Mathematical FCEV System Modeling for Energy-Consumption-Oriented Optimal Design of an Ultra-High-Speed Air Compressor Motor

Ultra-high-speed air compressor motors in fuel cell electric vehicles (FCEVs) are conventionally designed to maximize efficiency at the maximum operating speed. However, under realistic driving conditions, compressor operation is concentrated in the intermediate-speed region, resulting in a mismatch between component-level efficiency optimization and vehicle-level energy performance. This study establishes an integrated FCEV system model to derive the operating-speed distribution of the air compressor motor and formulates a cycle energy objective for the compressor motor that reflects actual driving conditions. An energy-oriented motor design framework is then developed by combining ANOVA-based design variable screening, Latin Hypercube Sampling, Kriging surrogate modeling, and a genetic algorithm. The optimized design maintains the efficiency at the maximum operating speed within 0.04 percentage points (95.82% to 95.78%) while improving the cycle energy efficiency by 0.33 percentage points, from 91.60% to 91.93%. This improvement corresponds to an approximately 3.9% relative reduction in the cycle-averaged loss fraction. The results demonstrate that incorporating the actual operating-speed distribution into the motor design objective can improve vehicle-level energy performance while maintaining the high-speed capability of the air compressor motor.