Pub Date : 2016-12-01DOI: 10.1109/SASG.2016.7849685
R. Rob, Tolga Tural, Gareth McLorn, Abdullahi O Sheikh, Ahmad Hassan
The rapid spread of cyber threats and attacks are forcing many organizations to rethink their cyber security policies and standards. The latest cyber-attacks are well structured, organized, vicious, destructive and exceptionally sophisticated. The new reality of relentless cyber-attacks is causing havoc at a high level within oil and energy companies. There is a great need for developing and establishing new processes and policies with which to train a new “tech savvy” generation of professionals; who can then create and implement solid, systematic and sound cyber security policies. Cyber defense standards cannot be achieved fast enough to deal with this evolving threat.
{"title":"Addressing cyber security for the oil, gas and energy sector","authors":"R. Rob, Tolga Tural, Gareth McLorn, Abdullahi O Sheikh, Ahmad Hassan","doi":"10.1109/SASG.2016.7849685","DOIUrl":"https://doi.org/10.1109/SASG.2016.7849685","url":null,"abstract":"The rapid spread of cyber threats and attacks are forcing many organizations to rethink their cyber security policies and standards. The latest cyber-attacks are well structured, organized, vicious, destructive and exceptionally sophisticated. The new reality of relentless cyber-attacks is causing havoc at a high level within oil and energy companies. There is a great need for developing and establishing new processes and policies with which to train a new “tech savvy” generation of professionals; who can then create and implement solid, systematic and sound cyber security policies. Cyber defense standards cannot be achieved fast enough to deal with this evolving threat.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126887461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965407
J. Iria, F. Soares, A. Madureira
This paper proposes a novel Energy Aggregator model responsible for managing the flexibility of low voltage customers in order to reduce electricity costs. The flexibility of the customers is represented by the availability of their controllable loads to reduce/increase power consumption. The flexible loads are managed according to the customers' preferences and the technical limitations of the flexible loads. The Energy Aggregator model developed includes an algorithm designed to manage customers' flexibility in quasi-real-time, with the objective of minimizing the deviations from the energy bought by the aggregator in the market. A scenario with 30 households located in a semi-urban area is used to illustrate the application of the algorithm and validate the proposed approach.
{"title":"Advanced models and algorithms for demand participation in electricity markets","authors":"J. Iria, F. Soares, A. Madureira","doi":"10.1109/NAPS.2014.6965407","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965407","url":null,"abstract":"This paper proposes a novel Energy Aggregator model responsible for managing the flexibility of low voltage customers in order to reduce electricity costs. The flexibility of the customers is represented by the availability of their controllable loads to reduce/increase power consumption. The flexible loads are managed according to the customers' preferences and the technical limitations of the flexible loads. The Energy Aggregator model developed includes an algorithm designed to manage customers' flexibility in quasi-real-time, with the objective of minimizing the deviations from the energy bought by the aggregator in the market. A scenario with 30 households located in a semi-urban area is used to illustrate the application of the algorithm and validate the proposed approach.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127283395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965356
Carlos M. Luna, P. Moreno, Julián Sotelo, A. Guzman
This paper presents the development of a computer program to analyze multiconductor transmission line fault transients including measurement transformers. The method used here is based on the Numerical Laplace Transform and the superposition principle. Two-port Admittance matrix representation of Non Homogeneous Transmission Lines and measurement transformer models are presented. The frequency domain simulation procedure is compared with results obtained from the commercial simulator PSCAD® (Power System Computer Aided Design).
{"title":"Frequency domain simulation of fault transients in transmission lines including measurement transformers","authors":"Carlos M. Luna, P. Moreno, Julián Sotelo, A. Guzman","doi":"10.1109/NAPS.2014.6965356","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965356","url":null,"abstract":"This paper presents the development of a computer program to analyze multiconductor transmission line fault transients including measurement transformers. The method used here is based on the Numerical Laplace Transform and the superposition principle. Two-port Admittance matrix representation of Non Homogeneous Transmission Lines and measurement transformer models are presented. The frequency domain simulation procedure is compared with results obtained from the commercial simulator PSCAD® (Power System Computer Aided Design).","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121894988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965364
D. P. Montoya, J. M. Ramirez, J. R. Zuluaga
This paper proposes a multi-objective optimization in conjunction with a minimal spanning tree (MST) to solve the reconfiguration problem in parallel with the optimal capacitor allocation. The proposed method is based on a combination of genetic algorithm and the Kruskal Algorithm. The reconfiguration problem is solved through the MST, embedded into a NSGA-II for solving the total problem. An appropriate selection of the fitness functions provides a solution that is able to reduce power loss and improve the voltage profile in the distribution network. To solve the problems, a multi-objective formulation based maximization of the annual savings, minimization of total power loss, and minimization of total voltage deviation on the buses is proposed. The comparative test performed on test systems has demonstrated the accuracy of the proposed algorithm.
{"title":"Multi-objective optimization for reconfiguration and capacitor allocation in distribution systems","authors":"D. P. Montoya, J. M. Ramirez, J. R. Zuluaga","doi":"10.1109/NAPS.2014.6965364","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965364","url":null,"abstract":"This paper proposes a multi-objective optimization in conjunction with a minimal spanning tree (MST) to solve the reconfiguration problem in parallel with the optimal capacitor allocation. The proposed method is based on a combination of genetic algorithm and the Kruskal Algorithm. The reconfiguration problem is solved through the MST, embedded into a NSGA-II for solving the total problem. An appropriate selection of the fitness functions provides a solution that is able to reduce power loss and improve the voltage profile in the distribution network. To solve the problems, a multi-objective formulation based maximization of the annual savings, minimization of total power loss, and minimization of total voltage deviation on the buses is proposed. The comparative test performed on test systems has demonstrated the accuracy of the proposed algorithm.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124559382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965418
Nickolas Gellerman, P. Ranganathan, Ranganath Vallakati, Anupam Mukherjee
This paper uses complex phasor data (voltage, current and phase angle) from openPDC for situational awareness of the SmartGrid. Alarm notification features through E-mail and Short message service (SMS) on various parameters of Phasor Measurement Units (PMU) data has been developed in C# programming as an extension to the existing openPDC software functionalities. In addition, realtime display of PMU data based on the geographical locations of PMU is developed for openPDC software and is presented within a Google Maps-based Windows Forms application. The paper also discusses how to process the PMU data using a k-means clustering algorithm.
{"title":"User interface for situational awareness of openPDC","authors":"Nickolas Gellerman, P. Ranganathan, Ranganath Vallakati, Anupam Mukherjee","doi":"10.1109/NAPS.2014.6965418","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965418","url":null,"abstract":"This paper uses complex phasor data (voltage, current and phase angle) from openPDC for situational awareness of the SmartGrid. Alarm notification features through E-mail and Short message service (SMS) on various parameters of Phasor Measurement Units (PMU) data has been developed in C# programming as an extension to the existing openPDC software functionalities. In addition, realtime display of PMU data based on the geographical locations of PMU is developed for openPDC software and is presented within a Google Maps-based Windows Forms application. The paper also discusses how to process the PMU data using a k-means clustering algorithm.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130622967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965384
K. Baker, G. Hug, Xin Li
With the increasing penetration of renewable energy sources into the electric power grid, a heightened amount of attention is being given to the topic of energy storage, a popular solution to account for the variability of these sources. Energy storage systems (ESS) can also be beneficial for load-levelling and peak-shaving, as well as reducing the ramping of generators. However, the optimal energy and power ratings for these devices is not immediately obvious. In this paper, the energy capacity and power rating of the ESS is optimized using two-stage stochastic optimization. In order to capture the wind and load variations in the different days throughout the year, it is advantageous to use a large number of scenarios. Optimizing generator outputs and storage decisions at the intra-hour level with a high number of scenarios will result in a very large optimization problem, and thus scenario reduction is employed. A relationship between the variance of the system price for each scenario and the optimal storage size determined for that scenario is shown. The correlation between these parameters allows for a natural clustering of similar scenarios. Scenario reduction is performed by exploiting this relationship in conjunction with centroid-linkage clustering, and stochastic optimization with the reduced number of scenarios is used to determine the optimal ESS size.
{"title":"Optimal storage sizing using two-stage stochastic optimization for intra-hourly dispatch","authors":"K. Baker, G. Hug, Xin Li","doi":"10.1109/NAPS.2014.6965384","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965384","url":null,"abstract":"With the increasing penetration of renewable energy sources into the electric power grid, a heightened amount of attention is being given to the topic of energy storage, a popular solution to account for the variability of these sources. Energy storage systems (ESS) can also be beneficial for load-levelling and peak-shaving, as well as reducing the ramping of generators. However, the optimal energy and power ratings for these devices is not immediately obvious. In this paper, the energy capacity and power rating of the ESS is optimized using two-stage stochastic optimization. In order to capture the wind and load variations in the different days throughout the year, it is advantageous to use a large number of scenarios. Optimizing generator outputs and storage decisions at the intra-hour level with a high number of scenarios will result in a very large optimization problem, and thus scenario reduction is employed. A relationship between the variance of the system price for each scenario and the optimal storage size determined for that scenario is shown. The correlation between these parameters allows for a natural clustering of similar scenarios. Scenario reduction is performed by exploiting this relationship in conjunction with centroid-linkage clustering, and stochastic optimization with the reduced number of scenarios is used to determine the optimal ESS size.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124195749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965471
J. Morales, E. Orduña, R. Cabral, A. Bretas
Voltages produced by atmospheric discharges are considered the main causes of electric power outages. The study of atmospheric discharges should be analyzed and studied in order to make good insulator coordination. In this context, Footing Tower Resistance (FTR) is a crucial parameter in lightning strokes studies. FTR performance is variable with the time, thus their value is not constant. Therefore, it is necessary to visualize the impedance change when a lightning hits overhead lines. This paper presents a model implemented using Transient Analysis of Control Systems (TACS)-MODELS to determine the impedance value considering their non-linear performance. Taking the impedance value equation and considering the current value, the FTR value is estimated during contingency simulation. The model considers a threshold current value for ground ionization phenomena initiation. Results show that the proposed model is effective, emulating with high precision the non-linear ground resistance behavior.
{"title":"Combined TACS-MODELS for Footing Tower Resistance considering ground ionization","authors":"J. Morales, E. Orduña, R. Cabral, A. Bretas","doi":"10.1109/NAPS.2014.6965471","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965471","url":null,"abstract":"Voltages produced by atmospheric discharges are considered the main causes of electric power outages. The study of atmospheric discharges should be analyzed and studied in order to make good insulator coordination. In this context, Footing Tower Resistance (FTR) is a crucial parameter in lightning strokes studies. FTR performance is variable with the time, thus their value is not constant. Therefore, it is necessary to visualize the impedance change when a lightning hits overhead lines. This paper presents a model implemented using Transient Analysis of Control Systems (TACS)-MODELS to determine the impedance value considering their non-linear performance. Taking the impedance value equation and considering the current value, the FTR value is estimated during contingency simulation. The model considers a threshold current value for ground ionization phenomena initiation. Results show that the proposed model is effective, emulating with high precision the non-linear ground resistance behavior.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127757072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965485
A. Reddy, Kerem Ekmen, V. Ajjarapu, U. Vaidya
Voltage stability plays major role in many blackout incidents. It has been recommended to develop online tools that can assess stability of the system and help in reducing the occurrence of large scale blackouts. This paper proposes a model free algorithm that can assess the short term voltage stability of the system in real time based on voltage measurements from PMU's. This approach uses simple calculations to determine the Lyapunov Exponent whose sign indicates the stability (negative) or instability (positive) of the system. This method is implemented in a real time cyber-physical test bed that is simulating the WECC 9 Bus system in RTDS that is interfaced with an SEL-421 PMU transmitting the voltage samples data over the Ethernet to OpenPDC which is interfaced to Matlab via a database. The setup is demonstrated and the algorithm is successful in detecting the stability of the system in real time.
{"title":"PMU based real-time short term voltage stability monitoring — Analysis and implementation on a real-time test bed","authors":"A. Reddy, Kerem Ekmen, V. Ajjarapu, U. Vaidya","doi":"10.1109/NAPS.2014.6965485","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965485","url":null,"abstract":"Voltage stability plays major role in many blackout incidents. It has been recommended to develop online tools that can assess stability of the system and help in reducing the occurrence of large scale blackouts. This paper proposes a model free algorithm that can assess the short term voltage stability of the system in real time based on voltage measurements from PMU's. This approach uses simple calculations to determine the Lyapunov Exponent whose sign indicates the stability (negative) or instability (positive) of the system. This method is implemented in a real time cyber-physical test bed that is simulating the WECC 9 Bus system in RTDS that is interfaced with an SEL-421 PMU transmitting the voltage samples data over the Ethernet to OpenPDC which is interfaced to Matlab via a database. The setup is demonstrated and the algorithm is successful in detecting the stability of the system in real time.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115849832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965455
A. Rahimi, A. Cloninger, M. Zarghami, M. Vaziri
This paper deals with the study of Volt-VAr control using Conservation Voltage Reduction (CVR) in distribution feeders penetrated at various levels of photovoltaic (PV) systems. For several decades, the practice of CVR has been implemented in utilities and the reports indicate that such practices have resulted in annual energy savings up to a few percentages, depending on factors such as the nature of the loads, climate, geographical area, etc. With more penetration of renewable sources of energy, such as photovoltaic systems, questions arise on how Volt-VAr control using CVR can be impacted and/or improved. Furthermore, it is desired to understand the behavior of aggregated loads at the main substation of the distribution system in order to estimate the effectiveness of CVR. As such, an actual distribution feeder has been simulated at various PV penetration levels, with and without implementation of CVR, and its CVR factor density has been calculated using aggregated load modeling based on ZIP parameters. Our results indicate that the increase in PV generation weakens the constant power component of the aggregated load, thus increasing the CVR factor density.
{"title":"Investigation on Volt-VAr control using CVR at various photovoltaic penetration levels","authors":"A. Rahimi, A. Cloninger, M. Zarghami, M. Vaziri","doi":"10.1109/NAPS.2014.6965455","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965455","url":null,"abstract":"This paper deals with the study of Volt-VAr control using Conservation Voltage Reduction (CVR) in distribution feeders penetrated at various levels of photovoltaic (PV) systems. For several decades, the practice of CVR has been implemented in utilities and the reports indicate that such practices have resulted in annual energy savings up to a few percentages, depending on factors such as the nature of the loads, climate, geographical area, etc. With more penetration of renewable sources of energy, such as photovoltaic systems, questions arise on how Volt-VAr control using CVR can be impacted and/or improved. Furthermore, it is desired to understand the behavior of aggregated loads at the main substation of the distribution system in order to estimate the effectiveness of CVR. As such, an actual distribution feeder has been simulated at various PV penetration levels, with and without implementation of CVR, and its CVR factor density has been calculated using aggregated load modeling based on ZIP parameters. Our results indicate that the increase in PV generation weakens the constant power component of the aggregated load, thus increasing the CVR factor density.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"20 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131958622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-24DOI: 10.1109/NAPS.2014.6965480
N. Srilatha, G. Yesuratnam
Secure operation of the power system in real time requires assessment of rapidly changing system conditions. Traditional security evaluation method involves running full load flow for each contingency, making it infeasible for real time application. This paper presents Radial Basis Function Neural Network (RBFNN) approach with feature selection for static security assessment and enhancement. The security of the system is assessed based on the intensity of contingencies. The necessary corrective control action to be taken in the event of insecure state is also proposed and the effect of this action has also been observed in order to enhance the security. RBFNN improves the response time compared to other neural networks. Feature selection of the input patterns is done to reduce the dimensionality to a large extent, maintaining the classification accuracy. This method is illustrated using New England 39 bus system.
{"title":"Security assessment and enhancement using RBFNN with feature selection","authors":"N. Srilatha, G. Yesuratnam","doi":"10.1109/NAPS.2014.6965480","DOIUrl":"https://doi.org/10.1109/NAPS.2014.6965480","url":null,"abstract":"Secure operation of the power system in real time requires assessment of rapidly changing system conditions. Traditional security evaluation method involves running full load flow for each contingency, making it infeasible for real time application. This paper presents Radial Basis Function Neural Network (RBFNN) approach with feature selection for static security assessment and enhancement. The security of the system is assessed based on the intensity of contingencies. The necessary corrective control action to be taken in the event of insecure state is also proposed and the effect of this action has also been observed in order to enhance the security. RBFNN improves the response time compared to other neural networks. Feature selection of the input patterns is done to reduce the dimensionality to a large extent, maintaining the classification accuracy. This method is illustrated using New England 39 bus system.","PeriodicalId":421766,"journal":{"name":"2014 North American Power Symposium (NAPS)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132544525","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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