Abstract
In the near future a significant increase in electric power consumption in vehicles is to be expected. Reasons for this are the increasing standards for safety and comfort and the replacement of mechanical and hydraulic subsystems by electric ones.
To limit the associated increase in fuel consumption (and CO2 emission), smart strategies for the generation, storage/retrieval, distribution and consumption of the electric power can be used by exploiting the fact that the efficiency of the internal combustion engine strongly depends on its operating point (i.e. engine speed and torque) and by making use of the possibility to temporarily store electric energy in an electrical storage device (e.g. a battery or super capacitor). When using such a strategy, electric energy is generated at moments when this would lead to a higher efficiency.
Most of the currently applied strategies are based on optimization of the electrical power flow using only information from the vehicle's current state and the past. This paper discusses the development of a more advanced strategy based on anticipation on upcoming events. A framework is suggested which assumes future information about the vehicle's driving pattern and electrical loads to be known to some extend by using e.g. GPS and navigation systems. Using this framework and a fuel consumption oriented cost function, a control strategy is designed to reduce fuel consumption by changing the operating point of the engine. Model Predictive Control has been chosen because of its ability to minimize a cost function over a certain prediction horizon while satisfying many time-varying constraints.
This strategy will first be tested in a simulation environment and will then be implemented in a hardware-in-the-loop test setup. This makes it possible to compare its performance with other strategies.
Future research will include extension to a vehicle with a dual voltage power net (14V and 42V) and application for parallel hybrid electric vehicles where the generator can also be used as a motor.