Modeling for control and optimal design of a power steering pump and an air conditioning compressor used in heavy duty trucks

The hybridization and electrification of powertrains has brought increased flexibility and, therefore, new challenges, in the design of the hybrid vehicles. Beside the main components that are used for vehicles propulsion, important energy consumers are the auxiliaries such as the power steering pump or others. The influence of these components on the fuel consumption can be defined in terms of the topology, technology and control algorithm choices. This paper presents the influence on fuel consumption of two auxiliaries for two different topologies. For this purpose models are developed for the power steering pump and for the air conditioning compressor, auxiliaries that can achieve significant fuel benefits by electrification. These models are validated using experimental data from components used in long-haul heavy duty trucks. A case study on the control for the power steering pump is also presented. The results show a significant fuel reduction for each component (for the power steering pump approximately 50% fuel reduction and for the ACC approximately 40% fuel reduction).