Hydrogen fuel cell motorcycle with triple hybrid drive train

Abstract

Motorcycles are major vehicles used for mobility especially in Southeast Asia, with their number doubling in the last decade. Motorcycles are also a major reason for air and noise pollution especially in the cities. In this study the hydrogen fuel cell powered motorcycle prototype was designed, fabricated and tested. The design criteria included futuristic style, ergonomic, low noise, zero exhaust emission and high tank-to-wheel fuel efficiency. Other criteria are handling flexibility, dynamic stability, good acceleration under any road and weather conditions. A triple hybrid power train was developed consisting of a 7 kW proton exchange membrane fuel cell, Lithium polymer batteries and super-capacitor connected to an electric drive with two permanent magnet motors. The fuel system consists of two light weight carbon fibre-aluminium cylinders with total capacity of 52 litres storing 1.25 kilogram hydrogen at 350 bar. To ensure its safety against hydrogen leakage, hydrogen leak detectors connected to an automatic hydrogen supply shut-off function was installed. A water cooling system was also designed, fabricated and tested and used to remove the heat produced by the fuel cell stack and power electronics. It keeps the fuel cell stack temperature below 75?. Hollow stressed members of the fuel cell mounting and vehicle frame were used which allowed the flow of cooling water and process media to the fuel cell. An on board data acquisition system was developed to acquire real time data such as speed, distance travelled, hydrogen consumption, power produced and other information. Laboratory test on the analysis and performance of the triple hybrid drive train system used a water brake dynamometers which was customized to collect the required data especially the acceleration response and efficiency of the power train under Worldwide Harmonized Motorcycle Test Cycle 1 and 2 (WMTC). Different hybridization configurations were compared. The main road test was conducted during the successful participation in the technology class, of the 4,000 kilometre South African Solar Challenge 2008. During the real time test, the motorcycle was subjected to different road conditions including steep terrain, flat road, variable weather conditions and endurance. A mobile hydrogen refuelling system was designed to refuel the motorcycle safely and efficient. Results from the endurance test showed that the motorcycle performed according to the design criteria. The maximum speed achieved was 82 km/h slightly lower than the designed 100 km/h due to the road conditions, a trade off from hill climb capability with 30% slope, to maximum speed have been made. The maximum tank-to-wheel fuel efficiency achieved was 42.9% using WMTC2. The best fuel consumption measured was 68.9 km for one litre petrol equivalent. The hydrogen fuel cell motorcycle showed good driving behaviour without fatal breakdown under robust road and weather conditions. Also the triple hybrid drive train was found to increase the peak power by 57% compare to a non-hybrid drive train thereby reducing the fuel cell load cycles by 35%. Finally, the result of the study can be used to predict the range, traveling time and efficiency of the motorcycle or any vehicle using triple hybrid drive train