Research on the cold start performance of fuel cell system for vehicle

• A fuel cell low-temperature shutdown purging model that does not rely on stack impedance was developed, with a maximum impedance error of 4.5% • After 30 times of fuel cell system cold start verification at -30°C on the test bench, the stack voltage decay was 1.3% • The vehicle cold start test was carried out, the start time was 268s, and the power battery SOC maintained a balance To meet the operational requirements of fuel cell vehicles in low-temperature environments, a low-temperature purge impedance calculation model for fuel cells independent of stack impedance detection was developed, with a maximum error of 4.5% between the impedance values calculated by the model and the test values from impedance measuring equipment. A low-temperature cold start control strategy for fuel cells was also developed, which can select different output powers according to the vehicle power demand, covering a range of -2 kW to 16 kW. Bench test results show that the developed low-temperature purge impedance calculation model and cold start control strategy enable 30 consecutive successful cold starts at -30°C, with only a 1.3% attenuation in stack voltage, a 7.0% decrease in the electrochemically active surface area (ECSA) of the first single cell, and a 12.2% decrease in the ECSA of the last single cell. Vehicle low-temperature tests were conducted at -20°C for verification, and the results demonstrate that the fuel cell system (FCS) starts successfully and can respond to the vehicle's power demand.