Multi-Layer Energy Management System for Cost Optimization of Battery Electric Vehicle Fleets

One of the biggest barriers for a wider adoption of Battery-Electric Vehicles (BEVs) is their relatively higher cost compared to their combustion-based alternatives. A potential solution is to develop Energy Management Systems (EMSs), which make a more efficient use of the vehicle energy, resulting in a cheaper operation. EMSs are commonly composed of algorithms operating at fleet and vehicle layers. For example, at fleet layer one can find eco-routing for optimising the vehicle route, and eco-charging for smart charging. Likewise, at vehicle layer one can find algorithms such as eco-driving for minimizing speed-related losses and eco-comfort for minimizing the thermal-components energy consumption. These eco-functions affect the operational cost of the fleet due to reduction of metrics such as energy consumption and travelling time (which impacts labor costs). This paper presents the development of a multi-layer EMS, which integrates the aforementioned fleet and vehicle-level eco-functions. The paper focuses on the energy and operational cost savings that such a multi-layer EMS can bring to a fleet owner. Simulation results show that the EMS saves on costs produced by travelling time and energy consumption. However, the ideal ratio between these savings ultimately depends on the region, as electricity price and labor costs vary greatly.