While driving conventional vehicles, most drivers will not turn off and on their engines frequently while they are travelling at 30 MPH. The HEVs (Hybrid Electric Vehicles), however, may do just that without consulting the drivers. Hot engine starts/stops are unique to HEVs, but they are not an issue for conventional vehicles. Therefore, very little attention has been given to the hot engine start/stop phenomenon, which is both complex and difficult to study. On the basis of this limited study, the following conclusions are summarized: (1) Conventional engine starting is too harsh for HEV operation, and starting with a larger motor at a higher voltage makes the start much smoother (almost transparent) to the driver. (2) Hot starting the HEV engine with a big motor causes bursts in hyrocarbon emissions probably because of over-fueling by design to ensure a smooth start. (3) Highly hybridized HEVs (such as the Prius) have numerous engine starts/stops, depending on the driving cycle. The engine out hydrocarbon emission characteristics due to these starts/stops are important for optimizing emission control system. (4) The negative impacts of engine starts/stops are beyond hydrocarbon emissions. These may include valve deposit and premature engine failure related to inadequate lubrication. (5) Incremental improvements in engine design to reduce start-up hydrocarbon emissions should be an alternative because heated catalysts and absorbers are not proven technology and consume extra energy.
Engine start characteristics of two hybrid electric vehicles (HEVs) - Honda Insight and Toyota Prius
Die Motor-Start-Eigenschaften zweier Hybridfahrzeuge: Honda Insight und Toyota Prius
2001
13 Seiten, 11 Bilder, 6 Quellen
Conference paper
English
British Library Conference Proceedings | 2001
|Automotive engineering | 2001
|British Library Conference Proceedings | 2001
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