Selection Method of Accumulator in HCU Based on Modeling and Simulation

For rail transit vehicles, accumulator in HCU (hydraulic control unit) should be able to support 3~5 times of train brake and release in emergency situation when hydraulic pump can not work. The selection method, presented in this paper, analyzes the work condition and requirements of the accumulator in HCU including: oil consumption when braking and releasing and working pressure when braking. Hydraulic unit was built and verified by AMESim. Pressure change when braking and releasing was emulated by using different size of accumulator models. According to the simulation results, the ideal size of accumulator was selected and the volume was verified.