Design of a high-speed permanent magnet motor for the drive of a fuel cell air-compressor

This paper deals with the design of a 500 W permanent magnet machine used to drive the air-compressor of a 5 kW fuel cell. The authors focus on the optimization of the motor efficiency in order to minimize the energy consumption of the air-compressor which can represent up to 30% of the electrical energy delivered by the fuel cell. The authors justify the use of a permanent magnet machine by the fact that, by using rare earth Nd-Fe-B magnets, such a type of machine makes it possible to reach a high efficiency as well as a high power density. The optimized machine presented in this paper have theoretically more than 25% of its working area with an efficiency higher than 90% and the efficiency at the rated point equals to 92%. Those promising results of computation are confirmed by the first experimental results obtained with a prototype.