Study on control strategy for parallel hybrid hydraulic excavators

In order to avoid the biased optimization for engine operating point, this paper establishes a mathematical model for the whole efficiency of a parallel hybrid hydraulic excavator, from which a dynamical management strategy and a control strategy are put forward by considering the actual working condition of the excavator and the characteristics of the storage battery. The simulation results indicate that the presented control strategy can adjust the battery in high-efficiency operating state quickly. The feasibility of this strategy is verified by the fact that the fuel consumption detected in a hybrid hydraulic excavator keeps the same by the proposed control strategy and by the maximum efficiency strategy.