Electric Hybrid Bus Simulation and
External reviewer: Anders Malmqvist, ABB,
The work presented here deals with evaluation
and optimisation of the tractive system in hybrid electric buses. The work
is based on analytical simulation models that are verified via measurements.
The main results of the work are:
· An optimised composition of the
traction system topology, regarding the size of the different components
in the drive train with respect to the performance and emission at a given
· A charging strategy taking into
account a predicted drive cycle, the SOC of the batteries and the instantaneous
· A transient emission measurement
(TES) method for Internal Combustion Engines.
The simulation model concerns all the major
power flow, vehicle speed, temperatures and Internal Combustion Engine
(ICE) parameters of the busses. The model is verified through measurements
on two hybrid buses in Malmö and Stockholm. The ICE models are verified
through test bench driving, both by an external partner and by Lund University.
The predicted drive cycle proposed here is based on position
measurements of the bus relative to the
route. With the proposed changes in composition and charging strategy,
one of the buses studied can reduce the battery weight with 60 %, the fuel
consumption with 10 % and the size of the ICE with 60 %. As a part of the
work with measurements on the busses some practical
experience of handling the vehicles have
been gained, some of which are also presented in this report.