Electric driving is generally limited to short distances in an
emission sensible urban environment. In the present situation with
high cost electric storage and long charging duration hybridization
is the key to enable electric driving. In comparison to the
passenger car segment, where numerous manufacturers are already
producing and offering different hybrid configurations for their
premium class models, the two wheeler sector is not yet affected by
this trend. The main reason for the retarded implementation of this
new hybrid technology is its high system costs, as they cannot be
covered by a reasonable product price.
Especially for the two wheeler class L1e, with a maximum speed
of 45 km/h and an engine displacement of less than 50 cm₃, the cost
factor is highly important and decisive for its market acceptance,
because the majority of vehicles are still low-cost products
equipped with simple carbureted 2-stroke engines.
Hybridization of this vehicle class is therefore a very
cost-sensitive task and enforces low-cost solutions.
The present paper (within the framework of the ECO-PowerDrive
project conducted at the Institute of ICE, research area design,
located at Graz University of Technology) assesses a hybridization
concept with range extender. Special emphasis is put on the
interaction of the main components - generator and combustion
engine - in order to deduce specifications. The application of a
simple port-scavenged two-stroke engine is evaluated on the basis
of experimental data and simulation results with respect to the
principles of economy, emissions and consumption.
Part reduction and system simplification are the keys for a
suitable cost-efficient hybrid system.