The power/energy losses reduction in distribution systems is an important issue during planning and operation, with important technical and economical implications. Thus, the energy losses minimization implies not onl...The power/energy losses reduction in distribution systems is an important issue during planning and operation, with important technical and economical implications. Thus, the energy losses minimization implies not only the technical improvement of the network, through its renewal with the introduction of the technological innovations in the equipment and circuit components as well as the optimal planning of the design and development of the network, but also requires the use of the methods and software tools to facilitate the operation process. The paper presents a strategy for power / energy saving which is replacement of the 6 kV voltage level with 20 kV voltage level. In this line, different urban distribution networks were analyzed using fuzzy techniques for load modeling.展开更多
This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only...This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.展开更多
To satisfy the requirements for various electric systems and energy storage devices with both high energy density and power density as well as long lifespan, sodium-ion capacitors(SICs) consisting of battery anode and...To satisfy the requirements for various electric systems and energy storage devices with both high energy density and power density as well as long lifespan, sodium-ion capacitors(SICs) consisting of battery anode and supercapacitor cathode, have attracted much attention due to the abundant resources and low cost of sodium source. SICs bridge the gap between the batteries and the supercapacitors,which can be used as competitive candidates for large-scale energy storage. In this review, the battery-type anode materials and the capacitor-type cathode materials are classified and introduced in detail. The advantages of various electrolytes including organic electrolytes, aqueous electrolytes and ion liquid electrolytes are also discussed sequentially. In addition, from the perspective of practical value, the presentations of the SICs at the current situation and the potential application in urban rail are displayed. Finally, the challenge,future research and prospects towards the SICs are put forward.展开更多
文摘The power/energy losses reduction in distribution systems is an important issue during planning and operation, with important technical and economical implications. Thus, the energy losses minimization implies not only the technical improvement of the network, through its renewal with the introduction of the technological innovations in the equipment and circuit components as well as the optimal planning of the design and development of the network, but also requires the use of the methods and software tools to facilitate the operation process. The paper presents a strategy for power / energy saving which is replacement of the 6 kV voltage level with 20 kV voltage level. In this line, different urban distribution networks were analyzed using fuzzy techniques for load modeling.
文摘This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.
基金financially supported by the National Natural Science Foundation of China (51672308, 51972025 and 61888102)
文摘To satisfy the requirements for various electric systems and energy storage devices with both high energy density and power density as well as long lifespan, sodium-ion capacitors(SICs) consisting of battery anode and supercapacitor cathode, have attracted much attention due to the abundant resources and low cost of sodium source. SICs bridge the gap between the batteries and the supercapacitors,which can be used as competitive candidates for large-scale energy storage. In this review, the battery-type anode materials and the capacitor-type cathode materials are classified and introduced in detail. The advantages of various electrolytes including organic electrolytes, aqueous electrolytes and ion liquid electrolytes are also discussed sequentially. In addition, from the perspective of practical value, the presentations of the SICs at the current situation and the potential application in urban rail are displayed. Finally, the challenge,future research and prospects towards the SICs are put forward.