Experimental study on thermal characteristics of fuel cell vehicles under transient operating conditions

The thermal stability of fuel cells directly affects their performance and service life, and the thermal stability under transient operating conditions is particularly critical. To investigate the thermal management characteristics of fuel cell vehicles (FCEVs) under transient conditions, this study takes a proton exchange membrane fuel cell (PEMFC) hybrid vehicle as the research object and conducts real-vehicle thermal characteristic tests on a chassis dynamometer. The thermal response characteristics of the FCEV under the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) and the China Light-Duty Vehicle Test Cycle (CLTC) are quantitatively compared. Based on the test data analysis, the mechanism of fuel cell temperature control lag under high load is revealed. To address the temperature control lag under high-load conditions, a hybrid control strategy combining dual PID cooperative decoupling and segmented threshold control is proposed. This strategy strictly limits the maximum outlet temperature of the fuel cell stack to within 75°C under the WLTC extra-high-speed condition, eliminates the uncontrolled dynamic temperature difference of up to 8°C in the original system, and achieves a quantitative improvement in thermal stability.