Supercapacitor-based energy storage device with direct connection to power line

点击翻译按钮获取中文摘要

This proposal addresses the problem of energy storage in the context of railway applications, where one would like to store the kinetic energy of train wagons instead of dissipating it as heat upon braking. This stored energy can then be re-used afterwards to restart the train, so the round-trip efficiency of start/stop operations can be drastically improved. The technology of supercapacitors is currently the only one that can withstand the large amount of power involved in braking/starting operations of a train. However, the classical use of supercapacitors involves lossy and/or complex voltage balancing circuits, as well as a costly power converter as the interface with the power network. Herein, we propose an innovative way to circumvent most of the classical problems with supercapacitor energy storage, consisting of adding one or two power electronic switches to each energy storage elementary cell. This allows controlling the voltage of each supercapacitor on an individual basis and at the same time, it turns the supercapacitor assembly into a intrinsic power converter, reducing substantially the cost of the overall system. At the end of this project, we will realize a full scale proof-of-concept in terms of operating currents encountered in the railway industry (200-400 Amperes). This will not only show that the technology works, but also that its intrinsic modularity provides substantial benefits in terms of reliability and maintenance, which directly translates in reduction of operational costs. The applicants have filed a PCT patent application on their invention, in collaboration with Gestion Univalor L.P., the commercialization partner of École Polytechnique, who will assist in eventual commercial licensing of this new technology. The technology has already been discussed with a number of major players in the railway industry.