Control of a fuel cell vehicle thermal management system

Effective and efficient cooling is essential for the operation of fuel cells as well as batteries. Fuel cells and batteries must be operated in a narrow temperature range for optimal operation and minimal degradation. This paper presents a thermal management method for a fuel cell hybrid vehicle with a metal hydride storage while accounting for all major heat sources and heat sinks as well as the passenger compartment. The thermal management system consists of a superior state machine, which activates underlying controllers for keeping the battery, fuel cell and interior at the desired temperatures and protecting the motor and the power electronics. The system proves successful. The battery was held at 26°C and the fuel cell at the desired temperature of 55°C. Synergies such as using the waste heat for heating the passenger compartment and using the chiller for cooling battery and vehicle interior have been successfully implemented.