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Showing 1 to 20 of 24 for “"Ultracapacitors"”.
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Hybrid electric vehicle regenerative-braking using ultracapacitors
The concept and application of ultracapacitors for electric load leveling and regenerative braking is presented. Proposed sizing of an ultracapacitor system is presented and discussed based on the available energy and the nominal operating voltage from a hybrid electric vehicle transit bus; A …
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Ultracapacitors for off grid wind power systems
… ways to resolve this problem by developing "ultracapacitors" that store energy by assembling ions at the surface of a porous material. That is why ultracapacitors coupled with the energy storage battery could present a challenge to the electrical power grid. Such a design allows …
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Modeling of electrical behavior of graphene-based ultracapacitors
… energy storage, especially for high performance ultracapacitors. Graphene-based ultracapacitors show high stability, significantly-improved capacitance and energy density with fast charging and discharging time at a high current density, due to enhanced ionic electrolyte accessibility in deeper …
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Technology assessment and market analysis of solid state ultracapacitors
… provides quantitative analysis of Solid State Ultracapacitors (SSUs) from technological and financial perspectives. SSUs are Ultracapacitors with solid electrolytes predicted to have huge application potential as the electrical energy storage device in Hybrid Electrical Vehicles (HEVs) due to …
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Advances in Lithium Ion Batteries Obviate Need for Ultracapacitors in Electric Vehicles
<p>Battery technologies are rapidly obviating the need for battery/ultracapacitor (UC) hybrid circuit topologies (active/passive) in electric vehicles (EV). In this paper, available models in MATLAB/Simulink are used to assess the need for lithium ion battery/ultracapacitor hybrid topologies. The …
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The assessment of battery-ultracapacitor hybrid energy storage systems
Battery-ultracapacitors hybrid energy storage systems (ESS) could combine the high power density and high life cycle of ultracapacitors with the high energy density of batteries, which forms a promising energy storage system. In this thesis, an assessment of the benefits of the hybrid ESS relative …
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High energy and power density nanotube-enhanced ultracapacitor design, modeling, testing, and predicted performance
… (limited to tens of minutes). Commercial ultracapacitors are energy storage systems that solve these problems by offering more than one million recharges with little capacitance degradation, recharge times on the order of few seconds, and unlimited shelf life. However, today's …
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Design of a miniature high-speed carbon-nanotube-enhanced ultracapacitor for electronics applications
… are utilized to create miniature high-speed ultracapacitors. Because the nanotubes are grown on silicon using low pressure chemical vapor deposition, this technique also opens the possibility of high-value integrated (on-die) capacitors. Using this technique a capacitance density of 52 …
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A simulation-based assessment of plug-in hybrid electric vehicle architectures
… PHEVs, as well as parallel and split PHEVs with ultracapacitors, were performed in Autonomie, the vehicle simulation package released by Argonne National Laboratory as the successor to the Powertrain System Analysis Toolkit (PSAT). The PHEV configurations were parameterized by battery capacity, …
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Improvements on carbon nanotube structures in high-energy density ultracapacitor electrode design
Ultracapacitors are a class of electrochemical energy storage device that is gaining significant industrial traction due to their high charging rate and cycle life compared to rechargeable batteries; however, they store significantly less energy on a per-volume basis. The quest to find an electrode …
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Memory and data communication link architecture for micro-implants
… to replace the bulky batteries in these devices. Ultracapacitors have the potential to be integrated on a silicon wafer, and have the benefits of an unlimited number of recharge cycles and extremely rapid recharging times. However, they present an essential challenge in that the voltage drops …
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Energy management techniques for ultra-small bio-medical implants
… solve the engineering challenges posed by using ultracapacitors for energy storage. A major problem with using any capacitor as an energy source is the fact that its voltage drops rapidly with decreasing charge. This leaves the circuit to cope with a large supply variation and can lead to energy …
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Increasing carbon nanotube forest density
… electrode in electrochemical double layer (EDLC) ultracapacitors with vertically aligned CNT forests (VACNTs). The specific capacitance of an EDLC scales with the specific surface area of the electrodes, thus this research seeks to increase the areal density of VACNTs, as areal density also scales …
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Design considerations and characterization of Origami [TM] electrochemical capacitors
… capacitors, also known as supercapacitors, ultracapacitors, and electric double-layer capacitors, have recently received attention as electrical energy storage devices. The devices are both high power and high energy, making them ideally suited for load balancing applications in such …
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Ultracapacitor characterization using a novel dynamic parameter identification modeling technique for electric transportation applications
Ultracapacitors (UCs), also known as Supercapacitors or double layer capacitors, are the promising technology devices used for storing energy in the field of energy storage systems. These ultra-capacitors, being a low voltage device, provide fairly large capacitance values as compared to the …
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Modeling, control, and design of hybrid electrical and thermal energy storage systems
… includes energy-dense batteries and power-dense ultracapacitors for electrical energy storage, and PCM thermal energy storage modules and coolant loops for thermal energy storage. Multi-domain graph-based modeling techniques are used to facilitate modeling, control, and design optimization of the …
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Communication and energy delivery architectures for personal medical devices
… unlimited number of re-charge cycles offered by ultracapacitors. To ease patient usability, a rapid wireless capacitor charging architecture is proposed that employs a multi-tapped secondary inductive coil to provide charging times that are significantly faster than conventional approaches.
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Benefits of battery-uItracapacitor hybrid energy storage systems
… created to accurately represent the battery and ultracapacitors. These models are used in simulations of the same test cases from the physical experiments, and efficiency gains are compared. The circuit models differed from the experimentation by less than 1%. Both experimental and simulated data …
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Synthesis Of Graphene Nanomaterials And Their Application In Electrochemical Energy Storage
… several decades. Supercapacitors, also known as ultracapacitors, or electrochemical capacitors, with fast power delivery and long cycle life are complementing or even replacing batteries in many applications. The rapid development of miniaturized electronic devices has led to a growing need for …
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A design framework for reconfigurable controllers with emphasis on electric drive wheels
… and proposes further research in the area of ultracapacitors. It is also recommended to look into upcoming technologies like SiC and GaN switches. However, work still needs to be done to make the controllers cost effective, which can be done by making a standard set of reconfigurable motor …
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