Study On Energy Management Method For Parallel Hybrid Loader

The loader is widely used construction machinery, which has good mobility,flexible operation and high efficiency, but there are also some defects such as largefuel consumption, the quick loss of main components, emission and noise pollution.In recent years, the energy-saving effect of hybrid technology in the automotive fieldhas been proved, which provides a new way to improve the environmentalperformance of construction machinery. Hybrid energy management method needsto allocate demand torque reasonably based on the characteristics and real-timestatus of power source, select the appropriate operating mode to reduce emissions.Energy management is the key to hybrid loader machine control, which hassignificant influence on construction machinery energy saving and environmentalprotection.Based on the National High Technology Research and Development Programof China (863Program)"New Hybrid Construction Machinery Key Technologiesand Systems," took Liugong CLG856wheel loader as the prototype, designedparallel structure hybrid loader to improve system power and fuel economy. Basedon static threshold logic, the instantaneous fuel consumption and optimum fuzzylogic rules, proposed three hybrid system energy management methods, distributedthe torque demand, optimized operating state of the engine and motor, andconducted the control algorithm simulation and experimental verification.The main contents include: analyzed working characteristics of wheel loaderand the feasibility of hybrid system according to the load spectrum and compareddifferent hybrid system forms. The design of parallel hybrid loader structure,calculation and parameter matching, mathematical modeling of the main component.Proposed three energy management methods for parallel hybrid system based onstatic logic threshold, instantaneous fuel consumption optimization and fuzzy logicrules, used MATLAB software system to simulate the three methods. Finally selected fuzzy logic control method with the best simulation result and conductedbench test. Compared with conventional loaders, the fuzzy logic method saved fuelconsumption up to7.42%. Therefore, the parallel hybrid loader design was provedreasonable, and energy management based on fuzzy logic was effective whichprovided a theoretical basis and practical experience for the development of hybridloader.