Fuel economy analysis for a hybrid concept car based on a buffered fuel-engine operating at an optimal point

摘要

A hybrid car is conceptually described and analyzed which meets the goal of a factor of three improvement in fuel economy set by the government-industry collaboration, Partnership for a New Generation of Vehicles, announced Sept. 29, 1993. This car combines an internal combustion engine with a low-energy, but high-power capacity, storage unit, such as a capacitor or flywheel. The storage capacity is one-half kWh. All energy requirements are ultimately met from the fuel tank. Essentially all the performance achievements of current conventional cars are met by this hybrid. Two versions of the hybrid are considered: one in which the vehicle loads are the same as those of the average 1993 car, but the drive train is replaced with a hybrid system; and one where, in addition, the vehicle loads are reduced, at fixed performance and interior volume, to levels slightly beyond the best achievements in current production vehicles. The first of these vehicles has a fuel economy twice that of the average 1993 car; the second three times. Thus, the hybrid drive as such yields a factor of two; while practical load reduction yields a factor of 1.5 in fuel economy.