Research On Energy Management Strategy Of Hybrid Power System Based On Particle Swarm Optimization Fuzzy Control

In response to the two major problems of environmental pollution and resource consumption,it is imperative to develop new energy technologies represented by pure electric vehicles.Limited to the lack of specific power and low cycle life of the vehicle power battery,the energy source of the pure electric vehicle power system has been gradually developed from a single power source to a combination of two or more energy storage devices.This paper has been taken the power system of combination of lithium battery and super capacitor as the research object,and has been carried out the research of technology of energy management strategy of dual-source hybrid system.The main research contents are as follows:Analysis of the power characteristics of lithium iron phosphate batteries and super capacitors.According to the characteristics of large energy density of lithium battery and high power density of super capacitor,the working mode and topology of typical dual-source hybrid system has been analyzed.According to the lithium battery as the main energy source,the super capacitor as the auxiliary energy source,The topology has been designed as the super capacitor series bidirectional DC/DC converter is connected with the lithium battery in parallel.The vehicle model has been designed based on Matlab/Simulink.The equivalent circuit model of lithium battery and super capacitor and the efficiency model of bidirectional DC/DC converter has been established and combined with load condition module and power bus module into a hybrid system model.At the same time,according to the vehicle parameters and performance indicators of the hybrid vehicle,the key parameters of the drive motor and power system has been designed and matched.The research on energy management strategy of hybrid system combined lithium battery and super capacitor has been carried out.An energy management strategy based on fuzzy control has been designed.Then due to the design of the fuzzy controller is subjective,and it is difficult to obtain the global optimal solution.It has been proposed to reduce the vehicle energy consumption and the lithium battery loss as the optimization goal and use the particle swarm optimization algorithm to optimize the fuzzy control membership function parameters.The results has been showed that in the optimized hybrid system;super capacitor can meet the requirements of instantaneous dynamic load,the charge and discharge current of lithium battery is limited to 1C and the optimized system energy consumption and lithium battery loss under UDDS conditions were reduced by 0.65% and 4.5% respectively before optimization,and by 0.81% and 6.3% under ECE*5 conditions.In order to verify and evaluate the energy management of hybrid system.A powertrain test bench has been established.The energy management strategy based on particle swarm optimization fuzzy control has been tested;under the test bench..The test results has been basically consistent with the simulation results,and the system energy consumption and lithium battery loss under UDDS and ECE*5 conditions are not more than 8.5% with simulation results,which proves the effectiveness of the strategy in practical engineering applications,and provides a reference for the design of dual-source hybrid systems and energy management strategies.