to be 92.71% and that of kNN is found to be 85.41%.
{"title":"Condition monitoring of induction motor using negative sequence component and THD of the stator current","authors":"S. Sridhar, K. Rao, K. Harish, R. Umesh","doi":"10.1109/POWERI.2016.8077416","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077416","url":null,"abstract":"The Condition Monitoring of Induction Motor (IM) is performed to ensure optimal and reliable operation, as IM has numerous applications spread across varied sectors. Mechanical faults such as Broken Rotor bar fault of IM along with supply PQ disturbances create a high degree of non-linearity in the supply. This non-linearity is examined by stator current signature analysis which involves the computation of the Negative Sequence Components (NSC) and Total Harmonic Distortions (THD) of the stator current. These values are given as inputs to the Artificial Neural Network (ANN), Support Vector Machine (SVM) and k-Nearest Neighbor (kNN) classifiers. The results of the classifiers are obtained and compared. It is seen that the classification accuracy for ANN is found to be 90.63%, while for SVM is found to be 92.71% and that of kNN is found to be 85.41%.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132637199","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077290
T. H. Priya, A. M. Parimi
The increased concerns for environmental protection and energy conservation had led to accelerated growth in PV technologies, however large scale integration of this to an AC grid will have a serious impact on power system operation. Development of DC power system is chosen as a solution to overcome many of those impacts. Photovoltaic arrays used here will generate an output at a low voltage level, to integrate this to high voltage DC grid a high voltage gain multi level boost converter (MLBC) is chosen, which includes conventional boost converter circuit in addition to switched capacitor circuit. MLBC offers high gain factors without attaining extreme duty ratios, continuous input current, low stress voltage across the switch and reduced component ratings. Adaptive perturb and observe (P&O) fuzzy MPPT controller is chosen here to track the maximum power point (MPP) for fluctuating input irradiation. MLBC topology along with chosen MPPT controller will achieve dual functionality of high voltage gain and maximum power point tracking. The performance of chosen MPPT on MLBC is compared with other MPPT techniques. The results of Matlab simulation were illustrated for corroborating its performance.
{"title":"Design of adaptive perturb and observe-fuzzy MPPT controller for high voltage gain multilevel boost converter","authors":"T. H. Priya, A. M. Parimi","doi":"10.1109/POWERI.2016.8077290","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077290","url":null,"abstract":"The increased concerns for environmental protection and energy conservation had led to accelerated growth in PV technologies, however large scale integration of this to an AC grid will have a serious impact on power system operation. Development of DC power system is chosen as a solution to overcome many of those impacts. Photovoltaic arrays used here will generate an output at a low voltage level, to integrate this to high voltage DC grid a high voltage gain multi level boost converter (MLBC) is chosen, which includes conventional boost converter circuit in addition to switched capacitor circuit. MLBC offers high gain factors without attaining extreme duty ratios, continuous input current, low stress voltage across the switch and reduced component ratings. Adaptive perturb and observe (P&O) fuzzy MPPT controller is chosen here to track the maximum power point (MPP) for fluctuating input irradiation. MLBC topology along with chosen MPPT controller will achieve dual functionality of high voltage gain and maximum power point tracking. The performance of chosen MPPT on MLBC is compared with other MPPT techniques. The results of Matlab simulation were illustrated for corroborating its performance.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131218116","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077152
V. K. Agrawal, Archit Khemka, Krishna Manoharan, Dheeraj Jain, S. Mukhopadhyay
India has ambitious plans to add unprecedented level of Renewable Energy on its power grid. The main driver towards this initiative is to achieve energy security by exploiting ways and means which are sustainable in nature and produce clean energy. This paper presents the philosophy towards commissioning of the country's first MW level grid-connected wind-solar hybrid project by M/s ReGen Powertech Pvt. Ltd. Under this project, Solar Photo-Voltaic (SPV) system has been additionally commissioned in a wind-farm premises, where a Wind Energy Convertor (WEC) is already operational. The combination facilitates substantial saving on number of counts, which include sharing of common land as well as some of the equipment, like inverter, transmission network for the evacuation of power, and common auxiliaries. Furthermore, by combining wind and solar, which are largely complimentary in nature, the overall variability of the output produced has also been moderated and the combined output is certainly more conducive towards integration with the grid. This paper presents the overall philosophy behind the subject topic and the way forward towards enhancing the capacities of such installations in the country.
{"title":"Wind-solar hybrid system — an innovative and smart approach to augment renewable generation and moderate variability to the grid","authors":"V. K. Agrawal, Archit Khemka, Krishna Manoharan, Dheeraj Jain, S. Mukhopadhyay","doi":"10.1109/POWERI.2016.8077152","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077152","url":null,"abstract":"India has ambitious plans to add unprecedented level of Renewable Energy on its power grid. The main driver towards this initiative is to achieve energy security by exploiting ways and means which are sustainable in nature and produce clean energy. This paper presents the philosophy towards commissioning of the country's first MW level grid-connected wind-solar hybrid project by M/s ReGen Powertech Pvt. Ltd. Under this project, Solar Photo-Voltaic (SPV) system has been additionally commissioned in a wind-farm premises, where a Wind Energy Convertor (WEC) is already operational. The combination facilitates substantial saving on number of counts, which include sharing of common land as well as some of the equipment, like inverter, transmission network for the evacuation of power, and common auxiliaries. Furthermore, by combining wind and solar, which are largely complimentary in nature, the overall variability of the output produced has also been moderated and the combined output is certainly more conducive towards integration with the grid. This paper presents the overall philosophy behind the subject topic and the way forward towards enhancing the capacities of such installations in the country.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130933127","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077382
Monika Manglani, S. Ola, M. Sharma, Bhavesh Vyas
Power system extends from generation to large distance load end, losses will be there in transmission & distribution section. This paper discusses the effect of capacitor placement, optimum voltage setting of generators, optimum dispatch of active power and SVC placement on power system losses and other technical parameters. IEEE 14 Bus system has been designed as test model in Mipower software. Separate case studies with individual and integrated applications are applied one after the other. Results have been organized for different case considerations. It is obtained that losses can be significantly reduced with optimum application and utilization of available loss reduction methods. The effect on network voltage profile, line loadings and bus angles has been compared with the base case. At the end integrated approach has been designed which is a combined model of applied loss reduction techniques on Test model. Comparison has also been obtained for 10 percent increased load of base condition.
{"title":"Integrated approach for loss reduction in power system","authors":"Monika Manglani, S. Ola, M. Sharma, Bhavesh Vyas","doi":"10.1109/POWERI.2016.8077382","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077382","url":null,"abstract":"Power system extends from generation to large distance load end, losses will be there in transmission & distribution section. This paper discusses the effect of capacitor placement, optimum voltage setting of generators, optimum dispatch of active power and SVC placement on power system losses and other technical parameters. IEEE 14 Bus system has been designed as test model in Mipower software. Separate case studies with individual and integrated applications are applied one after the other. Results have been organized for different case considerations. It is obtained that losses can be significantly reduced with optimum application and utilization of available loss reduction methods. The effect on network voltage profile, line loadings and bus angles has been compared with the base case. At the end integrated approach has been designed which is a combined model of applied loss reduction techniques on Test model. Comparison has also been obtained for 10 percent increased load of base condition.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131257204","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077379
Meenakshi Rastogi, A. H. Bhat, A. Zargar
One of the major issues in the present electrical power system is power quality. The power quality problems may be of many types whether at source side or load side. Distributed Static Synchronous Compensator (D-STATCOM) is the most convenient device among all FACTS devices for all these power quality problems. This paper deals with performance evaluation with and without D-STATCOM for voltage swell and sag at source side in one model and different types of faults conditions like LG, LLG, LLLG in other model. With the help of MATLAB/Simulink & SimPowerSystems software, the performance analysis of D-STATCOM has been done with conventional PI controller using Hysteresis Current Control (HCC) for the mitigation of these fault conditions.
{"title":"Performance evaluation of D-STATCOM for mitigation of power quality problems at different source and load side fault conditions","authors":"Meenakshi Rastogi, A. H. Bhat, A. Zargar","doi":"10.1109/POWERI.2016.8077379","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077379","url":null,"abstract":"One of the major issues in the present electrical power system is power quality. The power quality problems may be of many types whether at source side or load side. Distributed Static Synchronous Compensator (D-STATCOM) is the most convenient device among all FACTS devices for all these power quality problems. This paper deals with performance evaluation with and without D-STATCOM for voltage swell and sag at source side in one model and different types of faults conditions like LG, LLG, LLLG in other model. With the help of MATLAB/Simulink & SimPowerSystems software, the performance analysis of D-STATCOM has been done with conventional PI controller using Hysteresis Current Control (HCC) for the mitigation of these fault conditions.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"176 s416","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132905783","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077154
M. Kavitha, P. B. Bobba, D. Prasad
Magnetic resonance coupling (MRC) based wireless power transfer (WPT) system is recognized as an efficient and promising technology for safe, convenient and elegant charging solution for various electronic portable devices. MRC technology helps in transferring power wirelessly from transmitter to receiver over larger distances. However in such loosely coupled systems, low power transfer efficiency is the major issue in comparison to conventional wired charging systems. The paper presents detailed analysis of power transfer efficiency between two independent coils separated by distance of 15 cm. The analysis involves an effect of coil geometrical dimensions on power transfer efficiency and mutual inductance between transmitter (TX) and receiver coils (RX). In addition, the investigations are further extended to analyze the role of shielding and effect of shielding geometry on power transfer efficiency and mutual inductance between the two coils.
{"title":"Effect of coil geometry and shielding on wireless power transfer system","authors":"M. Kavitha, P. B. Bobba, D. Prasad","doi":"10.1109/POWERI.2016.8077154","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077154","url":null,"abstract":"Magnetic resonance coupling (MRC) based wireless power transfer (WPT) system is recognized as an efficient and promising technology for safe, convenient and elegant charging solution for various electronic portable devices. MRC technology helps in transferring power wirelessly from transmitter to receiver over larger distances. However in such loosely coupled systems, low power transfer efficiency is the major issue in comparison to conventional wired charging systems. The paper presents detailed analysis of power transfer efficiency between two independent coils separated by distance of 15 cm. The analysis involves an effect of coil geometrical dimensions on power transfer efficiency and mutual inductance between transmitter (TX) and receiver coils (RX). In addition, the investigations are further extended to analyze the role of shielding and effect of shielding geometry on power transfer efficiency and mutual inductance between the two coils.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132163470","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077183
Soumesh Chatterjee, B. K. Roy
Modern world smart grid is a combination of a reliable communication network, robust central generation and strategic commanded Distributed Generations (DG). Ungoverned penetration of DG to balance inflationist load will encourage grid instability. This paper proposes a modest methodology to analyse the transient stability of the electrical network with distributed generation and its effect on other important aspects like voltage stability, overall loss minimization, economic benefits, short circuit capacity, power quality and reliability of power system. The possible events have been simulated with 33 bus radial distributed system. The case studies have been extended to single and multi DG environment. ETAP 7.5 and MATLAB v10 have been used for simulation of case studies. Simulation results validate the promising outcome of this work.
{"title":"Transient stability and other important aspects of power system in Multi-DG environment","authors":"Soumesh Chatterjee, B. K. Roy","doi":"10.1109/POWERI.2016.8077183","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077183","url":null,"abstract":"Modern world smart grid is a combination of a reliable communication network, robust central generation and strategic commanded Distributed Generations (DG). Ungoverned penetration of DG to balance inflationist load will encourage grid instability. This paper proposes a modest methodology to analyse the transient stability of the electrical network with distributed generation and its effect on other important aspects like voltage stability, overall loss minimization, economic benefits, short circuit capacity, power quality and reliability of power system. The possible events have been simulated with 33 bus radial distributed system. The case studies have been extended to single and multi DG environment. ETAP 7.5 and MATLAB v10 have been used for simulation of case studies. Simulation results validate the promising outcome of this work.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132755659","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 : 2016-11-01DOI: 10.1109/POWERI.2016.8077457
D. Jain, U. Kalla
This paper presents the basics, design and analysis of LCL filters for connection with the grid. Different topologies of filter are discussed along with their drawbacks. Various passive damping techniques for LCL filter are presented and analyzed by plotting the frequency response curves. Large rating, bulky size of LC filter acts as a disadvantage and thus was tried to be compensated by LCL filter that provided more stability to the system as well as was cheaper as compared to latter.
{"title":"Design and analysis of LCL filter for interconnection with grid connected PV system","authors":"D. Jain, U. Kalla","doi":"10.1109/POWERI.2016.8077457","DOIUrl":"https://doi.org/10.1109/POWERI.2016.8077457","url":null,"abstract":"This paper presents the basics, design and analysis of LCL filters for connection with the grid. Different topologies of filter are discussed along with their drawbacks. Various passive damping techniques for LCL filter are presented and analyzed by plotting the frequency response curves. Large rating, bulky size of LC filter acts as a disadvantage and thus was tried to be compensated by LCL filter that provided more stability to the system as well as was cheaper as compared to latter.","PeriodicalId":332286,"journal":{"name":"2016 IEEE 7th Power India International Conference (PIICON)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115564279","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：