Modeling, design, control and optimization of hybrid vehicles.

The aim of this talk is to propose a framework for the analysis and design of hybrid vehicles. We postulate that hybrid vehicle analysis and design is concerned with the storage of energy in three domains - chemical, mechanical, and electrical - and with energy conversions between these domains. Some of the conversions are bi-directional (e.g.: motor-generator action), some are not (e.g.: fuel chemical-to-mechanical energy via thermal engine). Each domain is characterized by energy storage devices (e.g.: fuels, batteries, flywheels), and the energy conversion devices form links between domains. Energy conversion devices belong to one of two types: inter-domain and intra-domain. The former (e.g., electric machine, combustion engine), perform a conversion between domains; the latter convert energy within one domain (e.g.: gearbox, power electronic converter, fueling system, fuel reformer). We observe that control actions always take place at the intra-domain energy converters (shifting gears, controlling fuel flow, controlling electrical power flow); thus, we allow these elements to be multi-port elements with additional control inputs. The talk will present a normalized and unified description of hybrid vehicles based on composable and scalable subsystem models, and will introduce a number of optimization and control problems that arise in connection with the design of hybrid vehicles and of related control strategies.