Least Costly Energy Management for Extended Range Electric Vehicles with Start-Up Characterization

Abstract

In this work, the Energy Management Strategy (EMS) problem is solved considering an Electric Vehicle (EV) equipped with a Range Extender (REX), a device developed to increase the All Electric Range (AER) provided by the battery, which can be switched ON and OFF depending on the need. First, a control-oriented modeling of the powertrain is introduced focusing attention on REX description in terms of power generation, and thermal dynamics. Secondly, the EMS problem is formalized as a mixed-integer convex program. Thus, the optimal energy management policy is obtained by minimizing an objective function taking into account electricity and battery aging costs, REX fuel consumption and start-up costs. The introduction of REX thermal dynamics allows for temperature varying start-up costs and simplified REX aging modeling. To show the effectiveness of the EMS, an electric bus case study is dealt with and a sensitivity analysis is performed over some critical optimization parameters to understand when purchasing a REX is interesting and economically effective.