Vehicle Refinement and Testing of a Series-Parallel Plug-in Hybrid Electric Vehicle 2014-01-2904
The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech is ready to compete in the Year 3 Final Competition for EcoCAR 2: Plugging into the Future. The team is confident in the reliability of their vehicle, and expects to finish among the top schools at Final Competition. During Year 3, the team refined the vehicle while following the EcoCAR 2 Vehicle Development Process (VDP). Many refinements came about in Year 3 such as the implementation of a new rear subframe, the safety analysis of the high voltage (HV) bus, and the integration of Charge Sustaining (CS) control code. HEVT's vehicle architecture is an E85 Series-Parallel Plug-In Hybrid Electric Vehicle (PHEV), which has many strengths and weaknesses. The primary strength is the pure EV mode and Series mode, which extend the range of the vehicle and reduce Petroleum Energy Usage (PEU) and Greenhouse Gas (GHG) emissions. A primary weakness is the architectures complexity, which made it difficult for the team to truly reap the benefits of the added components to the vehicle which are utilized in Parallel mode. The control system of the vehicle is extremely complicated and is explained in sufficient detail in the Controls System Overview section. The ultimate goal of the control strategy is to meet team Vehicle Technical Specifications (VTS) while performing safely and meeting driver demand. Finally, this paper details the predicted VTS, the modeling and tests done to predict the VTS, and other features of the vehicle which assist in meeting overall competition goals.