Control of the Start/Stop of a Diesel Engine in a Parallel HEV with a Belted Starter/Alternator 2007-24-0076
The matching of a starter alternator and an internal combustion engine is an easily realizable hybrid electric vehicle (HEV) configuration to achieve significant fuel economy savings in urban driving. Many examples are found today in production or near-production gasoline hybrid vehicles, with implementation through either belted starter/alternators or integrated starter/alternators. One of the key factors in the successful implementation of the starter alternator technology is the ability to start and stop the engine quickly and smoothly, without compromising the Noise, Vibration and Harshness (NVH) vehicle signature. This issue becomes even more critical in case of Diesel hybrids, as the peak compression torque is much larger than any Spark Ignition (SI) engine.
The paper presents modeling and experimental results on a recent production, 1.9l Common-Rail Diesel engine belt-coupled to a 10.6kW permanent magnet motor. A model of the Diesel engine dynamics, estimating the instantaneous torque and speed, was developed and identified with experimental data from an engine and BSA system implemented in a midsize prototype SUV. The validated model is then used to design a closed loop controller for starting and stopping the engine following a prescribed speed trajectory.