Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Mechanical and Aerospace Engineering

Committee Chair

Nigel N. Clark.


The WVU Challenge X Team was tasked with improving the fuel economy of a 2005 Chevrolet Equinox while maintaining the stock performance of the vehicle. A through-the-road-parallel hybrid diesel-electric was implemented to accomplish this goal. The greatest potential for improvement to hybrid electric vehicle technology is in energy storage in terms of cost, size, lifespan, and efficiency. Currently, battery cost is limited by the expense of the base materials. The characteristically low power density of electrochemical energy storage rather than energy density is responsible for the size of current hybrid energy storage systems. A limited lifespan is inherent in electrochemical energy storage. The WVU Challenge X Team sought to produce a hybrid electric vehicle with a high power, efficient energy storage system with an extended lifespan and costs not limited by the base materials used in manufacture. The team selected an ultracapacitor pack with an effective energy storage of 0.17 kWh to accomplish those goals. The work presented analyzed this energy storage system, the powertrain architecture associated with it, and the unique control strategy developed to control it. The fuel economy of the stock vehicle was compared with the diesel powertrain only as well as the complete hybrid electric powertrain selected by the team. Road load was calculated over the course of the competition drive cycle and was compared to the power capability for the electric motors. The cycle energy and power were calculated for each braking and power event and the statistics compared with the capabilities of the energy storage system, hybrid electric system, and the actual performance during the 2007 Challenge X competition. The small effect of a 20% reduction in the size of the selected energy storage system and its efficiency were also discussed. Finally, suggestions for improvement to the architecture, design and control strategy were discussed.