Experimental research into the low-temperature characteristics of a hydraulic damper and the effect on the dynamics of the pantograph of a high-speed train running in extreme cold weather conditions

There is likely to be a demand to run high-speed trains in extreme cold weather conditions in the near future; therefore, it is important to study the change in the characteristics of the materials and components in an extreme cold environment and their effects on the vehicle system dynamics. Experimental research into the low temperature characteristics of a pantograph hydraulic damper was carried out in this study. The results show that low temperature causes an increase in damping forces, and when the temperature is above the boundary temperature range, most indices of the damping capability increase with the decrease of temperature; when the temperature is below the boundary temperature range, most indices decrease with the decrease of temperature. Key parameters are identified to obtain the theoretical description of low-temperature damping characteristics using a simplified-parametric damper model and the experimental data. A mathematical model of the pantograph–catenary system incorporating the pantograph damper model is then established to calculate the effect of the damper performance on the pantograph dynamics low temperatures. Simulation results show that the lowering performance of the pantograph deteriorates noticeably due to the unstable low-temperature damping characteristics, but the deterioration of the raising performance and contact quality of the pantograph due to the low-temperature characteristics of the damper are less obvious. The results obtained in this study are valuable for understanding the low-temperature characteristics of a hydraulic damper, and instructive in the optimal specification of the pantograph damper for high-speed trains running in cold weather conditions.