At present, the lithium-ion battery (LIB) is the most important candidate for electrical energy storage for different applications, including electric and hybrid vehicles and aircraft. Although many studies have been done so far to evaluate performance and durability of LIB cells and packs for vehicle application, there is no study for the application of LIBs in electric and hybrid aircraft. In this paper, the cycle life and calendar life of a typical aftermarket LIB are studied through an empirical modeling method. The degradation rate of the battery for a typical light-weight passenger aircraft with a flight range of less than 1000 km is presented. The real duty-cycle of the battery for this aircraft is used for the cycle-life analysis.

Analytical and experimental analyses of a variable electromotive-force generator (VEG) show the advantages of this modified generator in hybrid electric vehicle and wind turbine applications with enhancing the fuel efficiency and expanding the operational range, respectively. In this study, electromagnetic analysis of a modified two-pole DC generator with an adjustable overlap between the rotor and the stator is studied using 3-D finite element simulation in ANSYS. The generator stator is modeled with two opposite pole pieces whose arcs span between 15° to 90° in the counterclockwise direction and −15° to −90° in the clockwise direction. A semicircular cylinder whose arc spans between −90° and 90° is used to model the generator rotor. A tetrahedral mesh is used to provide a solution for changes in the electromotive force at different frequencies and overlap ratios. For a constant electromagnetic flux density and fixed number of coils, the changes in the electromotive force at different overlap ratios between the rotor and the stator are obtained in static conditions. There is a very good correlation between the results from simulation and those from analytical and experimental studies.

Reduction of global carbon dioxide emissions is one of the most critical challenges for realizing sustainable society. In order to reduce carbon dioxide emissions, energy efficiency must be improved. Waste heat recovery with external combustion engine is expected to be one of the promising technologies for efficient energy utilization. However, the temperature of waste heat is getting lower with the progress of energy technologies. For example, in Japan which is known as one of the most energy-efficient countries in the world with advanced technologies such as cogeneration and hybrid automobiles, total amount of disposed heat below 300 °C is as much as 10% of the total amount of primary energy supply. Conventional external combustion engines, such as Stirling, thermoacoustic 1 and steam engines 2 show significant decrease in their efficiency at low temperatures below 300 °C. Utilization of high-temperature heat sources, however, requires relatively expensive materials and advanced processing technologies to achieve high reliability. In order to overcome these issues, a novel liquid-piston steam engine is developed, which achieves high efficiency as well as high reliability and low cost using low temperature heat below 300 °C. Present liquid-piston steam engine demonstrated a thermal efficiency of 12.7% at a heating temperature of 270 °C and a cooling temperature of 80 °C, which was about 40% of the Carnot efficiency operating at same temperatures. The liquid-piston steam engine operated even with wet steam, without requiring steam to be superheated. This low temperature operation yielded relatively little deformation of components, which leads to high reliability of the engine. In addition, present liquid piston engine can achieve both high efficiency and low cost compared to conventional external combustion engines, because it has only one moving part whereas both Stirling and Rankin engines have at least two moving parts. The developed liquid piston engine is thus expected to possess large possibility of recovering energy from waste heat.

The global need for environmentally clean yet inexpensive and reliable energy is a problem that has yet to find a solution. • In one corner are coal plants that can generate low-cost power using abundant reserves of coal, but if emissions are uncontrolled, major health and environmental impacts can occur. • In another corner are natural gas power plants that can produce energy with relatively low emissions, but the cost to the consumer is unpredictable and often high. • Yet another option lies with building nuclear plants that produce emissions-free power, but initial costs are very high and some public unease exists with respect to safety. A major complication is the consensus that burning massive amounts of fossil fuels is a primary culprit behind climate change. While intermittent renewable energy (e.g. solar and wind) and conservation practices can help, the undeniable truth is that the vast quantities of power we continuously consume overwhelm the practical capabilities of the “green” sources. Similar in nature to the fundamentals behind the hybrid automobile, Hybrid-nuclear Energy is an emerging 21st century technology that provides an environmentally sound and economical solution to the power and greenhouse gas dilemmas. This developing energy conversion process uses nuclear and fossil fuels to safely produce reasonably priced electrical power and transportation fuels from our own indigenous sources with the timely benefit of dramatically reduced emissions, particularly CO 2 . Hybrid-nuclear Energy secures energy independence by using cleaner coal, effectively solves nuclear and coal waste dilemmas, and helps create more affordable nuclear power. These surprising results are achieved by a unique marriage of helium gas reactor, combustion turbine and coal gasification technologies.

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) conducted development and testing of a 3 MW high speed generator and turbine drive system for a hybrid vehicle propulsion system as a part of the Advanced Locomotive Propulsion System (ALPS) Program [1]. Several critical design issues were identified that apply to high speed wound field synchronous generators and turbine drive systems. The focus of the paper is directed to the more aggressive designs that, like ALPS, are intended to maximize the power density of the turbine/generator package. Design issues addressed by the paper include: • Thermal management for the armature and field windings; • Structural support and insulation of the rotating field winding; • Design of the brushless exciter and rotating diode array; • Design of the rotor bearings, seals, and dampers; • System dynamic response to sudden load changes. The results of trade studies for selection of the generator technology (wound field, permanent magnet, high temperature superconducting) will also be presented to identify key size/weight and cost drivers in the design process. Lessons learned during the fabrication, assembly, and testing of the ALPS generator will be discussed in this paper, in particular, issues concerning the high pressure stator air cooling system, improvements to the field winding insulation, and field coil installation techniques will be addressed. A companion paper will present the results of testing the high-speed generator and turbine drive system to a 1.5 MW power level at NAVSEA (Philadelphia, PA) and UT-CEM with a fixed resistive load.