Fuel processor-battery-fuel cell hybrid drivetrain for extended range operation of passenger vehicles

Abstract Power required to run auxiliary systems on a passenger car, such as those for air conditioning and advanced vehicle control, reduces the driving range of a vehicle equipped with a hybrid drive train. Under practical driving conditions, a significant amount of additional energy is required at low power levels compared to the rated power of the drive unit. In the present study, we consider a fuel cell-battery drive train augmented by an on-board fuel (ethanol) processor to provide the motoring power requirements of a car. Using systematic driving cycle simulations that take account of power-to-weight, energy-to-weight and power-to-efficiency factors of on-board power sources under simulated load conditions, we show that a combination of steadily-operated compact ethanol reformer, a low-power battery continuously charged by excess reformer capacity and a high-power fuel cell powered by conservatively-used hydrogen from cylinder can increase the range of hybrid fuel cell drivetrains to about 750 km. Although the overall energy consumption of the three-way hybrid is more than that of fuel cell-battery hybrid, lesser use of stored hydrogen improves the fuel economy of the hybrid drivetrain. While the system complexity is increased, long-range distressed mode operation becomes feasible with the added fuel processor.