Pub Date : 2019-05-01DOI: 10.1109/PEPQA.2019.8851558
J. A. Ocampo-Wilches, D. Van Strahlen-Gutierrez, J. D. Lugo-Vergara, A. Ustariz-Farfán, E. Cano-Plata
This paper presents the results obtained of the simulation and implementation in hardware in the loop of fuses and overcurrent protections. First, the steps developed for construct the different blocks in MATLAB/SIMULINK considering the details for the curve approximation in the fuses are presented. Consequently, their implementation using the Dspace 1104 and TI 280F337S boards are presented, describing the characteristics of the signals measurement and the construction of the tripping module and interconnection of all the components of the test grid. Finally, the results obtained in simulation and those obtained whit the hardware in the loop system are compared.
{"title":"Methodology for Modeling and Implementation in Hardware-in-the-loop of Fuses and Overcurrent Protections","authors":"J. A. Ocampo-Wilches, D. Van Strahlen-Gutierrez, J. D. Lugo-Vergara, A. Ustariz-Farfán, E. Cano-Plata","doi":"10.1109/PEPQA.2019.8851558","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851558","url":null,"abstract":"This paper presents the results obtained of the simulation and implementation in hardware in the loop of fuses and overcurrent protections. First, the steps developed for construct the different blocks in MATLAB/SIMULINK considering the details for the curve approximation in the fuses are presented. Consequently, their implementation using the Dspace 1104 and TI 280F337S boards are presented, describing the characteristics of the signals measurement and the construction of the tripping module and interconnection of all the components of the test grid. Finally, the results obtained in simulation and those obtained whit the hardware in the loop system are compared.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"46 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134064174","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851573
Jhonathan Julián Gallego Rojas, D. Prada, William Alexander Londoño Marín Oswaldo Lopez-Santos
This paper presents a real-time emulation tool developed to integrate a small-scale wind turbine as distributed generator into a hybrid microgrid laboratory testbed. The wind dynamic is simulated by controlling an induction motor from a LabVIEW application to change the rotor speed of the turbine depending of a specified operation scenario defined by the user. Static behavior of the complete system was characterized by means of a black-box identification method using experimental data allowing also development of an accurate and simple model for simulation. Practical results show the high potentiality of the developed system in the study of microgrids.
{"title":"Real-Time Small-Scale Wind Turbine Emulator for a Hybrid Microgrid Laboratory Testbed","authors":"Jhonathan Julián Gallego Rojas, D. Prada, William Alexander Londoño Marín Oswaldo Lopez-Santos","doi":"10.1109/PEPQA.2019.8851573","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851573","url":null,"abstract":"This paper presents a real-time emulation tool developed to integrate a small-scale wind turbine as distributed generator into a hybrid microgrid laboratory testbed. The wind dynamic is simulated by controlling an induction motor from a LabVIEW application to change the rotor speed of the turbine depending of a specified operation scenario defined by the user. Static behavior of the complete system was characterized by means of a black-box identification method using experimental data allowing also development of an accurate and simple model for simulation. Practical results show the high potentiality of the developed system in the study of microgrids.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127551295","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851542
León Felipe Serna-Montoya, J. Cano-Quintero, N. Muñoz-Galeano, J. López-Lezama
Programmable electronic AC loads (PELs) are a new type of power electronic devices widely used by researches to emulate different load features, such as resistive, inductive, capacitive and non-linear loads. PELs are currently of great interest in the field of microgrid research, isolated or hybrid solar plants and power electronics device testing. This paper presents a review of PELs focusing on hardware topologies. Different hardware configurations are presented and discussed, explaining their functionality. One of the key issues regarding PELs design is the elimination of excessive active power drawn by the load. This can be performed by dissipating power in passive elements through DC-DC converters or re-injecting it into a receptive AC grid. Both options are explained and detailed in the paper.
{"title":"Programmable Electronic AC Loads: a Review on Hardware Topologies","authors":"León Felipe Serna-Montoya, J. Cano-Quintero, N. Muñoz-Galeano, J. López-Lezama","doi":"10.1109/PEPQA.2019.8851542","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851542","url":null,"abstract":"Programmable electronic AC loads (PELs) are a new type of power electronic devices widely used by researches to emulate different load features, such as resistive, inductive, capacitive and non-linear loads. PELs are currently of great interest in the field of microgrid research, isolated or hybrid solar plants and power electronics device testing. This paper presents a review of PELs focusing on hardware topologies. Different hardware configurations are presented and discussed, explaining their functionality. One of the key issues regarding PELs design is the elimination of excessive active power drawn by the load. This can be performed by dissipating power in passive elements through DC-DC converters or re-injecting it into a receptive AC grid. Both options are explained and detailed in the paper.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131056063","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851552
Rogger I. Rivera, E. Quispe, J. R. Gómez
In this paper the efficiency and segregated losses of an AC induction motor were determined considering method A of IEC 60034 2-3 standard. This work is based on the results of the 2-1-1b method, taken from [4], which shows the efficiency determination from two methods of the IEC 60034 2-1 standard. The standard IEC 60034 2-3 suggests a method to determine the content of harmonics provided by the speed driver to the converter-motor set. For this reason, the focus of this paper is aimed at extracting the component of harmonic losses generated by the switching of the semiconductor devices that make up the frequency converter and evaluate the effect on the performance of converter-motor set.
{"title":"Efficiency determination of converter-fed AC induction motors according to method A of IEC 60034 2-3 standard","authors":"Rogger I. Rivera, E. Quispe, J. R. Gómez","doi":"10.1109/PEPQA.2019.8851552","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851552","url":null,"abstract":"In this paper the efficiency and segregated losses of an AC induction motor were determined considering method A of IEC 60034 2-3 standard. This work is based on the results of the 2-1-1b method, taken from [4], which shows the efficiency determination from two methods of the IEC 60034 2-1 standard. The standard IEC 60034 2-3 suggests a method to determine the content of harmonics provided by the speed driver to the converter-motor set. For this reason, the focus of this paper is aimed at extracting the component of harmonic losses generated by the switching of the semiconductor devices that make up the frequency converter and evaluate the effect on the performance of converter-motor set.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114352601","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851568
Yulieth Jimenez, Jose D. Cortes, C. Duarte, J. Petit, G. Carrillo
Power quality information is useful not only to determine electricity fitness but also for another important application: load identification. One approach to identify loads is through non-intrusive load monitoring systems that estimate the nature and operation of individual appliances with measurements in a single point. In this work, load identification is addressed as a classification task by taking advantage of power quality information. Therefore, discriminant analysis of power quality characteristics are proposed, thus requiring simpler design and fitting processes than traditional techniques. In this regard, classifiers based on linear and quadratic discriminant analysis are implemented for laboratory measurements with noticeable performance.
{"title":"Non-intrusive discriminant analysis of loads based on power quality data","authors":"Yulieth Jimenez, Jose D. Cortes, C. Duarte, J. Petit, G. Carrillo","doi":"10.1109/PEPQA.2019.8851568","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851568","url":null,"abstract":"Power quality information is useful not only to determine electricity fitness but also for another important application: load identification. One approach to identify loads is through non-intrusive load monitoring systems that estimate the nature and operation of individual appliances with measurements in a single point. In this work, load identification is addressed as a classification task by taking advantage of power quality information. Therefore, discriminant analysis of power quality characteristics are proposed, thus requiring simpler design and fitting processes than traditional techniques. In this regard, classifiers based on linear and quadratic discriminant analysis are implemented for laboratory measurements with noticeable performance.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127538320","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851537
Luis Muñoz, M. Rios
Voltage source converters (VSC) based HVDC grids are a secure alternative for power transmission in the electric regional integration of many countries around the world, and the integration of renewable sources. The main objective of this paper is to compare the dynamic performance of three modes of control of VSC stations the voltage control methods “Control margin voltage” and “Droop control voltage” to show that the droop voltage control strategy has better results than the voltage margin control strategy. The performance of these controllers is evaluated by means of a perturbation on a VSC station that consists of outage of the negative pole over the bipolar converter station in the DC subsystem DSC3 of the CIGRE DC Grid benchmark test system. The dynamic simulation allows conclude that using a strategic voltage control like margin control voltage is possible have a better level of voltage and active power in the lines DC, the establishment time of the system is 6s. The droop control voltage with acceptable levels of voltage and active power can be faster, stabilizing the system at 1s.
{"title":"Performance Comparison of Voltage Control Strategies of VSC-HVDC Grids","authors":"Luis Muñoz, M. Rios","doi":"10.1109/PEPQA.2019.8851537","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851537","url":null,"abstract":"Voltage source converters (VSC) based HVDC grids are a secure alternative for power transmission in the electric regional integration of many countries around the world, and the integration of renewable sources. The main objective of this paper is to compare the dynamic performance of three modes of control of VSC stations the voltage control methods “Control margin voltage” and “Droop control voltage” to show that the droop voltage control strategy has better results than the voltage margin control strategy. The performance of these controllers is evaluated by means of a perturbation on a VSC station that consists of outage of the negative pole over the bipolar converter station in the DC subsystem DSC3 of the CIGRE DC Grid benchmark test system. The dynamic simulation allows conclude that using a strategic voltage control like margin control voltage is possible have a better level of voltage and active power in the lines DC, the establishment time of the system is 6s. The droop control voltage with acceptable levels of voltage and active power can be faster, stabilizing the system at 1s.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128076713","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851561
L. Castro, M. López, J. Mora-Flórez
This paper proposes the design of Fuzzy logic control applied to the outer loop of a voltage source converter, which is indispensable the integration of renewable sources and storage devices in a micro grid. The fuzzy logic method is implemented in non-linear, uncertain or non-stationary processes, since it is characterized by its ease incorporation of human experience and the understanding of its natural language. The general aim of this paper is focused on the detailed design of fuzzy logic control, considering the characteristics of the power converters. Finally, several tests is carried out to verify the proper functioning of the proposed fuzzy logic control, which is compared to a traditional PI control.
{"title":"Adjustment strategy of a fuzzy control to integrate renewable sources and storage devices in microgrids","authors":"L. Castro, M. López, J. Mora-Flórez","doi":"10.1109/PEPQA.2019.8851561","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851561","url":null,"abstract":"This paper proposes the design of Fuzzy logic control applied to the outer loop of a voltage source converter, which is indispensable the integration of renewable sources and storage devices in a micro grid. The fuzzy logic method is implemented in non-linear, uncertain or non-stationary processes, since it is characterized by its ease incorporation of human experience and the understanding of its natural language. The general aim of this paper is focused on the detailed design of fuzzy logic control, considering the characteristics of the power converters. Finally, several tests is carried out to verify the proper functioning of the proposed fuzzy logic control, which is compared to a traditional PI control.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130571472","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851559
M. Bello, A. Maitra, D. Montenegro, D. Gusain
The value-proposition for Microgrids depends largely on the need and application. A Microgrid can be described as a group of interconnected loads and distributed energy resources (DER) inside some distinct electrical boundaries that act as a single controllable unit relating to the grid. It should be capable of safe transitioning from the grid and reconnection back to the grid; with the voltages, frequency, etc. of all devices still operating within their allowed limits. Although system resilience and continuous supply is one of the main proponents for the establishment of microgrids, it could also be used to electrify an off grid or remote area, far from the grid. The mode of operation as well as generation types and sources, together with the current protection devices and schemes, will determine the extent of power system studies that will be conducted when planning and designing a Microgrid. This paper highlights the typical power system studies that needs to be considered, when designing aa Microgrid.
{"title":"Power system studies considerations for Microgrid design","authors":"M. Bello, A. Maitra, D. Montenegro, D. Gusain","doi":"10.1109/PEPQA.2019.8851559","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851559","url":null,"abstract":"The value-proposition for Microgrids depends largely on the need and application. A Microgrid can be described as a group of interconnected loads and distributed energy resources (DER) inside some distinct electrical boundaries that act as a single controllable unit relating to the grid. It should be capable of safe transitioning from the grid and reconnection back to the grid; with the voltages, frequency, etc. of all devices still operating within their allowed limits. Although system resilience and continuous supply is one of the main proponents for the establishment of microgrids, it could also be used to electrify an off grid or remote area, far from the grid. The mode of operation as well as generation types and sources, together with the current protection devices and schemes, will determine the extent of power system studies that will be conducted when planning and designing a Microgrid. This paper highlights the typical power system studies that needs to be considered, when designing aa Microgrid.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"17 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122511084","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851569
Manuel D. Trujillo, S. Méndez, G. Ramos, J. Camarillo-Peñaranda, Esteban Jurado
As power generation is moving to a distributed paradigm, an issue that arises is that converters do not provide any inertia. A possible solution is using a converter that mimics the behavior of a synchronous generator, i.e. a synchronverter. The implementation and simulation of a synchronverter is presented in this work. The simulation is performed by doing a real-time simulation between OPAL-RT and NI MyRIO platforms. These modules are used to build the synchronverter, which is connected to the grid and other synchronverter. Analysis based on the frequency, voltage, current and power are performed, for both transient and steady state. Finally, sensibility tests are carried out. Synchronverter demonstrates good overall performance and shows as a feasible way to improve the integration of converter-dependant renewable sources.
{"title":"Real-time Simulation of Synchronverter Connected to the Main Grid","authors":"Manuel D. Trujillo, S. Méndez, G. Ramos, J. Camarillo-Peñaranda, Esteban Jurado","doi":"10.1109/PEPQA.2019.8851569","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851569","url":null,"abstract":"As power generation is moving to a distributed paradigm, an issue that arises is that converters do not provide any inertia. A possible solution is using a converter that mimics the behavior of a synchronous generator, i.e. a synchronverter. The implementation and simulation of a synchronverter is presented in this work. The simulation is performed by doing a real-time simulation between OPAL-RT and NI MyRIO platforms. These modules are used to build the synchronverter, which is connected to the grid and other synchronverter. Analysis based on the frequency, voltage, current and power are performed, for both transient and steady state. Finally, sensibility tests are carried out. Synchronverter demonstrates good overall performance and shows as a feasible way to improve the integration of converter-dependant renewable sources.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122774911","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 : 2019-05-01DOI: 10.1109/PEPQA.2019.8851541
C. Rojas-Montano, A. Ustariz-Farfán, E. Cano-Plata
This paper presents a proposal of voltage sag detection algorithm based on cumulative sums algorithms (CUSUM) and harmonic component decomposition of Tensor Theory (TT) unified index through Kalman Filter (KF). Algorithm provide a reduce computational burden at same time it granted small detection delays and high-effectivity detection respect to state-of-the-art sag detection algorithms. Computational burden reduction was possible by using of TT voltage representation and reduction of the KF order. Abrupt changes on TT representation and rapid estimation on KF permit evidence a large deviation on signal probability function parameters (PFP) during voltage sag. Two-sided CUSUM algorithm take advantage of PFP deviations to make fast and accurate detection. Test for proposal and state-of-the-art algorithms was development. A large voltage sag record data base was used to test algorithms performance under low sampling conditions. Effectiveness, accuracy and computational burden were the test approaches.
{"title":"Voltage Sag Detection Based on PDF Parameters Changes in Tensor Index","authors":"C. Rojas-Montano, A. Ustariz-Farfán, E. Cano-Plata","doi":"10.1109/PEPQA.2019.8851541","DOIUrl":"https://doi.org/10.1109/PEPQA.2019.8851541","url":null,"abstract":"This paper presents a proposal of voltage sag detection algorithm based on cumulative sums algorithms (CUSUM) and harmonic component decomposition of Tensor Theory (TT) unified index through Kalman Filter (KF). Algorithm provide a reduce computational burden at same time it granted small detection delays and high-effectivity detection respect to state-of-the-art sag detection algorithms. Computational burden reduction was possible by using of TT voltage representation and reduction of the KF order. Abrupt changes on TT representation and rapid estimation on KF permit evidence a large deviation on signal probability function parameters (PFP) during voltage sag. Two-sided CUSUM algorithm take advantage of PFP deviations to make fast and accurate detection. Test for proposal and state-of-the-art algorithms was development. A large voltage sag record data base was used to test algorithms performance under low sampling conditions. Effectiveness, accuracy and computational burden were the test approaches.","PeriodicalId":192905,"journal":{"name":"2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127303511","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：