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The railway station as link of electromobilty

KEYNOTE

• Power range: for systems of up to 100MWh

• Power range: 1kW-30MW
• Loading and unloading times: hours

• Number of charge and discharge cycles: 1,000-3,000
• Performance: 75-99 according to technologies
• Self discharge rate: 0 - 20 per month according to technologies
• High for Li-ion and NI-CD tools Pb-acid-low prices

• As type may have toxic elements

2.4.3 Supercapacitors

The double layer supercapacitors are electrochemical capacitors with a density of unusually
high energy compared to conventional capacitors, typically thousands of times greater than a
high capacity electrolytic capacitor. They are storage devices of power with one capacitance
greater than a farad, reaching up to thousands of farads. These devices have a maximum of up
to 30 WhKg energy density.
The accumulation of energy relies on the confinement of electrostatic charges on small devices,
formed by pairs of conductive plates separated by a dielectric medium. The construction and
operation is similar to a conventional capacitor on a large scale. The supercapacitors are
characterized by being able to be loaded and unloaded in the times on the order of seconds,
which makes them especially suited to respond to needs of power tips or short duration power
outages. This is because the storage of loads is purely electrostatic.
ADVANTAGES: Because of the speed of loading and unloading, can provide high chargedischarge
currents, which instead damages to the batteries. They have a number of cycles of life of millions
of times and require no maintenance. They can work in extreme temperature conditions. On
the other hand, do not have toxic elements composition, very common in batteries.
DISADVANTAGES: limited capacity to store energy and day of today, its higher price.
The main characteristics of these devices are listed below:

• High capacities: 1-5,000 F
• Energy density: 1-10 WhKg
• Power density: kWKg 1-10

• Loading and unloading times: minutes, seconds
• Number of charge and discharge cycles: 10e6
• Limited operating voltage: 500V-1

• Electrical performance: 95-99
• Very low discharging
• Relatively high price

• Do not need maintenance
• Do not have toxic elements
• Resistance to adverse conditions of temperature

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 303