Examination of hydraulic hybrid drive unit for PHHV

Nowadays, hybrid drive technology is one of the most significant research fields that has attracted much attention in the last decades. Hydraulic hybrid technologies can improve the fuel (electric) economy by recovering energy. In this paper, a design of a test bench for a hybrid drive unit is presented. This hybrid unit makes the improvement of its efficiency possible, approaching the total efficiency of the vehicle from drive unit to wheel. The presented development contains an e-motors and hydraulic pump/motor (HPM) unit. The experimental hybrid drive unit is designed to reach the highest efficiency during vehicle launching, acceleration and regenerative braking.