The invention relates generally to the field of vehicle propulsion systems. In particular, the invention concerns an on board recharging system for a battery powered electric vehicle.
As concerns surrounding traditional energy sources persist, investigation into alternative forms of energy are becoming increasingly important. In particular, environmental and political concerns associated with combustion based energy systems can not be ignored. In an effort to reduce dependence on these types of energy supplies and methods, therefore, the focus is likely to be on devices capable of generating electricity by consuming plentiful or renewable supplies of fuels without requiring combustion.
In addition to being utilized for the generation of electricity, however, combustion based fuels are most commonly utilized for driving motor vehicles. Indeed, motor vehicles are among the chief consumers of combustion based fuels and, therefore, they are among the chief contributors to pollution problems associated with such fuels. So, while alternative energy sources such as nuclear and hydroelectric systems may be suitable for large scale electric utilities, for obvious reasons they do not present an ideal solution to the problems associated with motor vehicle power requirements.
Alternatives to internal combustion engine powered motor vehicles have included various types of battery powered electric vehicles. A problem associated with most known battery powered vehicles, however, is the constant need for recharging which requires taking the vehicle out of service.
Fuel cells, therefore, have been explored as a means for powering electric vehicles and reducing the constant need to recharge the vehicle from off-board sources. Fuel cells electrochemically convert hydrocarbons and hydrogen to electricity- No combustion reaction is needed. Because they are compact in structure, high in efficiency, and low in pollutants, fuel cells provide several advantages for use in vehicle transportation. Accordingly, they appear to be well suited for adaption for motor vehicle applications.
A drawback associated with known fuel cell systems, however, is that they are not economically viable for applications in which the power rating of the fuel cell must meet propulsion demands. In motor vehicle applications, for example, a fuel cell system designed to provide sufficient power required by the vehicle for cruising, let alone for peak surge, would be prohibitively expensive. While various known systems have attempted to exploit the advantages of designating a surge battery to meet peak demand in motor vehicle applications, none has satisfactorily overcome the economic problems.
It is an object of the invention, therefore, to provide a system for powering a motor vehicle which does not require a combustion reaction. It is another object of the invention to provide such a system which has a range comparable with that of traditional combustion engines without requiring interruptive recharging from off-board sources. It is still another object of the invention to provide an economically feasible system for powering a motor vehicle which can accommodate typical motor vehicle surge and range demands.