A three-dimensional model of the fuel cell was established by COMSOL software, and the effects of three parameters (operating temperature, oxygen concentration and membrane thickness) on the performance of the fuel cell were studied. The results show that the fuel cell performance can be improved by increasing the operating temperature, and the suitable operating temperature range is 160~180 ℃. The output performance of the fuel cell is obviously improved by increasing the oxygen concentration, but the fuel cell performance is reduced by increasing the thickness of the film. The optimal membrane thickness is 20~ 60 µm.

In order to solve the defects of decreased vehicle comfort of pure electric passenger car when air conditioning system is turned on to cool the power battery, this paper, combining actual development projects, determined the typical travel chain of electric vehicle according to the sales target area of developed vehicle, and formulated the annual calendar driving conditions of electric vehicle according to the travel chain. The vehicle bench environment simulation test was carried out according to the annual calendar driving conditions, and the statistical analysis of the battery temperature distribution in three states of the vehicle in driving, charging and storage within one year was completed according to the test results. The battery cycle life evaluation was completed, and the influence of each operating condition of the vehicle on the battery life attenuation was decomposed, and the battery cooling system control strategy was optimized. The results indicate that, the proportion of cooling system engaged in the battery cooling process decreases greatly, air conditioning comfort improves obviously.

In order to explore an effective test method for the thermal management performance of 48 V power battery, the thermal management performance of 48 V battery was studied and tested on a vehicle equipped with P0 mild hybrid system under different test conditions, ambient temperature and air conditioning mode. The results show that the World Light Vehicle Test Cycle (WLTC) is the most suitable to verify the thermal management performance of the 48 V battery. The high temperature performance of 48 V battery can be effectively verified by continuously performing 5 WLTC test cycles at a high temperature of 30~50 ℃, the low temperature performance of 48 V battery can be effectively verified by continuously performing 8 WLTC test cycles at low temperature of -25 ℃. The internal and external circulation mode of the air conditioner impacts the thermal balance temperature of the 48 V battery remarkably.

In this paper, the applicability of DIN 75220 Aging Automobile Components in Solar Simulation Units to the typical dry, humid and hot climate environment in China was studied by comparing and analyzing the light, temperature and humidity conditions and vehicle test results in the environmental chamber and atmospheric exposure tests. The results show that the nighttime temperature of the simulated dry hot climate environmental cycle conditions in DIN 75220 standard is higher than the winter nighttime low temperature of domestic dry hot climate environment, and the nighttime temperature and humidity in the simulated humid hot climate environmental cycle test conditions is lower than the nighttime temperature and humidity in the domestic humid hot climate environment. The cycle test of DIN 75220 for 600 h is equivalent to 6~7 months of dry hot atmospheric exposure test and equivalent to 8~9 months of humid & hot atmospheric exposure test, which can reflect about 69% of the test problems occurred in 6~9 months of atmospheric exposure test.

To obtain the vehicle’s sprung mass and unsprung mass accurately, this research used the characteristics of the relative positions of the sprung mass and unsprung mass, with the height of the vehicle’s center of gravity with different body attitude as the reference, to derive the parameters required to calculate the unsprung mass, then calculate the corresponding unsprung mass based on the measured vehicle gravity center height and other parameters. Finally, the unsprung mass was weighed by disassembling a real vehicle. Test results show that the results of calculated unsprung mass are close to those of measured results, which proves that the research approach is feasible.

This article studied the ultimate strength bench test method of suspension system of passenger vehicle, it firstly compared and analyzed the characteristics of strength test of vehicle, suspension system and parts, and then introduced the test method of suspension ultimate strength test from the working condition and selection of the definition, the loading form of the load, test equipment and test bench design, test data acquisition and processing, and proposed the way to the evaluate test results. Finally, the paper illustrated the application of the combination of suspension system and component strength bench test with an actual case, and explained the role of suspension strength bench test in product development.

In order to explore the impact of rims with different widths on handling stability, the tire contour scanning test, static stiffness test and six-component force test, subjective evaluation test and objective test of real vehicle handling and stability were carried out. The static characteristics of tires with different widths of rims were analyzed and compared through static test and research on the bench. The actual dynamic performance of tires was analyzed and compared through subjective and objective test of real vehicle handling and stability. The change trend of vehicle handling stability was explored when the same tire was mounted on the wheel hub with different width. Bench test results show that the wider the wheel hub is mounted, the higher the vehicle handling stability is. The subjective and objective test results of the real vehicle also confirm this conclusion.

In order to find out the cause of ablation of transfer case input rear end cover of a vehicle in the driving process, this article analyzed the failure mechanism in lubrication capacity design, oil leakage from transfer case, amount of lubricating oil filling, faulty oil absorption of emergency pump, lubricating oil passage blockage, failure of lubricating oil pump and so on, and concluded that this failure was mainly caused by insufficient amount of lubrication oil filling, resulting in insufficient amount of oil splashed from the output gear in the bottom, which caused poor lubrication of the bearing. Failure reproduction proved accuracy of the failure analysis and positioning.