Pub Date : 2016-07-17DOI: 10.1109/PESGM.2016.7741260
Ling Wu, Yong Liu, D. Zhou, Jiahui Guo, Yilu Liu
Frequency monitoring network (FNET/GridEye), a wide-area monitoring system (WAMS) at distribution level, is known to be able to reveal many insights of power grid dynamics through the real time phasor measurement collected by frequency disturbance recorders (FDRs). A large number of FDR units are currently deployed in several power grids worldwide. This paper focuses on the inertial frequency responses of various bulk power grids over the world based on the observation of FNET/GridEye. It is the first time this kind of research is extended to main power grids worldwide. This paper discloses the frequency response characteristics for different sizes of power grids.
{"title":"Observation of inertial frequency response of main power grids worldwide using FNET/GridEye","authors":"Ling Wu, Yong Liu, D. Zhou, Jiahui Guo, Yilu Liu","doi":"10.1109/PESGM.2016.7741260","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741260","url":null,"abstract":"Frequency monitoring network (FNET/GridEye), a wide-area monitoring system (WAMS) at distribution level, is known to be able to reveal many insights of power grid dynamics through the real time phasor measurement collected by frequency disturbance recorders (FDRs). A large number of FDR units are currently deployed in several power grids worldwide. This paper focuses on the inertial frequency responses of various bulk power grids over the world based on the observation of FNET/GridEye. It is the first time this kind of research is extended to main power grids worldwide. This paper discloses the frequency response characteristics for different sizes of power grids.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127730329","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741156
Mikhail A. Bragin, P. Luh, Joseph H. Yan, G. Stern
Unit Commitment and Economic Dispatch (UCED) with combined cycle (CC) units and AC power flow is an important problem to be solved by ISOs. The problem is difficult because of complicated transitions in CC units and highly non-linear AC power flows. Currently, to solve the problem, transitions among CC states are simplified and AC power flow is approximated with DC power flow. However, the resulting solution may not be consistent with actual operations of power systems. In this paper, a more operational approach of modeling UCED with CC units and AC power flow is developed. Under the frequently used assumption of low network resistance, AC power flow is represented as a monotonic function. Then, the original problem is solved by exploiting the monotonicity through the novel dynamic linearization technique and separability after relaxing coupling system-wide demand constraints. The complexity of resulting subproblems is drastically reduced and linearity is efficiently exploited by using branch-and-cut. Subproblem solutions are efficiently coordinated by our recently developed surrogate Lagrangian relaxation and convergence is guaranteed. Based on a 30-bus system, numerical results demonstrate the new approach is more computationally efficient as compared to Benders decomposition.
{"title":"An efficient approach for Unit Commitment and Economic Dispatch with combined cycle units and AC Power Flow","authors":"Mikhail A. Bragin, P. Luh, Joseph H. Yan, G. Stern","doi":"10.1109/PESGM.2016.7741156","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741156","url":null,"abstract":"Unit Commitment and Economic Dispatch (UCED) with combined cycle (CC) units and AC power flow is an important problem to be solved by ISOs. The problem is difficult because of complicated transitions in CC units and highly non-linear AC power flows. Currently, to solve the problem, transitions among CC states are simplified and AC power flow is approximated with DC power flow. However, the resulting solution may not be consistent with actual operations of power systems. In this paper, a more operational approach of modeling UCED with CC units and AC power flow is developed. Under the frequently used assumption of low network resistance, AC power flow is represented as a monotonic function. Then, the original problem is solved by exploiting the monotonicity through the novel dynamic linearization technique and separability after relaxing coupling system-wide demand constraints. The complexity of resulting subproblems is drastically reduced and linearity is efficiently exploited by using branch-and-cut. Subproblem solutions are efficiently coordinated by our recently developed surrogate Lagrangian relaxation and convergence is guaranteed. Based on a 30-bus system, numerical results demonstrate the new approach is more computationally efficient as compared to Benders decomposition.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126436981","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741207
H. Dagdougui, L. Dessaint, G. Gagnon, K. Al-haddad
In this paper, we propose a system design for a university campus microgrid (UCM) to facilitate research needs in relation to the operation and control of microgrid. This paper proposes the design, modeling and optimal operation of a UCM. The optimal operation aims to minimize the operation costs of photovoltaic system and costs of exchange with the local electrical network. The UCM is aggregating different distributed energy resources with parts of local loads that are co-located in the campus setting. The mathematical modeling of different components of the UCM is proposed. However, the objective of the UCM is to achieve three objectives: 1) to satisfy part of the residential campus loads, 2) to charge employees electric vehicles and 3) to help the campus avoiding peak load in period of high demands.
{"title":"Modeling and optimal operation of a university campus microgrid","authors":"H. Dagdougui, L. Dessaint, G. Gagnon, K. Al-haddad","doi":"10.1109/PESGM.2016.7741207","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741207","url":null,"abstract":"In this paper, we propose a system design for a university campus microgrid (UCM) to facilitate research needs in relation to the operation and control of microgrid. This paper proposes the design, modeling and optimal operation of a UCM. The optimal operation aims to minimize the operation costs of photovoltaic system and costs of exchange with the local electrical network. The UCM is aggregating different distributed energy resources with parts of local loads that are co-located in the campus setting. The mathematical modeling of different components of the UCM is proposed. However, the objective of the UCM is to achieve three objectives: 1) to satisfy part of the residential campus loads, 2) to charge employees electric vehicles and 3) to help the campus avoiding peak load in period of high demands.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128112729","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741871
Qin Yan, T. Dokic, M. Kezunovic
This study evaluates the outage probability and electricity customer cost under the potential weather caused power blackouts. Risk assessment of the weather impact on customers is implemented and visualized in ArcGIS map. The methodology correlates the historical large power outage events with the corresponding weather condition of the time, uses weather forecast data to assess the risk for customers, and compares the results in different predicted weather conditions.
{"title":"Predicting impact of weather caused blackouts on electricity customers based on risk assessment","authors":"Qin Yan, T. Dokic, M. Kezunovic","doi":"10.1109/PESGM.2016.7741871","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741871","url":null,"abstract":"This study evaluates the outage probability and electricity customer cost under the potential weather caused power blackouts. Risk assessment of the weather impact on customers is implemented and visualized in ArcGIS map. The methodology correlates the historical large power outage events with the corresponding weather condition of the time, uses weather forecast data to assess the risk for customers, and compares the results in different predicted weather conditions.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121862717","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741835
Yanling Lin, Tao Ding, Z. Bie, Gengfeng Li
As photovoltaic (PV) integration increases in distribution systems, an effective way of assessing the maximum allowable PV integration capacity is urgently needed. In this paper, a new method is proposed to evaluate the maximum PV integration capacity with AC power flow limits, and the effect of topology reconfiguration on PV integration is also considered. In addition, the single commodity flow constraint is put forward to guarantee topology radiality. Usually, this problem requires mix integer non-convex optimization, which is a great challenge to solve. To address this problem, second order cones are employed to relax the non-convex constraints so that the model can be efficiently solved. Furthermore, the IEEE 33-bus test system with four PV integration cases for maximum integration capacity is studied. The test result shows the effectiveness of reconfiguration in increasing maximum PV integration capacity.
{"title":"A new method to evaluate maximum capacity of photovoltaic integration considering network topology reconfiguration","authors":"Yanling Lin, Tao Ding, Z. Bie, Gengfeng Li","doi":"10.1109/PESGM.2016.7741835","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741835","url":null,"abstract":"As photovoltaic (PV) integration increases in distribution systems, an effective way of assessing the maximum allowable PV integration capacity is urgently needed. In this paper, a new method is proposed to evaluate the maximum PV integration capacity with AC power flow limits, and the effect of topology reconfiguration on PV integration is also considered. In addition, the single commodity flow constraint is put forward to guarantee topology radiality. Usually, this problem requires mix integer non-convex optimization, which is a great challenge to solve. To address this problem, second order cones are employed to relax the non-convex constraints so that the model can be efficiently solved. Furthermore, the IEEE 33-bus test system with four PV integration cases for maximum integration capacity is studied. The test result shows the effectiveness of reconfiguration in increasing maximum PV integration capacity.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"19 3‐4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132340723","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741801
Jin-quan Zhao, X. Liu, Changnian Lin, Wenhui Wei
Extensive penetration of single phase distributed generators (DGs) such as photovoltaic generations may cause serious phase unbalance problems in distribution networks. The phase unbalance condition will make voltage/VAR optimization problem difficult to be solved by using traditional model and methods for balanced distribution networks. A three-phase unbalanced voltage/VAR optimization model for active distribution networks is proposed in this paper. The OLTC transformers and distributed reactive power resources such as static VAR compensators, embedded generators and capacitors banks are considered as control devices to minimize the negative sequence system voltages and network losses. The voltage/VAR optimization problem is formulated as a mixed-integer quadratic constrains quadratic programming (MIQCQP) problem in rectangular coordinates. The optimal solution is obtained by solving the MIQCQP problem using the branch-bound and primal-dual interior point method. Simulation results of the modified IEEE 33-bus test system demonstrate that the proposed model and method are effective.
{"title":"Three-phase unbalanced voltage/VAR optimization for active distribution networks","authors":"Jin-quan Zhao, X. Liu, Changnian Lin, Wenhui Wei","doi":"10.1109/PESGM.2016.7741801","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741801","url":null,"abstract":"Extensive penetration of single phase distributed generators (DGs) such as photovoltaic generations may cause serious phase unbalance problems in distribution networks. The phase unbalance condition will make voltage/VAR optimization problem difficult to be solved by using traditional model and methods for balanced distribution networks. A three-phase unbalanced voltage/VAR optimization model for active distribution networks is proposed in this paper. The OLTC transformers and distributed reactive power resources such as static VAR compensators, embedded generators and capacitors banks are considered as control devices to minimize the negative sequence system voltages and network losses. The voltage/VAR optimization problem is formulated as a mixed-integer quadratic constrains quadratic programming (MIQCQP) problem in rectangular coordinates. The optimal solution is obtained by solving the MIQCQP problem using the branch-bound and primal-dual interior point method. Simulation results of the modified IEEE 33-bus test system demonstrate that the proposed model and method are effective.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132457270","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741272
Yannan Sun, Z. Hou, Da Meng, N. Samaan, Y. Makarov, Zhenyu Huang
In this study, we represent and reduce the uncertainties in short-term load forecasting by integrating time series analysis tools including ARIMA modeling, sequential Gaussian simulation, and principal component analysis. The approaches are mainly focusing on maintaining the interdependency between multiple geographically related areas. These approaches are applied onto cross-correlated load time series as well as their forecast errors. Multiple short-term prediction realizations are then generated from the reduced uncertainty ranges, which are useful for power system risk analyses1.
{"title":"Quantifying and reducing uncertainty in correlated multi-area short-term load forecasting","authors":"Yannan Sun, Z. Hou, Da Meng, N. Samaan, Y. Makarov, Zhenyu Huang","doi":"10.1109/PESGM.2016.7741272","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741272","url":null,"abstract":"In this study, we represent and reduce the uncertainties in short-term load forecasting by integrating time series analysis tools including ARIMA modeling, sequential Gaussian simulation, and principal component analysis. The approaches are mainly focusing on maintaining the interdependency between multiple geographically related areas. These approaches are applied onto cross-correlated load time series as well as their forecast errors. Multiple short-term prediction realizations are then generated from the reduced uncertainty ranges, which are useful for power system risk analyses1.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130007244","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741839
A. Moraco, Marley F. Tavares, E. Geraldi, R. Ramos
In this paper, an approach to evaluate the occurrence of flicker induced by electromechanical oscillations is proposed. This approach employs the extended participation factors (EPF) to statistically quantify the presence of electromechanical modes in the dynamics of the terminal voltage of a distributed synchronous generator. Once the results obtained by the EPF indicate a high probability for the manifestation of the electromechanical mode in the terminal voltage of the distributed generator, an estimate for the probability of occurrence of flicker can be obtained.
{"title":"An approach to evaluate the occurrence of flicker induced by electromechanical oscillations","authors":"A. Moraco, Marley F. Tavares, E. Geraldi, R. Ramos","doi":"10.1109/PESGM.2016.7741839","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741839","url":null,"abstract":"In this paper, an approach to evaluate the occurrence of flicker induced by electromechanical oscillations is proposed. This approach employs the extended participation factors (EPF) to statistically quantify the presence of electromechanical modes in the dynamics of the terminal voltage of a distributed synchronous generator. Once the results obtained by the EPF indicate a high probability for the manifestation of the electromechanical mode in the terminal voltage of the distributed generator, an estimate for the probability of occurrence of flicker can be obtained.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131644584","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741188
C. Lashway, A. Elsayed, O. Mohammed
As the electric vehicle (EV) gains traction in the modern automotive market, a focus has been placed on the development of efficient and long-lasting methods to store energy. In order to exploit the advantages of a hybrid energy storage system (HESS), new management schemes are needed which understand the mechanics of each energy storage device. Many EVs have introduced regenerative braking as a method to recharge the battery bank while in operation. Unfortunately, the combination of long duration discharge drive currents and short, high powered charging currents from regenerative breaking place batteries under enormous stress resulting in shorter lifetimes. Moreover, when the battery bank is at a high state of charge, electrochemical constraints will limit current injection during regenerative braking thus some energy is left to waste. In this work, a parallel-connected lithium ion battery bank and supercapacitor HESS demonstrates a new multi-state EV control and management scheme. Unnecessary cycling of the lithium ion battery array is reduced while the efficiency of a regenerative braking pulse is increased. The scheme is demonstrated experimentally using the DOE Hybrid Pulsed Power Characterization test profile procedure.
{"title":"Management scheme for parallel connected hybrid energy storage in electric vehicles","authors":"C. Lashway, A. Elsayed, O. Mohammed","doi":"10.1109/PESGM.2016.7741188","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741188","url":null,"abstract":"As the electric vehicle (EV) gains traction in the modern automotive market, a focus has been placed on the development of efficient and long-lasting methods to store energy. In order to exploit the advantages of a hybrid energy storage system (HESS), new management schemes are needed which understand the mechanics of each energy storage device. Many EVs have introduced regenerative braking as a method to recharge the battery bank while in operation. Unfortunately, the combination of long duration discharge drive currents and short, high powered charging currents from regenerative breaking place batteries under enormous stress resulting in shorter lifetimes. Moreover, when the battery bank is at a high state of charge, electrochemical constraints will limit current injection during regenerative braking thus some energy is left to waste. In this work, a parallel-connected lithium ion battery bank and supercapacitor HESS demonstrates a new multi-state EV control and management scheme. Unnecessary cycling of the lithium ion battery array is reduced while the efficiency of a regenerative braking pulse is increased. The scheme is demonstrated experimentally using the DOE Hybrid Pulsed Power Characterization test profile procedure.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132974986","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 : 2016-07-17DOI: 10.1109/PESGM.2016.7741520
M. Lecouvez, R. Falgout, C. Woodward, P. Top
This paper presents a fully multilevel approach to parallel in time solution of transient power system simulations. The method employs a multigrid reduction algorithm in time parallelized using the MPI distributed memory programming model. The method is demonstrated on a simple Single Machine Infinite Bus differential-algebraic equation model problem, for which speedup is obtained for as few as 8 processing cores on a problem with 10,000 time steps. Speedup of a factor of 13 is observed for a 100,000 step version of this simple problem. Based on these results, we expect significantly better speedup on larger problems where more work is available to each processor allowing greater amortization of the parallel communication.
{"title":"A parallel multigrid reduction in time method for power systems","authors":"M. Lecouvez, R. Falgout, C. Woodward, P. Top","doi":"10.1109/PESGM.2016.7741520","DOIUrl":"https://doi.org/10.1109/PESGM.2016.7741520","url":null,"abstract":"This paper presents a fully multilevel approach to parallel in time solution of transient power system simulations. The method employs a multigrid reduction algorithm in time parallelized using the MPI distributed memory programming model. The method is demonstrated on a simple Single Machine Infinite Bus differential-algebraic equation model problem, for which speedup is obtained for as few as 8 processing cores on a problem with 10,000 time steps. Speedup of a factor of 13 is observed for a 100,000 step version of this simple problem. Based on these results, we expect significantly better speedup on larger problems where more work is available to each processor allowing greater amortization of the parallel communication.","PeriodicalId":155315,"journal":{"name":"2016 IEEE Power and Energy Society General Meeting (PESGM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127574254","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：