Pub Date : 2009-05-17DOI: 10.1109/IPEMC.2009.5157850
Y. Wu, J. Zheng, T. Zheng
A novel control scheme for the active suspension in a 4-DOFs pantograph is presented here. The concepts of force cancellation, Skyhook damper and track-following spring are jointly applied to establish an active vibration control system. A force cancellation control scheme is used to isolate the sprung masses. Skyhook damper is employed to form the sprung mass. Track-following springs are applied for the sprung mass to follow the variable of contact line. For efficiency, the process for design of the active suspension parameters of pantograph using the constrained multiobjective evolutionary algorithm is employed to search for the parameters like damping ratio and spring constant to achieve an optimum, trade off peak of contact force, suspension displacement and inertia force. Computer simulations are performed using MATLAB to verify the proposed control scheme model.
{"title":"Optimizing active control scheme of high-speed pantograph","authors":"Y. Wu, J. Zheng, T. Zheng","doi":"10.1109/IPEMC.2009.5157850","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157850","url":null,"abstract":"A novel control scheme for the active suspension in a 4-DOFs pantograph is presented here. The concepts of force cancellation, Skyhook damper and track-following spring are jointly applied to establish an active vibration control system. A force cancellation control scheme is used to isolate the sprung masses. Skyhook damper is employed to form the sprung mass. Track-following springs are applied for the sprung mass to follow the variable of contact line. For efficiency, the process for design of the active suspension parameters of pantograph using the constrained multiobjective evolutionary algorithm is employed to search for the parameters like damping ratio and spring constant to achieve an optimum, trade off peak of contact force, suspension displacement and inertia force. Computer simulations are performed using MATLAB to verify the proposed control scheme model.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121964234","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157763
Suwon Lee, Jae-Hyung Kim, S. Lee, Byoung-Kuk Lee, C. Won
This paper presents a transformerless grid-connected photovoltaic (PV) system with active and reactive power control. The proposed system operations can be categorized into sunny mode and night mode. In night mode, it compensates for the reactive power demanded by nonlinear loads. In sunny mode, it not only supplies active power from the PV array to the grid or loads, but also performs power quality control (PQC), to improve the power factor and reduce the harmonic current. Simulation results are provided to demonstrate the effectiveness of the proposed system.
{"title":"A tranformerless grid-connected photovoltaic system with active and reactive power control","authors":"Suwon Lee, Jae-Hyung Kim, S. Lee, Byoung-Kuk Lee, C. Won","doi":"10.1109/IPEMC.2009.5157763","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157763","url":null,"abstract":"This paper presents a transformerless grid-connected photovoltaic (PV) system with active and reactive power control. The proposed system operations can be categorized into sunny mode and night mode. In night mode, it compensates for the reactive power demanded by nonlinear loads. In sunny mode, it not only supplies active power from the PV array to the grid or loads, but also performs power quality control (PQC), to improve the power factor and reduce the harmonic current. Simulation results are provided to demonstrate the effectiveness of the proposed system.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121990914","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157801
Qian Fang, Xueqin Wu, Jinjun Liu
In industrial application, the parallel active power filter (PAPF) is used most widely to eliminate the current distortion. It can be classified into two types according different current detection method. One is the load current detection type, and the other is the source current detection type. Load current detection method is an open-loop system, so both time delay and parameter deviation of the PAPF (especially in harmonic detector of PAPF) can cause incorrect compensation and unwanted remaining harmonics in the source current. Source current detection is a closed-loop system, while in traditional source current detection control method, system stability and performance of harmonic elimination is incompatible. In this paper a novel source current detection control of PAPF with selective harmonic compensation is proposed. Implementation of the proposed method in either synchronous or stationary frame is given in this paper. This method can ensure both the excellent performance of PAPF and the system stability. Moreover, this control method is insensitive to time delay and parameter deviation of the PAPF. Finally, simulation and experiment results are presented to demonstrate the conclusions.
{"title":"Novel source current detection control of active power filter with selective harmonic compensation","authors":"Qian Fang, Xueqin Wu, Jinjun Liu","doi":"10.1109/IPEMC.2009.5157801","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157801","url":null,"abstract":"In industrial application, the parallel active power filter (PAPF) is used most widely to eliminate the current distortion. It can be classified into two types according different current detection method. One is the load current detection type, and the other is the source current detection type. Load current detection method is an open-loop system, so both time delay and parameter deviation of the PAPF (especially in harmonic detector of PAPF) can cause incorrect compensation and unwanted remaining harmonics in the source current. Source current detection is a closed-loop system, while in traditional source current detection control method, system stability and performance of harmonic elimination is incompatible. In this paper a novel source current detection control of PAPF with selective harmonic compensation is proposed. Implementation of the proposed method in either synchronous or stationary frame is given in this paper. This method can ensure both the excellent performance of PAPF and the system stability. Moreover, this control method is insensitive to time delay and parameter deviation of the PAPF. Finally, simulation and experiment results are presented to demonstrate the conclusions.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122131404","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157814
Bo Wang, Dichen Liu, Li Xiong
GPS-based synchronous phasor measurement technology is a powerful tool for the security and reliable operation of the inter-connected electric power system. This paper presents an ACO-based approach to optimize the phasor measurement unit (PMU) placement problem. The pheromone trail persistence coefficient adaptive adjustment mechanism and stochastic perturbing progress are introduced into the Ant Colony System(ACS), in case the algorithm entering the stagnation behavior and getting stuck at local minima. The improved algorithm outperforms the ACS in obtaining global optimal solution and convergence speed, when applied to optimizing the PMU placement problem. A graph-theoretic procedure based on depth first search is adopted to analyze system observability. Simulation results in optimizing a provincial 46-bus system PMU placement problem show that the improved ACS algorithm is effective.
{"title":"Advance ACO system in optimizing power system PMU placement problem","authors":"Bo Wang, Dichen Liu, Li Xiong","doi":"10.1109/IPEMC.2009.5157814","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157814","url":null,"abstract":"GPS-based synchronous phasor measurement technology is a powerful tool for the security and reliable operation of the inter-connected electric power system. This paper presents an ACO-based approach to optimize the phasor measurement unit (PMU) placement problem. The pheromone trail persistence coefficient adaptive adjustment mechanism and stochastic perturbing progress are introduced into the Ant Colony System(ACS), in case the algorithm entering the stagnation behavior and getting stuck at local minima. The improved algorithm outperforms the ACS in obtaining global optimal solution and convergence speed, when applied to optimizing the PMU placement problem. A graph-theoretic procedure based on depth first search is adopted to analyze system observability. Simulation results in optimizing a provincial 46-bus system PMU placement problem show that the improved ACS algorithm is effective.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123955459","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157547
Y. Zhou, Priyesh Kumar, P. Bauer, J. Ferreira
A hybrid wind park concept which contains both constant speed wind turbine and variable speed wind turbine is proposed in this paper, as it can provide similar power quality and similar low voltage ride through capability with relatively low investment. The objective is to optimize the configuration of a hybrid wind park which has low levelised production cost, high power quality, high reliability and high low voltage ride through capability. This multi-criteria multi-objective optimization problem is solved by a design approach “Progressive Design Methodology”, which is divided into three stages. The final solution has the lowest levelised production cost with acceptable flicker level and LVRT capability.
{"title":"Optimization of a hybrid wind park through a design approach - Progressive Design Methodology","authors":"Y. Zhou, Priyesh Kumar, P. Bauer, J. Ferreira","doi":"10.1109/IPEMC.2009.5157547","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157547","url":null,"abstract":"A hybrid wind park concept which contains both constant speed wind turbine and variable speed wind turbine is proposed in this paper, as it can provide similar power quality and similar low voltage ride through capability with relatively low investment. The objective is to optimize the configuration of a hybrid wind park which has low levelised production cost, high power quality, high reliability and high low voltage ride through capability. This multi-criteria multi-objective optimization problem is solved by a design approach “Progressive Design Methodology”, which is divided into three stages. The final solution has the lowest levelised production cost with acceptable flicker level and LVRT capability.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124076422","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157626
N. Hoshi, Syoichi Nagata
Auxiliary resonant snubber inverters (RSIs) have been proposed a solution of demands for inverter, which are high efficiency and low EMI. In RSI, zero voltage switching (ZVS) on the inverter main switches is achieved by use of the auxiliary circuit; however, additional conduction loss increases simultaneously. The operating frequency of the auxiliary circuit in RSI can be reduced to a half of switching transition of a main switch when natural ZVS, in which ZVS can be achieved without using auxiliary circuit by using output current, is used. As a result, additional conduction loss can be suppressed. However, in this scheme, ZVS turn-on on main switch is failed near zero output current when dead-time was constant. As a solution for this problem, adjustable dead-time control scheme for RSI has been proposed; however, output current is distorted in low output power range. Thus, this paper proposes a dead-time compensation scheme for adjustable dead-time control. This paper shows the basic concept of the proposed compensation scheme. In addition, the effectiveness of the proposed scheme was verified through simulations using PSIM and experiments. As a result, it was verified that the proposed control scheme was able to improve THD without decreasing in efficiency.
{"title":"Dead-time compensation scheme for adjustable dead-time controlled resonant snubber inverter","authors":"N. Hoshi, Syoichi Nagata","doi":"10.1109/IPEMC.2009.5157626","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157626","url":null,"abstract":"Auxiliary resonant snubber inverters (RSIs) have been proposed a solution of demands for inverter, which are high efficiency and low EMI. In RSI, zero voltage switching (ZVS) on the inverter main switches is achieved by use of the auxiliary circuit; however, additional conduction loss increases simultaneously. The operating frequency of the auxiliary circuit in RSI can be reduced to a half of switching transition of a main switch when natural ZVS, in which ZVS can be achieved without using auxiliary circuit by using output current, is used. As a result, additional conduction loss can be suppressed. However, in this scheme, ZVS turn-on on main switch is failed near zero output current when dead-time was constant. As a solution for this problem, adjustable dead-time control scheme for RSI has been proposed; however, output current is distorted in low output power range. Thus, this paper proposes a dead-time compensation scheme for adjustable dead-time control. This paper shows the basic concept of the proposed compensation scheme. In addition, the effectiveness of the proposed scheme was verified through simulations using PSIM and experiments. As a result, it was verified that the proposed control scheme was able to improve THD without decreasing in efficiency.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124679275","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157670
J. Gao, Jianqiang Liu, F. Lin, T. Zheng
Predictive current controller is often adopted to compensate time delays caused by digital control. But traditional predictive current control algorithm for four-quadrant converters is an open-loop current observer essentially. Current value predicted is affected by many factors such as grid voltage extrapolation error, inductance error and dead-zone time. All of them will aggravate the grid current distortion. Current predictive algorithm based on repetitive control observer was proposed which has the advantages of simplicity and easy to be implemented on microprocessors in this paper. The proposed method can improve the predictive current precision and reduce the grid current distortion. The proposed method was verified by the experimental results.
{"title":"Improved predictive current controller for four-quadrant converters","authors":"J. Gao, Jianqiang Liu, F. Lin, T. Zheng","doi":"10.1109/IPEMC.2009.5157670","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157670","url":null,"abstract":"Predictive current controller is often adopted to compensate time delays caused by digital control. But traditional predictive current control algorithm for four-quadrant converters is an open-loop current observer essentially. Current value predicted is affected by many factors such as grid voltage extrapolation error, inductance error and dead-zone time. All of them will aggravate the grid current distortion. Current predictive algorithm based on repetitive control observer was proposed which has the advantages of simplicity and easy to be implemented on microprocessors in this paper. The proposed method can improve the predictive current precision and reduce the grid current distortion. The proposed method was verified by the experimental results.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129497849","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157646
Chunfang Wang, Zhaoan Wang, Qinchao Xu
Based on the small-signal model of the half-bridge circuit, the double close loops control system of the inverter arc welding power supply was designed under the average current control mode. For the control system's voltage and current controllers, the loop gains, angular frequencies of zeros and poles were determined. The simulation model of the designed double close loops control system was established in Matlab/Simulink. The simulations of the steady-state and dynamic characteristics under the conditions of open load to short circuit, load to short circuit and short circuit to load were given out in large-signal. The parameters of the main circuit and control system were optimized according to simulation results. Finally, experiments were carried out and experimental waveforms were obtained. The experimental and simulation results were corresponded well and the rationality of the studying method was verified, a designing method to the inverter arc welding power supply was put forward.
{"title":"Study on dynamic characteristics of inverter arc welding power supply based on double-loop control","authors":"Chunfang Wang, Zhaoan Wang, Qinchao Xu","doi":"10.1109/IPEMC.2009.5157646","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157646","url":null,"abstract":"Based on the small-signal model of the half-bridge circuit, the double close loops control system of the inverter arc welding power supply was designed under the average current control mode. For the control system's voltage and current controllers, the loop gains, angular frequencies of zeros and poles were determined. The simulation model of the designed double close loops control system was established in Matlab/Simulink. The simulations of the steady-state and dynamic characteristics under the conditions of open load to short circuit, load to short circuit and short circuit to load were given out in large-signal. The parameters of the main circuit and control system were optimized according to simulation results. Finally, experiments were carried out and experimental waveforms were obtained. The experimental and simulation results were corresponded well and the rationality of the studying method was verified, a designing method to the inverter arc welding power supply was put forward.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129684291","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157791
Lian Dibo, Feng Xiaoyun, Liu Shuichang, Gu Bochuan
This paper presents a dynamical control of fuel cell and battery hybrid system to supply a frequently changing load. In this paper, a hybrid system is built in order to solve a big problem that the voltage will drop when PEM fuel cell current increases: the fuel cell is used to supply the rated power to the load, a Lithium battery will supply peak power that the load demands, meanwhile, the fuel cell will charge the battery when the battery voltage is low during the light load condition. A DC/DC converter is to maintain the overall voltage to constant and serve the load properly. In this system, the main control theory is as follows: (1) when the fuel cell can afford the load, only fuel cell will power the load through DC/DC, and charge the battery if necessary; (2) when the load goes exceeding fuel cell's power range, the battery will help to power the load automatically.
{"title":"PEM fuel cell and battery hybrid system studied in Matlab/Simulink","authors":"Lian Dibo, Feng Xiaoyun, Liu Shuichang, Gu Bochuan","doi":"10.1109/IPEMC.2009.5157791","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157791","url":null,"abstract":"This paper presents a dynamical control of fuel cell and battery hybrid system to supply a frequently changing load. In this paper, a hybrid system is built in order to solve a big problem that the voltage will drop when PEM fuel cell current increases: the fuel cell is used to supply the rated power to the load, a Lithium battery will supply peak power that the load demands, meanwhile, the fuel cell will charge the battery when the battery voltage is low during the light load condition. A DC/DC converter is to maintain the overall voltage to constant and serve the load properly. In this system, the main control theory is as follows: (1) when the fuel cell can afford the load, only fuel cell will power the load through DC/DC, and charge the battery if necessary; (2) when the load goes exceeding fuel cell's power range, the battery will help to power the load automatically.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129711270","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 : 2009-05-17DOI: 10.1109/IPEMC.2009.5157793
Lu Xueqin, Huang Fuzhen, Liu Gang, Qiu Rongfu
Fuel cell vehicles have a high potential to reduce both energy consumption and carbon dioxide emissions. Hydrogen storage is the key technology towards the hydrogen society. However, the low density limits the amount of hydrogen stored on board and also prevents wide penetration of fuel cells. This paper provides an up-to-date review of fuel cell technology and application. A description of fuel cell operating principles is followed by a comparative analysis of the current fuel cell technology. Appropriate applications for current and perceived potential advances of fuel cell technology are discussed, and the latest system development is described.
{"title":"The challenges of technologies for fuel cell and its application on vehicles","authors":"Lu Xueqin, Huang Fuzhen, Liu Gang, Qiu Rongfu","doi":"10.1109/IPEMC.2009.5157793","DOIUrl":"https://doi.org/10.1109/IPEMC.2009.5157793","url":null,"abstract":"Fuel cell vehicles have a high potential to reduce both energy consumption and carbon dioxide emissions. Hydrogen storage is the key technology towards the hydrogen society. However, the low density limits the amount of hydrogen stored on board and also prevents wide penetration of fuel cells. This paper provides an up-to-date review of fuel cell technology and application. A description of fuel cell operating principles is followed by a comparative analysis of the current fuel cell technology. Appropriate applications for current and perceived potential advances of fuel cell technology are discussed, and the latest system development is described.","PeriodicalId":375971,"journal":{"name":"2009 IEEE 6th International Power Electronics and Motion Control Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129726857","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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