The development and implementation of a control system for a hybrid electric vehicle

In this study a complete control system for a parallel hybrid electric vehicle is developed from a theoretical standpoint and experimentally proven to provide performance similar to a conventional automobile. The vehicle chosen for this research is the UT-HEV, a 1995 Dodge Neon which was converted into an electric assist parallel hybrid vehicle for competition in the 1995 Hybrid Electric Vehicle Challenge. The approach to control system design includes a treatment of basic hybrid vehicle issues as well as the detailed development of models for both the electric motor and the internal combustion engine. From these models, a vehicle simulation was created to analyze the response characteristics of different control strategies. The control system was implemented through an embedded microcomputer control system coupled to various system components. The control software was developed to implement control of electric assist, regenerative braking, engine-driven charging, and pure-electric operation. Finally, empirical testing determined the final choice of control strategies for the vehicle. These tests focused on the system response characteristics as well as the vehicle's energy efficiency. The final control system has been proven to provide vehicle performance and response similar to today's typical vehicles.