Study On Energy Management Control Strategy Of Coaxial Hybrid Electric Vehicle

Under the dual influence of protecting ecological environment and the policy requirement of new energy development,hybrid electric vehicles have been developed by leaps and bounds.Among them,hybrid electric vehicles have developed different types of structures.Coaxial hybrid electric vehicles are favored by various research institutions and automobile companies because of their simple structure and high fuel economy.But because hybrid cars have several power sources working together,it is important to allocate energy accurately and efficiently.In terms of improving fuel economy,adopting advanced and excellent robust energy management strategy can achieve remarkable results.In this paper,a small passenger vehicle is taken as the research object to study the energy management strategy under the condition of coaxial parallel configuration.The specific contents include:(1)Based on the analysis of different hybrid electric vehicle configurations,the hybrid electric system structure of coaxial parallel hybrid electric vehicle is determined,and the parameters of the core power components are calculated and selected.(2)The energy control strategy based on determination rules was constructed,different working modes of hybrid electric vehicles were analyzed,the entry conditions and torque distribution principles of different working modes were determined,the thresholds of key parameters were determined,and the control flow of vehicle energy management strategy was set up.On this basis,the energy management strategy model of Simulink was established.(3)Through the analysis of different energy management strategies,the fuzzy control system is selected as the optimal management strategy.A fuzzy controller with the ratio k of SOC and demand torque to the optimal engine operating torque as input and the output as engine torque output coefficient y is proposed and fuzzified.The fuzzy subset and control strategy are written through investigation and reference.Finally,the fuzzy control strategy model is established.(4)Cruise software was used to build the vehicle model,connect the bus signal,and the control strategy model in Matlab/Simulink was used for simulation,and the simulation results of the two energy management strategies were analyzed.Under the working conditions of NEDC,the vehicle can run normally,and the fuzzy-optimized energy management strategy has better fuel economy.