| The development of vehicle facing two major themes:environmental protection and energy saving.Governments around the world are exploring new ways,on the one hand to control the emissions of pollutants from vehicles,on the other hand,promote development and application of a variety of clean technologies.Because of its simple structure,low-emission and even zero-emission,low noise and energy-saving advantages,PHEV(parallel hybrid electric vehicle)becomes one of the automobile industry research and development hot spot.Battery management technology,regenerative braking,motor and its drive are key technologies of PHEV,Paper focuses on these issues.Firstly,a variety of battery's advantages and disadvantages are analyzed,and determine to use lithium-ion battery to storage energy.On the basis of PHEV power need model,lithium-ion battery parameters is decided,and protection circuit based on R5421 is studied.To protect MOFET normal work in low voltage,the lower limit of lithium-ion battery self-locking circuit based on CD4011 is put forward;To eliminate lithium-ion battery voltage difference after large current charging and discharging,lithium-ion battery equalization circuits based on R5421, TL431 and flying capacitor are put forward.More accurate,reliable access to battery SOC is the most basic and most important task in PHEV management system,as a direct reflection of the value of battery,is one of the important parameters to the vehicle control strategy.It is the decision of PHEV to allocate power to engine and motor,as well as important factor to optimize PHEV energy management system,improve battery efficiency and reduce the cost of battery.In the paper,traditional method of lithium-ion battery SOC forecast is analyzed,and points out the drawbacks of traditional SOC forecast methods,then put forward a SOC forecasting method based on fuzzy control,in the Matlab simulation environment,lithium-ion battery SOC prediction simulation is builded,results coincide with experiments.Smart lithium-ion battery management system based on TMS320LF2407A is desiged and tested to cater for the special need of PHEV. Subsequently,constraint factors to PHEV electric charge mileage are studied.Although low battery power density affects their electrical distance, frequent braking in the city running conditions,as well as no recovery of downhill braking energy also is one of important reasons.By analyzing,vehicles use 30%of its energy for braking,the rational use of electric braking,not only to provide auxiliary brake function for PHEV,improve the PHEV braking performance,but also through the braking energy recovery to conserve energy and extend the PHEV electric mileage,so under the present circumstances,research of the PHEV regenerative braking is a very meaningful work.In the light of super capacitor and battery respective merits,braking system based on hybrid power supply system is proposed,and then through matlab simulation model of hybrid power supply braking system is builded,the parameters of SC is determined according to energy recovery.To improve performance of system,equalization circuit of super capacitor is designed.In PHEV control system based on hybrid electric power,the main task of control strategies is how to allocate torque to engine and motor acording to their energy,strategy based on fuzzy control theory is proposed to replace the logic threshold control strategy.With the help of ADVISOR,simulation of this control strategy are analyzed,results show that PHEV's performance based on fuzzy control strategy is far better than the performance based on threshold logic control strategy.Then,Bi-directional DC/DC converters used in PHEV are analyzed.From analysis of common bi-directional isolation DC/DC converter topologies, bi-directional half-bridge converter topology is adopted.Bi-directional half-bridge converter operation mode based is analyzed,according to DC/DC converter design requirements,the parameters of converter components are determined;Simulation model of bi-directional DC/DC converter is established based on Matlab/simulink, simulation results prove the correctness of theoretical analysis and calculation. Realization of the DC/DC converters is discussed,including the design of hardware and software,on the basis,experiment test of bi-directional half-bridge converter is completed.Finally,PHEV power drive system is studied experimentally.To meet the special requirements of PHEV motor:high-speed,high efficiency,high power density,low ripple torque,a new type permanent magnet synchronous motor ---Halbach motor is introduced in this paper.Through detailed analysis of its basic principles and characteristics,refer to traditional PMSM design,use field-circuit method,Halbach permanent magnet synchronous motor's computer-aided design program based on Matlab language and its finite element analysis model based on ANSYS are established.According to traditional PMSM DTC control theory, Halbach PMSM DTC model is realized.Software and hardware design of Halbach PMSM drive system based on PHEV is studied,experiments of vector control and DTC are studied on the test platform,results show that Halbach PMSM under DTC control has a better value and prospects in PHEV.
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