Energy consumption of parallel type hybrid electric vehicle with continuously variable transmission using electric oil pump

This paper presents a design of electrified hydraulic control system for a parallel type hybrid electric vehicle (HEV) with continuously variable transmission (CVT). Considering the hybrid characteristics and CVT feature which requires high line pressure to supply the demanded clamping force, three electrified hydraulic system: (1) 1-MOP+1-EOP, (2) 2-EOP and (3) 1-EOP were proposed and the energy consumption was evaluated. The EOP displacement was designed considering the demanded flow rate and pump efficiency. To investigate the amount of flow, pressure and energy consumption of the electrified hydraulic control system, an AMESim-MATLAB/Simulink co-simulator was developed for the target HEV, which consists of the vehicle powertrain and hydraulic system model. From the simulation results, it was found that 2-EOP system shows the smallest energy consumption while satisfying the required control, lubrication and leakage flow.