Energy saving of hybrid hydraulic excavator with innovative powertrain

An innovative hydraulic hybrid excavator is proposed in this paper to save energy. An electrical hydraulic continually variable powertrain is proposed to drive the main pump, in which both the speed and torque of the engine can be controlled to ensure that the engine working points lie in the high efficiency range with the proposed energy management strategy. An energy regeneration system is adopted to regenerate the potential energy. In addition, an innovative equivalent consumption minimization strategy is formulated to calculate the control commands of the engine, motor/generator, and hydraulic pump to reduce the energy consumption of the system. A test bench is established, and experiments are conducted to verify the energy saving efficiency of the proposed system. As a result, the energy saving efficiency ranges from 36.69% to 45.16%. The fuel consumption and emission of hydraulic excavator are reduced effectively with the proposed system.