Energy management strategy development of a forklift with electric lifting device

In recent years, the forklift is facing two challenges energy saving and environmental. However, the hydraulic forklift has low transmission efficiency and energy efficiency. To solve the problem, this paper proposes an approach for the lifting hydraulic cylinder replaced by ball screw device. The lifting system is controlled directly with an electric motor drive instead of pump. First, we analyzed the working condition and energy flows of the forklift and proposed an energy recovery system for forklift. Second, we built the system model including supercapacitor model, vehicle model and the simulation model in AMESim. Due to the markedly changing loads, supercapacitor with high specific power and high durability seems the best choice for energy storage system. In addition the study of rule-based energy management control strategies on forklift with electric lifting device is discussed, which is validated and evaluated by simulation. The results show that the fuel consumption of the forklift with electric lifting device can be reduced by about 46.72% compared with the hydraulic forklift and its transmission efficiency is improved 82.3% when the loads is 3t. The energy saving effect of electric system is very significant. - Highlights: • We present an approach for forklift with its lifting hydraulic cylinder replaced by ball screw device. • The transmission efficiency of electric lifting device is up to 82.3%. • We propose a rule-based energy management control strategies on forklift with electric lifting device. • We use the supercapacitor as the energy storage system, and maximum recovery efficiency of the electric system is 46.72%.