A Fuel-Cell Vehicle Test Station

Abstract

Due to concerns about energy security, rising oil prices, and adverse effects of internal combustion engine vehicles on the environment, the automotive industry is quickly moving towards developing efficient “green” vehicles. Fuel cell-powered vehicles offer high efficiency and practically zero emissions. The main obstacles for widespread commercial production of fuel cell vehicles are high cost and short lifetime of fuel cell stacks, lack of a hydrogen infrastructure, and generation of hydrogen in an environmentally-friendly manner and its storage. Using actual fuel cells and actual vehicular loads in the study of fuel cell vehicular systems can be prohibitive due to cost (initial and running) and safety issues. It is very desirable to have a test station that emulates a vehicle with a high degree of accuracy and flexibility to alleviate cost and safety issues. This thesis proposes a design for a test station that emulates the drive train of a typical fuel cell-powered vehicle that is equipped with regenerative braking capability. As part of the test station, a fuel cell emulator is designed and validated through simulation based on the Nexa Fuel Cell power module manufactured by Ballard Power Systems. As another building block for the test station, a bi-directional controllable DC load is developed that can realize a given drive cycle for the scaled-down version of a given vehicle. The load allows simulation of regenerative braking capability. The performance of the load is validated through simulation. A DC-DC boost converter for controlling the fuel cell power, as well as an energy storage system for assisting the fuel cell in providing the required power during high-demand periods, are incorporated into the proposed test station. Simulation results are used to show that the test station is capable of simulating the real-life conditions experienced by actual fuel cell vehicles on the road. The test station, when realized by hardware, can be used for performing a wide range of studies on the drive train architecture and power management of fuel cell vehicles.