The need for increased design flexibility and reduced weight and volume for electric power generation infrastructure has driven an increased interest in the use of high speed generators directly driven by gas turbine prime movers for both military and commercial power generation applications. This transition has been facilitated by the use of dc distribution and recent advances in the performance of solid state power conversion equipment, enabling designers to decouple the power generation frequency from typical 60 Hz ac loads. Operation of the generator at the turbine output speed eliminates the need for a speed reduction gearbox and can significantly increase the volumetric and gravimetric power density of the power generation system. This is particularly true for turbines in the 3 to 10 MW power range which typically operate with power turbine speeds of 7,000 to 16,000 rpm. The University of Texas at Austin, Center for Electromechanics (UT-CEM) is currently developing a 3 MW high speed generator and turbine drive system for a hybrid vehicle propulsion system as a part of the Federal Railroad Administration’s Advanced Locomotive Propulsion System (ALPS) Program. The ALPS system consists of a 3 MW turbine/alternator prime mover coupled with a 480 MJ, 2 MW flywheel energy storage system. Although designed as the prime mover for a high speed passenger locomotive, the compact turbine/alternator package is well suited for use in marine applications as an auxiliary turbine generator set or as the primary propulsion system for smaller vessels. The ALPS 3 MW high speed generator and turbine drive system were originally presented at the ASME Turbo Expo 2005 [1]. This follow-on paper presents the results of mechanical spin testing and No-Load electrical testing of the high speed generator and the Static Load testing of the generator and turbine drive system at NAVSEA (Philadelphia, PA) with a fixed resistive load. The generator has been tested to a 1.5 MW power level in the Static Load procedures and is being prepared for the final test phase to include dynamic power exchange with the flywheel.

The University of Texas at Austin Center for Electromechanics (UT-CEM) is currently engaged in the development of an Advanced Locomotive Propulsion System (ALPS) for high speed passenger rail locomotives. The project is sponsored by the Federal Railroad Administration as part of the Next Generation High Speed Rail program. The goal of the ALPS project is to demonstrate the feasibility of an advanced locomotive propulsion system with the following features: • Operation up to 150 mph on existing infrastructure; • Acceleration comparable to electric locomotives; • Elimination of $3–5M per mile electrification costs; • Fuel efficient operation with low noise and exhaust emissions. The propulsion system consists of two major elements: a gas turbine prime mover driving a high speed generator and an energy storage flywheel with its associated motor/generator and power conversion equipment. The 2.5 MW high speed generator is a three phase, eight pole synchronous machine designed to directly couple to a 15,000 rpm gas turbine. Power from the turbine/alternator system feeds the locomotive dc bus through a conventional full bridge rectifier. The energy storage flywheel features a graphite/epoxy composite rotor operating on active magnetic bearings and is designed to store 480 MJ at 15,000 rpm. An induction motor/generator and variable frequency motor drive provide the link to the dc bus and are used to control power flow into and out of the flywheel. In addition to design and fabrication of the propulsion system components, the project is also developing a distributed control system with power management algorithms to optimize the hybrid propulsion system. Fabrication of the major components of the propulsion system is nearing completion and some preliminary testing of the flywheel and high speed generator has been completed. After completion of the laboratory testing, the propulsion system will be integrated onto a locomotive platform for rolling demonstrations at the Transportation Technology Center test track in Pueblo, Colorado. The paper presents an overview of the propulsion system operation and control strategies, gives detailed descriptions of the major components, and presents component test results.