Improvement of Energy Saving for Hybrid Hydraulic Excavator with Novel Powertrain

Abstract

To reduce the energy consumption and emission, an innovative powertrain and the energy management strategy are proposed for hydraulic excavator in this paper. The novel powertrain consists of the engine, motor/generator, planetary gear, gearbox, and variable hydraulic pump. The energy regeneration system is also applied on the system to regenerate the potential energy and charge the battery. An improved equivalent consumption minimization strategy is proposed to control the engine, motor/generator, hydraulic pump and gearbox. The engine working points can be located in high efficiency range, with the proposed powertrain and the energy management strategy. To verify the energy saving efficiency of the proposed system, the test bench is built in laboratory. Compared with the current hybrid system, the energy saving efficiency reaches 11% in condition of a large velocity. Compared with the current hybrid system and conventional system, the energy saving efficiencies are 4% and 48% respectively with different cylinder velocities. The fuel consumption and emission of hydraulic excavator can be reduced effectively with the proposed powertrain and energy management strategy.