Pub Date : 2018-10-01DOI: 10.1109/EPEC.2018.8598299
Hisham Alharbi, Kankar Bhattacharya
In this paper, investment decisions on storage system installations by a third-party investor in a microgrid is studied. The optimal storage power rating, energy capacity, and the year of installation are determined while maximizing the investor's profit and simultaneously minimizing the microigrd operational cost. The multi-objective problem is solved using a goal programming approach with a weight assigned to each objective. The energy storage is modeled to participate in energy arbitrage and provisions for operating reserves to the microgrid. The storage system performance parameters are considered, and its capacity degradation over the planning horizon is modeled. The results show the effectiveness of the proposed approach and demonstrate the storage system investment decisions in different microgrid operational scenarios.
{"title":"A Goal Programming Approach to Sizing and Timing of Third Party Investments in Storage System for Microgrids","authors":"Hisham Alharbi, Kankar Bhattacharya","doi":"10.1109/EPEC.2018.8598299","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598299","url":null,"abstract":"In this paper, investment decisions on storage system installations by a third-party investor in a microgrid is studied. The optimal storage power rating, energy capacity, and the year of installation are determined while maximizing the investor's profit and simultaneously minimizing the microigrd operational cost. The multi-objective problem is solved using a goal programming approach with a weight assigned to each objective. The energy storage is modeled to participate in energy arbitrage and provisions for operating reserves to the microgrid. The storage system performance parameters are considered, and its capacity degradation over the planning horizon is modeled. The results show the effectiveness of the proposed approach and demonstrate the storage system investment decisions in different microgrid operational scenarios.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122306224","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598378
M. Drahosová, P. Balco, Lukas K. Pokorny, Ryan Razani
This paper presents a clear relationship between agglomeration, smart cities and waste management in Slovak republic. The main contribution of this work is to investigate the relationship between smart cities management and the wastewater coming from the households to waste water treatment plant. It has been shown that the gathered information from the waste water is very useful for identifying the locations of pollution caused by medicaments and drugs in a city. We provide a brief overview of smart cities, followed by statistical information about world's population and the population of cities within Slovak republic. Moreover, the key information about the locations and the times of pollution is briefly discussed. Exploiting the network theory and the tree data structure used in this work, enables one to localize the collection points and to create the infrastructure for automatized collection of data. Compared to previous work, we identify the pollution points more effectively and more economically. Therefore, this makes the solution attractive for criminology of drug distribution points in the city. Subsequently, it leads to cleaner, safer and more environmentally friendly cities.
{"title":"The Waste Water as a Source of Information for the Urban Agglomerations Management","authors":"M. Drahosová, P. Balco, Lukas K. Pokorny, Ryan Razani","doi":"10.1109/EPEC.2018.8598378","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598378","url":null,"abstract":"This paper presents a clear relationship between agglomeration, smart cities and waste management in Slovak republic. The main contribution of this work is to investigate the relationship between smart cities management and the wastewater coming from the households to waste water treatment plant. It has been shown that the gathered information from the waste water is very useful for identifying the locations of pollution caused by medicaments and drugs in a city. We provide a brief overview of smart cities, followed by statistical information about world's population and the population of cities within Slovak republic. Moreover, the key information about the locations and the times of pollution is briefly discussed. Exploiting the network theory and the tree data structure used in this work, enables one to localize the collection points and to create the infrastructure for automatized collection of data. Compared to previous work, we identify the pollution points more effectively and more economically. Therefore, this makes the solution attractive for criminology of drug distribution points in the city. Subsequently, it leads to cleaner, safer and more environmentally friendly cities.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128055016","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598460
Ali R. Al-Roomi, M. El-Hawary
To model the operating cost of thermal generating units, it is common to use polynomial relations between their power output and fuel input. These mathematical relations are known as fuel-cost functions, which are the heart of optimization algorithms. These functions could be modeled as first, second, or third order polynomial equations. The first order or linear equation is weak to explain the variability of units' operating cost. Also, the third order or cubic polynomial equation is rarely used in the literature, because its third element does not have any significant contribution to add. Thus, the second order or quadratic polynomial equation becomes the most popular fuel-cost function. Sometimes, different linear equations grouped as a piecewise function are used to accelerate the computational speed and linear programming algorithms can be directly involved. This study tries to achieve the goal of the last approach without using any piecewise function. That is, improving the preceding single linear equation to be a competitive fuel-cost function.
{"title":"How to Improve Linear Fuel-Cost Function to Compete with Quadratic and Cubic Functions","authors":"Ali R. Al-Roomi, M. El-Hawary","doi":"10.1109/EPEC.2018.8598460","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598460","url":null,"abstract":"To model the operating cost of thermal generating units, it is common to use polynomial relations between their power output and fuel input. These mathematical relations are known as fuel-cost functions, which are the heart of optimization algorithms. These functions could be modeled as first, second, or third order polynomial equations. The first order or linear equation is weak to explain the variability of units' operating cost. Also, the third order or cubic polynomial equation is rarely used in the literature, because its third element does not have any significant contribution to add. Thus, the second order or quadratic polynomial equation becomes the most popular fuel-cost function. Sometimes, different linear equations grouped as a piecewise function are used to accelerate the computational speed and linear programming algorithms can be directly involved. This study tries to achieve the goal of the last approach without using any piecewise function. That is, improving the preceding single linear equation to be a competitive fuel-cost function.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132822652","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598319
A. Abdi, Sharareh Taahipour
Many nations are implementing or plan to implement a carbon pricing program in response to global warming and climate change issues. A significant amount of greenhouse gas (GHG) emissions can be attributed to projects, mainly construction works. Therefore, projects' environmental impact should be estimated before the project commencement and be monitored during its implementation phase. In this paper, we propose a probabilistic model to quantify the uncertainty of project GHG emissions using Bayesian networks (BNs) and simulation techniques. The model provides a quantitative risk analysis mechanism to estimate the total emissions of the project as well as an update of the final emissions using information on the completed activates.
{"title":"Uncertanty Analysis of Project Emissions","authors":"A. Abdi, Sharareh Taahipour","doi":"10.1109/EPEC.2018.8598319","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598319","url":null,"abstract":"Many nations are implementing or plan to implement a carbon pricing program in response to global warming and climate change issues. A significant amount of greenhouse gas (GHG) emissions can be attributed to projects, mainly construction works. Therefore, projects' environmental impact should be estimated before the project commencement and be monitored during its implementation phase. In this paper, we propose a probabilistic model to quantify the uncertainty of project GHG emissions using Bayesian networks (BNs) and simulation techniques. The model provides a quantitative risk analysis mechanism to estimate the total emissions of the project as well as an update of the final emissions using information on the completed activates.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131971054","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598368
M. Gray, W. Morsi
This paper presents a transactive energy (TE) control of residential home battery energy storage systems that compensates residential prosumers for the rescheduling of the charging and discharging of their batteries. The proposed TE framework is evaluated in terms of the annual distribution transformer loss of life reduction and the economic cost to the distribution system operator considering the effect of prosumers owning plug-in electric vehicles with consideration of both time-of-use (TOU) and distributed locational marginal pricing (DLMP) schemes. The results have shown that in case of DLMP pricing the distribution transformer's aging was almost doubled when compared to TOU pricing schemes. Moreover, the application of the proposed TE framework results in extending the lifetime of the distribution transformers under both pricing schemes. Further results have shown that the cost to the electric utility to perform control action is nearly double when using TOU pricing rates versus the rates based on the DLMP pricing. Finally, the annual active power losses in the system were reduced through the proposed TE control framework by up to 2% in the case of DLMP pricing.
{"title":"A Novel Transactive Energy Framework for Prosumers with Battery Storage and Electric Vehicles","authors":"M. Gray, W. Morsi","doi":"10.1109/EPEC.2018.8598368","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598368","url":null,"abstract":"This paper presents a transactive energy (TE) control of residential home battery energy storage systems that compensates residential prosumers for the rescheduling of the charging and discharging of their batteries. The proposed TE framework is evaluated in terms of the annual distribution transformer loss of life reduction and the economic cost to the distribution system operator considering the effect of prosumers owning plug-in electric vehicles with consideration of both time-of-use (TOU) and distributed locational marginal pricing (DLMP) schemes. The results have shown that in case of DLMP pricing the distribution transformer's aging was almost doubled when compared to TOU pricing schemes. Moreover, the application of the proposed TE framework results in extending the lifetime of the distribution transformers under both pricing schemes. Further results have shown that the cost to the electric utility to perform control action is nearly double when using TOU pricing rates versus the rates based on the DLMP pricing. Finally, the annual active power losses in the system were reduced through the proposed TE control framework by up to 2% in the case of DLMP pricing.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134180735","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598380
Amjad Iqbal, T. Iqbal
Modern trend., towards renewable energy sources has complicated our power systemS’ network with the distributed generation and its control. The major challenge of this network is to implement a low cost, secure and authentic communication system between Supervisory Control and Data Acquisition (SCADA) unit and Remote End Devices (RED). This paper addresses the issues of security and authenticity for wireless communication for SCADA system. Algorithm of Advanced Encryption Standard (AES) has been implemented on ESP32 with LoRa module to secure the wireless communication for micro-grids and authenticity has been achieved by generating unique Message Authentication Code (MAC). A point to point communication setup has been developed with range above 10km and cost less than $40 with power consumption of 5mW.
{"title":"Low-cost and Secure Communication System for Remote Micro-grids using AES Cryptography on ESP32 with LoRa Module","authors":"Amjad Iqbal, T. Iqbal","doi":"10.1109/EPEC.2018.8598380","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598380","url":null,"abstract":"Modern trend., towards renewable energy sources has complicated our power systemS’ network with the distributed generation and its control. The major challenge of this network is to implement a low cost, secure and authentic communication system between Supervisory Control and Data Acquisition (SCADA) unit and Remote End Devices (RED). This paper addresses the issues of security and authenticity for wireless communication for SCADA system. Algorithm of Advanced Encryption Standard (AES) has been implemented on ESP32 with LoRa module to secure the wireless communication for micro-grids and authenticity has been achieved by generating unique Message Authentication Code (MAC). A point to point communication setup has been developed with range above 10km and cost less than $40 with power consumption of 5mW.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134367135","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598298
Khaled Alshammari, Hasan Alrajhi, R. Shatshat
This paper presents an optimal power flow (OPF) analysis of a multi-terminal high-voltage direct current (HVDC) system. The objective of the OPF analysis in this paper is to minimize not only the losses in the lines and the converters but also the generation cost by using a multi-objective function, which makes the system economically efficient. The constraints of voltages, both of the DC and AC power flows, and the line flows are the parameters that affect the optimization process. The proposed methodology covers both the AC and DC sides of the grid in terms of the lines as well as the DC/DC and AC/DC converter losses. In order to achieve a global optimal solution of the OPF problem, semidefinite programming (SDP) is used. SDP has been tested on an 8-bus system with one DC/DC converter and five AC/DC converters. The result of the optimization process is obtained and a comparison is made between neglecting and including the losses of the AC/DC and DC/DC converters.
{"title":"Optimal Power Flow in Multi -Terminal HVDC Systems","authors":"Khaled Alshammari, Hasan Alrajhi, R. Shatshat","doi":"10.1109/EPEC.2018.8598298","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598298","url":null,"abstract":"This paper presents an optimal power flow (OPF) analysis of a multi-terminal high-voltage direct current (HVDC) system. The objective of the OPF analysis in this paper is to minimize not only the losses in the lines and the converters but also the generation cost by using a multi-objective function, which makes the system economically efficient. The constraints of voltages, both of the DC and AC power flows, and the line flows are the parameters that affect the optimization process. The proposed methodology covers both the AC and DC sides of the grid in terms of the lines as well as the DC/DC and AC/DC converter losses. In order to achieve a global optimal solution of the OPF problem, semidefinite programming (SDP) is used. SDP has been tested on an 8-bus system with one DC/DC converter and five AC/DC converters. The result of the optimization process is obtained and a comparison is made between neglecting and including the losses of the AC/DC and DC/DC converters.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134438298","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598370
C. Yapa, U. Annakkage, S. Filizadeh
This paper presents a linearized state-space model of the hybrid cascaded modular multilevel voltage source converter. The developed model is validated against a detailed non-linear Electromagnetic Transient (EMT) simulation model. The impact of the ac system strength on the performance of the converter is investigated for moderately strong and weak systems. An eigenvalue analysis is conducted for both scenarios, with focus on the oscillatory modes present in the system in order to evaluate the stability constraints of the converter when connected to ac networks of different strengths.
{"title":"Stability Analysis of a Hybrid Modular Multilevel Voltage Source Converter","authors":"C. Yapa, U. Annakkage, S. Filizadeh","doi":"10.1109/EPEC.2018.8598370","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598370","url":null,"abstract":"This paper presents a linearized state-space model of the hybrid cascaded modular multilevel voltage source converter. The developed model is validated against a detailed non-linear Electromagnetic Transient (EMT) simulation model. The impact of the ac system strength on the performance of the converter is investigated for moderately strong and weak systems. An eigenvalue analysis is conducted for both scenarios, with focus on the oscillatory modes present in the system in order to evaluate the stability constraints of the converter when connected to ac networks of different strengths.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125148858","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598310
Roozbeh Sadeghi, A. Knight
In this paper, the subsynchronous resonance (SSR) is investigated using LabViewand Matlab/Simulink based on the Simscape Power Systems tool. The simulation model in this paper is designed to identify, characterize and mitigate low frequency oscillations in power systems. The results obtained verify the effect of series compensation level on subsynchronous frequencies. The research in this paper represents the results of emulating SSR using hardware and software implementation. It then describes subsynchronous resonance studies that should be performed for each series compensation level. Technical descriptions and implementation model are provided.
本文基于Simscape Power Systems工具，利用labview和Matlab/Simulink对次同步谐振(SSR)进行了研究。本文的仿真模型旨在识别、表征和缓解电力系统中的低频振荡。仿真结果验证了串联补偿电平对次同步频率的影响。本文的研究是通过硬件和软件实现对SSR进行仿真的结果。然后描述了应该对每个串联补偿水平执行的次同步谐振研究。给出了技术描述和实现模型。
{"title":"Emulating Subsynchronous Resonance using Hardware and Software Implementation","authors":"Roozbeh Sadeghi, A. Knight","doi":"10.1109/EPEC.2018.8598310","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598310","url":null,"abstract":"In this paper, the subsynchronous resonance (SSR) is investigated using LabViewand Matlab/Simulink based on the Simscape Power Systems tool. The simulation model in this paper is designed to identify, characterize and mitigate low frequency oscillations in power systems. The results obtained verify the effect of series compensation level on subsynchronous frequencies. The research in this paper represents the results of emulating SSR using hardware and software implementation. It then describes subsynchronous resonance studies that should be performed for each series compensation level. Technical descriptions and implementation model are provided.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114549564","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 : 2018-10-01DOI: 10.1109/EPEC.2018.8598293
A. Pathirana, A. Rajapakse, A. C. Adewole
This paper describes implementation of a hybrid protection scheme consisting of both transient-based protection and conventional time over-current protection in a laboratory environment. Transient base protection scheme uses initial polarities of current transients to determine whether a fault is in the protected zone, while the conventional protection scheme confirms the existence of fault. The scope of testing is limited to testing the functionality and generic performance characteristics of hybrid protection scheme. The implementation consists of both hardware and software sections including power system modelling, sensor designing and programming of the conventional relay logic. The operation of the hybrid protection scheme is demonstrated using hardware-in-the-loop simulations.
{"title":"Implementation and Testing of a Hybrid Protection Scheme for Active Distribution Network","authors":"A. Pathirana, A. Rajapakse, A. C. Adewole","doi":"10.1109/EPEC.2018.8598293","DOIUrl":"https://doi.org/10.1109/EPEC.2018.8598293","url":null,"abstract":"This paper describes implementation of a hybrid protection scheme consisting of both transient-based protection and conventional time over-current protection in a laboratory environment. Transient base protection scheme uses initial polarities of current transients to determine whether a fault is in the protected zone, while the conventional protection scheme confirms the existence of fault. The scope of testing is limited to testing the functionality and generic performance characteristics of hybrid protection scheme. The implementation consists of both hardware and software sections including power system modelling, sensor designing and programming of the conventional relay logic. The operation of the hybrid protection scheme is demonstrated using hardware-in-the-loop simulations.","PeriodicalId":265297,"journal":{"name":"2018 IEEE Electrical Power and Energy Conference (EPEC)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114405396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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