Research On Energy Management Control Strategy Of Distributed Electric Drive Loader

Distributed electric drive loader transmits power in the form of electricity.Distributed electric drive loader is driven by motor and has flexible structure,high transmission efficiency,good dynamic performance,and significant advantages in energy conservation and intelligent control.It can effectively improve engine fuel efficiency through energy management control strategy,which can improve fuel consumption and emission performance of loader.Based on the projects of our team(20160101285JC,51875239),aiming at the problem of energy management,two rulebased energy management control strategies are proposed for distributed electric drive loader,which realize the optimal control of the engine operating point and the coupled output of the engine and supercapacitor power,and improve the fuel economy of the whole vehicle.The main contents are as follows:(1)The overall framework of energy management and control for distributed electric drive loader is constructed.Combining with the structural characteristics and technical advantages of distributed electric drive loader,the overall framework of hierarchical control system including power identification layer,operation strategy layer,engine operating point control layer and power coupling output layer is constructed.The power identification,control strategy construction and power coupling between different power sources in power system of distributed electric drive loader are analyzed and planned.(2)The simulation models of key components of distributed electric drive loader power system and the joint simulation platform on the basis of AMEsim & Matlab are established.Based on the theoretical analysis of the working principle of the key components such as engine,generator,supercapacitor and motor,the theoretical calculation model for the solution of the vehicle's demand power is established.By the use of AMEsim model library,the physical models of key components such as engine,generator,supercapacitor,motor and reducer for forward simulation are established.The performance parameters of key components are configured according to the actual working cycle of loader,and the joint simulation platform on the account of AMEsim&MATLAB is built.(3)Two rule-based energy management control strategies are built,and the simulation analysis of the control strategies is completed.According to the load characteristics of V-shaped working cycle,the multi-mode switching control rules of explicit rule energy management control strategy are formulated.The control model is established,and the optimum working curve of engine is figured out.Based on the principle of fuzzy logic control,the membership function of the fuzzy logic controller is defined and the fuzzy control rules are formulated.The construction of the fuzzy logic control strategy and the simulation analysis are completed.The simulation results show that the two rule-based control strategies can both realize the optimal control of engine operating point and effectively improve the fuel economy of the whole vehicle.By comparison,the explicit rule energy management control strategy is simple and practical.The fuzzy logic energy management control strategy is more smoother for the control of key components.(4)The safety and feasibility of explicit rule energy management control strategy are verified by designing test scheme,building data acquisition system,bench test and vehicle test.Combining with the hardware configuration of the distributed electric drive loader test platform,the test scheme is designed.In order to meet the test requirements,a data acquisition system based on Dspace Rapid Control Prototype System is established.The control of engine operating point and the coupling of engine and supercapacitor output power are realized by controlling rectifier current.The bench test with fixed resistance as load and the real vehicle test under driving cycle are completed,which prove the feasibility of the proposed energy management control strategy for vehicle application.The energy management control strategy proposed in this thesis and its research results lay a foundation for the next research of energy-saving control method of distributed electric drive loader,and provide a reference for the research of energysaving technology of construction vehicle.