Research On Fuzzy Energy Management Strategy Of Series-parallel Hybrid Electric Vehicle

Hybrid electric vehicle has become one of the effective solutions to the environmental pollution and resource shortage because of its low energy consumption,low emission and reliable technology.The design and optimization of reasonable control strategy is the key to enhance the performance of hybrid system.In this paper,the fuzzy rules in the fuzzy controller of the series-parallel hybrid electric vehicle are optimized by single objective and multi-objective genetic algorithm.By contrasting to various vehicle arrangement forms,the series-parallel vehicle is selected as the research object.Considering on the system work mode and energy flow under each mode,the selection and parameter matching of vital transmission components are completed.The entire vehicle and its components model are built based on forward modeling thought through the Simulink simulation platform.The whole control strategy consists of three parts: component control,brake control and drive control.Component control is developed by the rules of component status transition during mode switching.Brake control and drive control are separately set up by the rules of regenerative braking energy distribution as well as the rules of fuzzy control.Due to certain subjectivity in the design of fuzzy control strategy,The strategy needs to be further optimized to enhance the control effect.The single objective(GA)and multi-objective genetic algorithm(NSGA-III)are designed and used respectively to optimize the control rules of fuzzy contoller under WLTC(World Light Vehicle Test Cycle).Compared with non optimized strategy,the results show that the single objective optimization strategy can effectively reduce the fuel consumption and energy consumption of battery pack after driving cycle.Compared with the single objective optimization strategy,the driving fuzzy control strategy based on multiobjective optimization of NSGA-III algorithm can improve engine performance and driving motor efficiency,further reduce fuel consumption and emissions of the whole vehicle,and reduce the cost of the battery pack on the basis of its power balance.