This paper analyses the Stirling-Electric Hybrid concept under development at Teknik, Ekonomi, Miljö, (TEM), a R&D foundation at the University of Lund, Sweden. The project is based on a new patented Stirling engine concept that generates electricity in a completely sealed unit, eliminating the need for a working gas make up system, which until now has been typical for kinematic Stirling systems. With its tested high energy-conversion efficiency, extremely low exhaust- and noise-, as well as vibration emission levels, the concept is identified as one of the most promising contenders as a unique drive system for ultra low emission city vehicles. The proposed concept is a drive system combining electric and combustion engine power. Primarily an electric powered vehicle, it carries a small Stirling-engine converter with a directly driven generator coupled to the batteries. The Stirling engine-generated power is used for propelling the vehicle when power requirements are low, charging the batteries with excess power automatically when the batteries are low until the batteries are fully charged. When the vehicle operates in environmentally sensitive areas, the driver has the option to prevent the Stirling engine from operating. (A)
Abstract