Abstract
Keywords - Vehicle power net, energy management, regenerative braking, mild hybrid electric vehicles, fuel reduction
Abstract - In the near future a signifcant increase in electric power consumption in vehicles is to be expected. To limit the associated increase in fuel consumption and exhaust emissions, smart strategies for the generation, storage/retrieval, distribution, and consumption of the electric power can be used.
This paper considers two strategies for energy management: a regenerative braking strategy and a more advanced strategy based on optimization techniques. To explain the energy management potential behind these strategies, typical characteristics of components that are directly related to the energy flow in a vehicle will be discussed.
Although it seems a contradiction, the advanced energy management strategy does not aim at operating the internal combustion engine in the area with the highest efficiency. It will be shown that the method considered here is a better solution to the energy management problem than one that considers the efficiency map of the engine.
Subsequently, engineering rules are presented to estimate the performance that can be expected for each strategy. These rules apply to a vehicle configuration with a conventional drive train. The characteristics of components are included as input parameters to make the method general applicable.
To show the value of the engineering rules, the potential fuel reduction is computed for a specific vehicle configuration and drive cycle and compared with simulation results.