The Study Of Topology Optimization And Improved Fuzzy Control Energy Management Based On Electric Hybrid Vehicle

With the increasingly strict carbon emission regulations,new energy vehicles based on pure electric vehicles have been rapidly introduced to the market.However,the shortcomings of the power battery such as short life cycle and poor low temperature performance make the promotion of electric vehicles limited.To resolve these shortcomings,the supercapacitor-lithium battery electric hybrid vehicle is proposed,but it is not widely promoted with its high cost and complicated control.In order to solve the above problems,this paper has proposed a power system topology with lower hardware cost.Based on the topology,in-depth research is conducted on the energy management strategy run on the vehicle controller.The main research contents of this paper are as follows:The topology of typical electric hybrid power system has been analyzed and the mathematical model of key components based on experimental results has been established.The topology of the electric hybrid power system determines the vehicle performance,cost and control mode.In order to limit the system cost and ensure the vehicle performance,the semi-active configuration power topology was selected as the research object.In addition,to ensure the system simulation accuracy,the key components such as the power battery,supercapacitor and bidirectional DC/DC have been analyzed.Moreover,the system model has been completed by experimentally identifying the key parameters.In order to reduce the hardware cost of the system,detailed parameter matching and topology optimization have been performed on the hybrid electric power system.A suitable power configuration can meet system requirements while reducing costs.Combined with UDDS and ECE driving cycle,the CPE function has been used to optimize the configuration capacity of supercapacitors.In the two power system topology,supercapacitor + bidirectional DC/DC and lithium battery + bidirectional DC/DC,a lower cost interleaved parallel bidirectional DC/DC has been used.And the corresponding auxiliary circuit has been redesigned to get better performance.An improved fuzzy energy management strategy has been proposed to reduce the battery decay rate.Because the over-calculated control algorithmhe can't be embedded in the vehicle controller,author has proposed a new strategy by combining the power factor distribution fuzzy control strategy and the lithium battery constant power output control strategy.Compared with the single fuzzy control strategy,the improved fuzzy control strategy can reduce the battery decay rate by 10.03% in the simulation.A hardware-in-the-loop experimental bench has been built,and a test software has been embed to verify the improved fuzzy control strategy.Under ECE and UDDS driving cycle,the performance of the control algorithm embedded in the bench test software is basically consistent with the simulation results,which proves the feasibility of the control strategy that proposed by author.