Research On Energy Management Strategy Of Composite Power Supply For Micro-Electric Vehicles

In recent years,the growth of vehicle ownership has aggravated the environmental pollution and energy shortage.Under the background of "dual carbon",low energy consumption and zero emission electric vehicle is the focus of development.However,at present,there are still bottlenecks in battery technology.Single battery electric vehicle can not take into account the dual requirements of energy and power density while driving,and the power performance and driving mileage of the vehicle can not be guaranteed.In this paper,a composite power system composed of high power density supercapacitor as auxiliary power and high energy density accumulator is proposed.A logical threshold control strategy and a fuzzy control strategy based on the filter idea are developed to coordinate the rational power allocation between the two energy storage elements in the composite power system,so as to improve the energy utilization rate of the composite power system.To achieve the purpose of extending the range of electric vehicle and battery life.In this paper,a composite power system consisting of lithium iron phosphate batteries and super capacitors is used as the research object,and the working characteristics of lithium batteries,super capacitors and bidirectional DC/DC converters are analyzed.On this basis,the four topologies of the composite power system are compared,and the active controlled supercapacitor topology is selected as the configuration of the composite power system in this paper.According to the "Management Regulations of New Pure Electric Passenger Vehicle Enterprise",the basic parameters and performance indicators of the whole vehicle are designed.By analyzing the power requirement of the motor under typical working conditions,the power system parameters of the electric vehicle are matched.In order to achieve a reasonable allocation of power demand between batteries and supercapacitors,a filter-based logical threshold control strategy and a fuzzy control strategy are developed according to the four working modes of the composite power system.Aiming at the problem that ADVISOR software does not contain composite power supply,the ADVISOR software is redeveloped.The simulation models of lithium-ion batteries,supercapacitors,bidirectional DC/DC and drive motor are established.The simulation model of the whole vehicle is built according to the selected configuration of the composite power system.The simulation analysis of single power system and composite power system under CLTC-P and WLTC conditions respectively shows that the energy control strategy of the composite power system can meet the power performance index of the electric vehicle designed in this paper,and has certain feasibility.Compared with a single power system,the composite power system can make full use of the "peak clipping and valley filling" feature by adding super capacitor,avoid the impact of large current on the battery,shorten the battery life and increase the temperature rapidly,and improve the energy utilization and mileage of the electric vehicle.Compared with the fuzzy control strategy and the logical threshold control strategy,the fuzzy control strategy has stronger robustness and better control effect.Figure 71 Table 20 Reference 75...