Hybrid propulsion systems

Thiokol Chemical Corp, Reaction Motors Div, Study of Reverse Hybrid Propulsion System, Rept RMD 5021, QTSR-1 (Oct to Dec 1962) [Contract N600(19)-59314] (Conf)... 

The incumbent technologies do not stand still, but continue to improve in performance, albeit within the envelope of the other components of the energy system—for example, more fuel-efficient internal combustion engine (ICE) vehicles and hybrid propulsion systems that make better use of the existing fueling infrastructure. 

Corbo P, Migliardini F, Veneri O (2009) PEFC stacks as power sources for hybrid propulsion systems. Int J Hydrogen Energ 34 4635 1644... 

The main issues of hybrid propulsion systems are discussed in this chapter, drawing attention to basic characteristics of power train components and aspects of energy management within each hybrid configuration. The main characteristics of electric drives are described in Sect. 5.2, different types of electric energy storage systems are analyzed in Sect. 5.3 and Sect. 5.4, while different configurations of hybrid electric vehicles are discussed in Sect. 5.5, with particular reference to fuel cell propulsion systems (Sect. 5.5.4). 

BAE presentation BAE Systems Hybrid propulsion Systems at the AB 118 Hydrogen Workshop of the California Energy Commission (CEC) on September 29, 2009, posted at www.eneigy.ca/2009-ALT-l/ documents/2009-09-29 workshop/presentations/. 

The technology of rechargeable lithium batteries is being developed continuously. Goals are larger batteries, e.g. for the hybrid propulsion system of vehicles, environmentally more compatible components, especially for the cathode, lower priced materials, longer cycle lives, more inert electrodes, etc. So-called solid-state batteries with polymeric electrolyte are also to be mentioned here. They are lithium-ion cells with an inert polymer matrix or a gel, which contains the electrolytic solvent-conductive salt mix. Herewith, the use of the normal heavy steel containers, which cannot be manufactured with heavily reduced wall thickness anyway, can be abandoned and a plastic laminated aluminum foil can be applied instead. In this way lightweight and very thin cells of a card format can be made. 

New vehicles, propulsion systems, and fuels are on the horizon hybrid automobiles (combining an electric motor, batteries, and a gasoline or diesel engine), better electric cars, greater use of compressed natural gas (CNG) and propane for urban fleet vehi-... 

Only chemical propulsion will be further discussed, and in particular, that associated with liquid, solid, and hybrid motors and engines. These motors and engines are uniquely different from other chemical propulsion systems in that they carry on board the necessary propellants, as contrasted to jet engines that rely on atmospheric oxygen for combustion of the fuel. 

Besides fuel-cell (electric) vehicles (FCV), there are other vehicle concepts under development, which are also based on electric drives ranked by increasing battery involvement in the propulsion system, and thus extended battery driving range, these are hybrid-electric vehicles (HEV), plug-in hybrid-electric vehicles (PHEV) - which both incorporate an ICE - and, finally, pure battery-electric vehicles (BEV), without an ICE. While electric mobility in its broadest sense refers to all electric-drive vehicles, that is, vehicles with an electric-drive motor powered by batteries, a fuel cell, or a hybrid drive train, the focus in this chapter is on (primarily) battery-driven vehicles, i.e., BEV and PHEV, simply referred to as electric vehicles in the following. 

DOD is interested in new or novel advanced power and propulsion systems that will reduce fuel consumption, improve performance, extend vehicle range, reduce emissions, and reduce support costs. The Navy and Army are considering hybrids for ships, land vehicles, helicopters, and battlefield power requirements. 

Hybrid rocket proplnts hybrid technology provide a number of propulsion-system capabilities in combinations not readily achievable with all-solid or all-liq systems. Foremost among... 

Electric Motors Research Development Electronic Propulsion Systems Hybrid Engine Technology Power Generator Control Systems Software... 

The utilization of fuel cells in propulsion systems for road transport applications raises the question of the optimal hybridization level between on board generation and storage of electric energy (batteries, supercapacitors). 

The simultaneous utilization of FCS and battery within a fuel cell propulsion system can be accomplished by two basic ways (i) the battery pack can be minimized (but not eliminated as in full power) assigning the role of generating most energy required by the load to the FCS (soft hybrid configuration), (ii) the FCS can be sized to provide the base load, i.e. a power value close to the average power of the expectable road mission (hard hybrid configuration), while larger battery pack are necessary to satisfy the dynamic requirements. 

The propulsion system is powered in a hybrid configuration by using lead batteries and the 20 kW PEM stack described in the above paragraphs. The experimental tests in dynamic operation are carried out on a laboratory test bench utilizing the European R40 driving cycle, varying both dynamics and maximum power of the test cycle for different hybridization levels between FCS and batteries. 

Finally, widespread awareness for environmental concerns has sparked initiatives for new car propulsion systems, such as electrical engines in conjunction with batteries and/or fuel cells, and small turbines and hybrid engine systems that include both an electrical engine together with batteries as well as a small internal combustion engine used to reload the battery. Currently, it is believed that electrical engines powered by full cells are most likely to succeed. 

The prognosis, then, for road transportation is for a varied mix of propulsion systems and fuels as conventional petroleum becomes less plentiful and prices rise. Internal combustion engines operating with synthetic liquid fuels (hydrocarbons, alcohols and bio-diesel) are expected to appear in increasing numbers, often supported by hybrid electric drives to reduce fuel consumption. Plug-in hybrid electric vehicles may become popular when more durable and affordable batteries become available. This would allow the power source to be part liquid fuel and part mains electricity. Some of the major obstacles to be overcome with hydrogen-fuelled vehicles are ... 

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