Tham khảo tài liệu 'new trends and developments in automotive system engineering part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 16 On the Control of Automotive Traction PEM Fuel Cell Systems Ahmed Al-Durra1 Stephen Yurkovich2 and Yann Guezennec2 -Department of Electrical Engineering The Petroleum Institute Abu Dhabi 2Centerfor Automotive Research The Ohio State University 930 Kinnear Road Columbus OH 43212 1 United Arab Emirates 2USA 1. Introductin A fuel cell FC is an electro-chemical device that converts chemical energy to electrical energy by combining a gaseous fuel and oxidizer. Lately new advances in membrane material reduced usage of noble metal catalysts and efficient power electronics have put the fuel cell system under the spotlight as a direct generator for electricity Pukrushpan Stefanopoulou Peng 2004a . Because they can reach efficiencies of above 60 Brinkman 2002 Davis et al. 2003 at normal operating conditions Proton Exchange Membrane PEM fuel cells may represent a valid choice for automotive applications in the near future Thijssen Teagan 2002 Bernay et al. 2002 . Compared to internal combustion engines ICEs or batteries fuel cells FCs have several advantages. The main advantages are efficiency low emissions and dual use technology. FCs are more efficient than ICEs since they directly convert fuel energy to electrical energy whereas ICEs need to convert the fuel energy to thermal energy first then to mechanical energy. Due to the thermal energy involved the ICE conversion of energy is limited by the Carnot Cycle not the case with FCs Thomas Zalbowitz 2000 . Fuel cells are considered zero emission power generators if pure hydrogen is used as fuel. The PEM fuel cell consists of two electrodes an anode and a cathode separated by a polymeric electrolyte membrane. The ionomeric membrane has exclusive proton permeability and it is thus used to strip electrons from hydrogen atoms on the anode side. The protons flow through the membrane and react with oxygen to generate water on the cathode side producing a voltage between the electrodes Larminie Dicks 2003 . When the gases are .
