Control strategy of a novel energy recovery system for parallel hybrid hydraulic excavator

With the high fuel prices, the demands for energy saving and green emission of engineering machinery have been increased rapidly. Due to the complex working condition and frequent load changing, the efficiency of the hydraulic excavator is low. The aim of this article is to propose a control strategy for energy recovery system of hydraulic excavator driven by the parallel hybrid system. The mathematical models of the main components and the simulation models of the proposed system and a conventional energy recovery system are built. Then, according to the load characteristic, a control strategy based on the working condition and state of charge of the battery is given. The co-simulation for the hybrid hydraulic excavator system is established. The results show that the proposed energy recovery system and control strategy can not only improve the energy recovery efficiency but also reduce fuel consumption and emission of the power system.