The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focu...The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focuses on the importance of implementing minimum efficiency standards in Brazil and elsewhere and presents the state of the art in domestic and international legislation and standards pertaining to induction motors. It also covers advancements in motor technology, by means of an analysis of motors currently on the market, and trends in said technology, with particular emphasis on the search for new materials for permanent magnet manufacturing. The results of experimental testing of a permanent-magnet motor and a premium-efficiency induction motor are presented and discussed, with the objective of contributing to definition of the IE4 （Efficiency Level from International Electrotechnical Commission） standard and to the goal-oriented Brazilian efficiency program. The present article described the results of experimental testing with an induction motor and a line-start permanent-magnet motor and concluded that permanent-magnet motors are superior in performance to induction motors at loads between half and full, with an efficiency advantage of up to 6.7%. However, in applications with wide variations in load, with motor operation below half load, use of permanent-magnet motors is not economically feasible, as the current cost of these motors exceeds that of induction motors. Another relevant finding concerns the current harmonic distortion observed during testing. The tested permanent-magnet motor exhibited a distortion of up to 13.5%, exceeding Institute of Electrical and Electronics Engineers Standard 519/1992 recommended limits. This behavior must be clearly specified and taken into account by future standards that define the super premium class, lest the impact of harmonic distortion prove to be detrimental to industries that adopt these motors for their processes.展开更多
In this article, the replacement of the car battery by a hybrid supply is proposed. The specific power of the supercapacitor makes it very attractive for the startup of the car. This component has very high lifetime ...In this article, the replacement of the car battery by a hybrid supply is proposed. The specific power of the supercapacitor makes it very attractive for the startup of the car. This component has very high lifetime （1 million of cycles） which can improve the lifetime of the supply （for starter or starter-alternator）. After the identification of the internal combustion engine torque developed at the startup, the validation of the hybrid supply interest is proved by the simulation of the system using Matlab-Simulink software. Finally, a test bench is developed in the laboratory to validate the simulation results.展开更多
Novel carbon-carbon ultracapacitors and hybrid lithium-carbon devices are described. New approach to the design of electrode materials and electrochemical systems followed by the improved design of ultracapacitor cell...Novel carbon-carbon ultracapacitors and hybrid lithium-carbon devices are described. New approach to the design of electrode materials and electrochemical systems followed by the improved design of ultracapacitor cells and modules have resulted in prototypes of superior performance that was verified by independent tests in the Institute of Transportation Studies, UC （ultracapacitor） Davis, in JME Inc., in Wayne State University, and in some other labs. All the test results confirm the superlative performance of the devices developed： carbon-carbon ultracapacitors demonstrate the extremely low inner resistance resulting in the highest power capability and efficiency that also alleviates the cooling requirements and improves safety. Our ＂parallel＂ hybrid devices demonstrate substantially higher energy density than competing LIC （lithium ion capacitor） technologies keeping at the same time the high power density, comparable with the best carbon-carbon ultracapacitors available in the market. In order to make ultracapacitor technology even more attractive to automakers, new organic electrolytes （not ionic liquids） have been developed and are currently under testing at temperatures about 100 ℃ and voltages up to 3.0 V.展开更多
The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspe...The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspects of such combination efforts were considered for evaluating the four types of hybrid energy-storage system(HESS)topologies.First,a novel optimization framework was proposed and implemented to optimize the voltage level of a battery pack and an ultracapacitor pack for the four types of HESS topologies.During the optimization process,the dynamic programming(DP)algorithm was iteratively applied to determine the optimal control actions.The simulation results with DP were used to evaluate the energy efficiency of different HESS topologies at different voltage levels.Second,the optimized voltage level of the battery and ultracapacitor in each topology indicates that a higher voltage level usually results in a better system performance.The simulation results also illustrate that the optimized rated voltage level of the battery pack is approximately 499.5 V,while for the ultracapacitor pack,the optimized voltage level is at its maximum allowed value.Note that the constraint of the battery voltage is initialized at200–600 V.Third,the control rules for different HESS topologies were obtained through the systematic analysis of the simulation results.In addition,advantages and disadvantages of the four topologies were summarized through evaluation of the efficiency and operating currents of the batteries and the ultracapacitor.展开更多
文摘The year 2012 marked the 10th anniversary of publication of Presidential Decree No. 4508/2002, which set forth minimum efficiency standards for induction motors in Brazil. Within this context, the present article focuses on the importance of implementing minimum efficiency standards in Brazil and elsewhere and presents the state of the art in domestic and international legislation and standards pertaining to induction motors. It also covers advancements in motor technology, by means of an analysis of motors currently on the market, and trends in said technology, with particular emphasis on the search for new materials for permanent magnet manufacturing. The results of experimental testing of a permanent-magnet motor and a premium-efficiency induction motor are presented and discussed, with the objective of contributing to definition of the IE4 （Efficiency Level from International Electrotechnical Commission） standard and to the goal-oriented Brazilian efficiency program. The present article described the results of experimental testing with an induction motor and a line-start permanent-magnet motor and concluded that permanent-magnet motors are superior in performance to induction motors at loads between half and full, with an efficiency advantage of up to 6.7%. However, in applications with wide variations in load, with motor operation below half load, use of permanent-magnet motors is not economically feasible, as the current cost of these motors exceeds that of induction motors. Another relevant finding concerns the current harmonic distortion observed during testing. The tested permanent-magnet motor exhibited a distortion of up to 13.5%, exceeding Institute of Electrical and Electronics Engineers Standard 519/1992 recommended limits. This behavior must be clearly specified and taken into account by future standards that define the super premium class, lest the impact of harmonic distortion prove to be detrimental to industries that adopt these motors for their processes.
文摘In this article, the replacement of the car battery by a hybrid supply is proposed. The specific power of the supercapacitor makes it very attractive for the startup of the car. This component has very high lifetime （1 million of cycles） which can improve the lifetime of the supply （for starter or starter-alternator）. After the identification of the internal combustion engine torque developed at the startup, the validation of the hybrid supply interest is proved by the simulation of the system using Matlab-Simulink software. Finally, a test bench is developed in the laboratory to validate the simulation results.
文摘Novel carbon-carbon ultracapacitors and hybrid lithium-carbon devices are described. New approach to the design of electrode materials and electrochemical systems followed by the improved design of ultracapacitor cells and modules have resulted in prototypes of superior performance that was verified by independent tests in the Institute of Transportation Studies, UC （ultracapacitor） Davis, in JME Inc., in Wayne State University, and in some other labs. All the test results confirm the superlative performance of the devices developed： carbon-carbon ultracapacitors demonstrate the extremely low inner resistance resulting in the highest power capability and efficiency that also alleviates the cooling requirements and improves safety. Our ＂parallel＂ hybrid devices demonstrate substantially higher energy density than competing LIC （lithium ion capacitor） technologies keeping at the same time the high power density, comparable with the best carbon-carbon ultracapacitors available in the market. In order to make ultracapacitor technology even more attractive to automakers, new organic electrolytes （not ionic liquids） have been developed and are currently under testing at temperatures about 100 ℃ and voltages up to 3.0 V.
基金supported by the Beijing Institute of Technology Research Fund Program for Young Scholarsthe Excellent Young Scholars Research Fund of Beijing Institute of Technologythe National Science & Technology Pillar Program(Grant No.2013BAG05B00)
文摘The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspects of such combination efforts were considered for evaluating the four types of hybrid energy-storage system(HESS)topologies.First,a novel optimization framework was proposed and implemented to optimize the voltage level of a battery pack and an ultracapacitor pack for the four types of HESS topologies.During the optimization process,the dynamic programming(DP)algorithm was iteratively applied to determine the optimal control actions.The simulation results with DP were used to evaluate the energy efficiency of different HESS topologies at different voltage levels.Second,the optimized voltage level of the battery and ultracapacitor in each topology indicates that a higher voltage level usually results in a better system performance.The simulation results also illustrate that the optimized rated voltage level of the battery pack is approximately 499.5 V,while for the ultracapacitor pack,the optimized voltage level is at its maximum allowed value.Note that the constraint of the battery voltage is initialized at200–600 V.Third,the control rules for different HESS topologies were obtained through the systematic analysis of the simulation results.In addition,advantages and disadvantages of the four topologies were summarized through evaluation of the efficiency and operating currents of the batteries and the ultracapacitor.
