Adaptive thermal management for cooling parasitic power reduction in FCEVs

Fuel cell electric vehicles (FCEVs) require thermal management to keep the stack temperature within an allowable range, but cooling auxiliaries (pump/fan) consume parasitic power that can degrade hydrogen fuel economy. This study proposes an adaptive-bias near-open valve control strategy that reduces cooling parasitic power while preserving temperature regulation. The controller uses the parasitic-power cost to update a small valve bias under fuel-cell-load gating and temperature/overcooling constraints, and applies first-order lag and slew-rate limits to suppress chattering and repeated saturation. The strategy was evaluated using a validated, control-oriented 100 kW-class light-duty FCEV integrated model over UDDS, FTP-75, HWFET, and US06, with fuel economy compared using SAE J2572 SOC correction. Across all cycles, the proposed controller reduced parasitic power and improved SOC-corrected fuel economy relative to baseline PI valve control by 2.05% (UDDS), 2.55% (FTP-75), 7.22% (HWFET), and 2.13% (US06). These results suggest that cost-driven valve operating-point adaptation can reduce cooling parasitic power and improve SOC-corrected fuel economy within the tested driving cycles, while retaining a PI-compatible supervisory structure.