A FLYWHEEL VARIATOR ENERGY-STORAGE SYSTEM

Flywheels are proving to be an ideal form of energy storage on account of their high power density, cycle life and storage efficiency. This paper describes an energy storage system comprised of a steel flywheel and mechanical variator, designed to provide the main drive power for a hybrid railcar which can be charged either rapidly at stops on the route, or continuously at a constant rate from an on-board primary low power source. By operation on rails at urban speeds, with brake energ y recovery, energy losses and consumption are minimised. A further app lication of the system is in load matching in autonomous wind diesel s ystems, as a means of load levelling and absorbing fluctuations in win d power. The results of laboratory tests on the energy storage unit ar e presented, along with the analysis of performance tests on a hybrid flywheel-battery rail vehicle. (C) 1996 Elsevier Science Ltd.