Maxwell ultracapacitor used in recuperation system

A Maxwell Technologies product story

Edited by the Electronicstalk editorial team Dec 16, 2008

The Korean Railroad Research Institute (KRRI) is overseeing installation of an ultracapacitor-based braking energy recuperation system in a subway station to understand the system's benefits.

David Schramm, Maxwell's president and chief executive officer, said that Woojin Industrial Systems, KRRI's contractor for the project, selected Maxwell's 48V Boostcap ultracapacitor modules as the recuperation system's energy storage element.

Earlier this year, Woojin took delivery of 72 modules and completed installation of a 750V DC system for testing and evaluation on the Gyengsan light rail transit track.

Maxwell delivered another 220 modules to Woojin in October for a 1500V DC system that will be installed during the second quarter of 2009, with system demonstrations set to follow.

In the Gyengsan light rail installation, preliminary testing conducted by KRRI and Woojin during system development projected that the recuperation system would reduce grid power consumption by more than 20 per cent.

If this is matched in actual operation it could save enough energy to recoup the initial investment in less than four years.

Boostcap ultracapacitor products deliver up to 10 times the power and longevity of batteries, require no maintenance and operate reliably in extreme temperatures.

In transportation applications, they recapture energy from braking for reuse in hybrid and all-electric drive trains, reducing energy consumption and emissions.

They also provide compact and lightweight solutions to stabilise automotive power networks and power new all-electric subsystems, such as drive-by-wire steering.

In mission-critical industrial applications, where back-up power ensures continued operation or a soft shutdown in the event of power interruptions, ultracapacitors provide reliable energy storage.

In wind turbine blade pitch and braking systems and other industrial applications, they provide a reliable solid-state solution to buffer short-term mismatches between the power available and the power required.