An improved air spring model for pantograph on the high-speed train

Air spring’s modelling is a relevant subject in the railway field, both for bogie and pantograph suspensions. Considering thermodynamic model has a great advantage for its accuracy and reliability, efforts and huge progress have been made before. However, there are still some parts where efforts could be made: although the air spring’s force and displacement’s relationship: F/x is mostly important, the thermodynamic model should theoretically demonstrate the relationship between different parameters, allowing to express the ratio between air spring’s pressure and displacement: Pa/x. By starting from some basic thermodynamic equations, this paper aims at modelling the relation Pa/x, with reference to an air spring of a high-speed train’s pantograph, with a pressure regulator mounted in the pneumatic system. Three different models have been proposed stage by stage. They are all validated by comparing simulation results with experiment results for frequency characteristics, the last one gives the best fit with the most cost. three models’ characteristics have all been explicated and differences have also been summarized.