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Electrochemical Supercapacitors for Energy Storage and Delivery
these hybrids is achievable. A sawtooth control strategy implemented in testing was also used in two modes: charge-depleting inherently-efficient electric
mode (engine off), and recharging high-power engine mode. Furthermore,
regenerative braking was implemented for supercapacitor recharging.
The micro-hybrid electric vehicles are the simplest versions that improve
fuel efficiency. Burke et al. [2] used a small electric motor and a module of
18 commercial carbon–carbon double-layer-based ESs. They demonstrated a
40% improvement in fuel economy with the Federal Urban Driving Schedule
(FUDS) and an increase in engine efficiency of 30% in comparison to an ICE
of 19%.
Charge-sustaining hybrid vehicles that are more reliant on high-power,
high-energy-density HESS devices, used an 80 cell module to power a 35
kW electric motor. The result was a slight improvement to FUDS fuel economy (~45%). However, the change is not significant relative to micro-hybrids.
Finally, a hybrid plug-in with a power of 70 kW (45 kW provided by the supercapacitor module) yielded a similar improvement to fuel economy through
simulation.
Hybrid carbon ESs (Chapter 2) with larger energy densities of 8 to 12 Wh/kg
were used in simulation testing for comparison. An unbalanced increase in
power density (i.e., less than double) and reduced power efficiency impacted
their suitability for micro-hybrids that rely on high-efficiency power. Chargesustaining and plug-in hybrids appear to be more suitable applications.
The use of ES in HESS has thus far demonstrated dependability for powerreliant vehicle operations. Successful integration of ESs to improve fuel efficiency of hybrid buses and micro-hybrid passenger vehicles also suggests
further benefits for their assimilation into hybrid transport applications.
6.4 Supercapacitor Integration with Batteries
Batteries and ESs possess complementary characteristics that lean toward
a highly synergistic hybridization of these two energy storage systems.
Generally the overlapping of a battery’s high energy density with an ES’s high
power density produces a straightforward benefit over either individual system by taking advantage of each characteristic. The resulting performance is
in actual fact highly related to the interconnections and controls implemented
in the system to exploit their strengths and avoid their weaknesses. The power
flow coordination and control management for improved energy efficiency is
critical for any design, and must be weighed for a desired application in terms
of computational and economic costs. An overview of solutions proposed for
integration is provided for consideration in performance and system design.
Electrochemical Supercapacitors for Energy Storage and Delivery
these hybrids is achievable. A sawtooth control strategy implemented in testing was also used in two modes: charge-depleting inherently-efficient electric
mode (engine off), and recharging high-power engine mode. Furthermore,
regenerative braking was implemented for supercapacitor recharging.
The micro-hybrid electric vehicles are the simplest versions that improve
fuel efficiency. Burke et al. [2] used a small electric motor and a module of
18 commercial carbon–carbon double-layer-based ESs. They demonstrated a
40% improvement in fuel economy with the Federal Urban Driving Schedule
(FUDS) and an increase in engine efficiency of 30% in comparison to an ICE
of 19%.
Charge-sustaining hybrid vehicles that are more reliant on high-power,
high-energy-density HESS devices, used an 80 cell module to power a 35
kW electric motor. The result was a slight improvement to FUDS fuel economy (~45%). However, the change is not significant relative to micro-hybrids.
Finally, a hybrid plug-in with a power of 70 kW (45 kW provided by the supercapacitor module) yielded a similar improvement to fuel economy through
simulation.
Hybrid carbon ESs (Chapter 2) with larger energy densities of 8 to 12 Wh/kg
were used in simulation testing for comparison. An unbalanced increase in
power density (i.e., less than double) and reduced power efficiency impacted
their suitability for micro-hybrids that rely on high-efficiency power. Chargesustaining and plug-in hybrids appear to be more suitable applications.
The use of ES in HESS has thus far demonstrated dependability for powerreliant vehicle operations. Successful integration of ESs to improve fuel efficiency of hybrid buses and micro-hybrid passenger vehicles also suggests
further benefits for their assimilation into hybrid transport applications.
6.4 Supercapacitor Integration with Batteries
Batteries and ESs possess complementary characteristics that lean toward
a highly synergistic hybridization of these two energy storage systems.
Generally the overlapping of a battery’s high energy density with an ES’s high
power density produces a straightforward benefit over either individual system by taking advantage of each characteristic. The resulting performance is
in actual fact highly related to the interconnections and controls implemented
in the system to exploit their strengths and avoid their weaknesses. The power
flow coordination and control management for improved energy efficiency is
critical for any design, and must be weighed for a desired application in terms
of computational and economic costs. An overview of solutions proposed for
integration is provided for consideration in performance and system design.