On the development of power drive trains for hydrogen fuel cell electric vehicles

Abstract

The world faces a major problem. Fossil fuel sources are finite and the economic and environmental cost of those that actually remain make finding an alternative one of the great technological challenges of our age. Nearly 70% of refined oil is used for transportation making it one of the key sectors where change could yield large-scale global benefits. Combustion engine passenger vehicle technology is after a long period of stagnation progressing at a pace. Hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs) are also starting to penetrate the mass market. Unfortunately, HEVs do not remove our dependency on oil and the prospects of battery technology advancing sufficiently to allow BEVs to progressively replace the entire oil fuelled vehicles are currently slim. Their limited range and long recharge times prohibit them being useful for most modes of driving. One solution to the problem may be hydrogen fuel cell electric vehicles (H2FCEVs) as they offer great promise, but realistically face many challenges. The fuel cell allowed man to voyage to the moon in the 1960s and recent material advances have enabled them to be packaged into motor vehicles, so providing a zero emission replacement for the internal combustion engine. However, substantial infrastructure and geopolitical changes are required to make hydrogen production and delivery economic but this gas potentially offers a clean and sustainable energy pathway to entirely replace fossil fuels in motor vehicles. Few reported studies have comprehensively examined the optimal method of building power drive train subsystems and integrating them into an architecture that delivers energy from a fuel cell into driven road wheels. This project investigated the optimisation on the most efficient drive train topology using critical analysis and computer modeling to determine a practical system. No single drivetrain was found suitable for all driving modes and worldwide markets as the current ones typically offered either optimal performance or optimal efficiency. Consequently, a new drivetrain topology was proposed, developed, tested with a simulation environment that yielded efficiency and performance gains over existing systems. Also analysed was the effect of wider vehicle design optimisation to the development of sustainable hydrogen powered passenger vehicles and this was set against the wider social, scientific and engineering challenges that fuel cell adoption will face.