Abstract
A fuel cell hybrid bus will be carried out within the end of this year in the framework of a European Project. The motor of the bus is fed by a pack of accumulation batteries that are continuously charged by an electrochemical device. The electrochemical generator is constituted by two stacks of polymeric electrolyte membrane fuel cells (PEMFC): hydrogen coming from a bottle is fed to the anodic compartment and atmospheric air compressed until 1,5 bar absolute is fed to the cathodic one.
The transient response of the electrochemical core during the start up is examined for the bus. Two strategies are individuated to move the air compressor: in the former the self adaptive one, the power electrochemically generated is fed directly to the compressing motor; in the latter, the forced powered scheme, this motor is fed by accumulation batteries. The choice of the self adaptive one is made under technical and economical considerations. Experimental analysis of the power generator system (fuel cells
+ air compressor) is presented. Data show that net power generation is start up phases reaches stand-by values after a short period when the net power generated from fuel cell can be utilised only by the air compressor motor. Successively the air flow is maintained to the operating values by an electronic control.