A 2 MW Flywheel for Hybrid Locomotive Power

The University of Texas at Austin Center for Electromechanics (UT-CEM) is currently developing an Advanced Locomotive Propulsion System (ALPS) as part of the Next Generation High-Speed Rail program sponsored by the Federal Railroad Administration (FRA). The ALPS consists of a gas turbine and synchronous alternator, combined with an induction motor coupled flywheel energy storage system (FESS). The prime power and FESS are coupled through a DC power link, as is the conventional AC traction drive system. The energy system includes auxiliary support systems to provide thermal management, bearing systems, controls, and power conversions. The energy exchange capacity of the flywheel is 360 MJ (100 kWhr). This paper presents the requirements, considerations, and design of the integrated turbine and flywheel power system. Significant development efforts have gone into the high-speed synchronous alternator, the flywheel power converter, the highspeed induction machine for the flywheel, the flywheel itself and its magnetic bearings. The fabrication status of these components and testing progress is also reported.