Research On The Power Drive System Of Hybrid Electric Vehicle

Hybrid Electric Vehicle (HEV) is equipped with two power systems, a gasoline engineand an electric motor. At the same time, the characteristics of low pollution and low fuelConsumption makes it a feasible solution of elevating the energy crisis and environmentalprotection problem.As a main part of HEV, Power drive system plays an important role inHEV development. It is of great academic and practical significance to realize its controlalgorithm.In order to meet HEV’s high efficiency and low emissions performance, measureshave been carried out.Parallel-series hybrid electric vehicle system structure has beenconstructed. The high energy and long-life lithium-ion battery is chosen for HEV’s electricdrive system.And the Permanent Magnet Synchronous Motor (PMSM) is chosen as thedriving motor in this subject with it’s high work efficiency, high power density andfavorable speed adjustment performance.Based on the mathematical model of PMSM,The method has been adopted, whichcombines The electric drive system by interval control:then maximum torque/currentcontrol, flux-weakening control and max torque-per-voltage control, in order to meet theHEV power drive system requirements While the car is starting and accelerating, themaximum torque/current control strategies is used.When the car has a high-speed,flux-weakening control and max torque-per-voltage are used for interval control.These twocontrol modes are constant power weakening control. Simulation results show that withvector control strategies, the elecric motor could provide a large torque when the speed islow.It could meet the requirement of a rapidly start.By the power weakening control,the carcan get a higher speed and has a broader speed range.Flux-weakening control and maxtorque-per-voltage control can fulfill the high power requirement for HEV’s high speed.Based on the theoretical analysis, HEV’s PMSM power drive system has beendesigned. The power drive system circuit used TMS320F2812for the main controlchip.Hardware circuit includes: power driver circuit, control circuit, the detection circuitand system protection circuit. Modular design was used in the software systemdesign,includeing the main system routine, the interrupt service routine,fault protectionprogram design and realization of SVPWM procedures.Finally, through the experiment based on software and hardware platform,the experimental data and waveforms has beenobtain. According to the data, the power drive system is reasonable and meets therequirements of the HEV’s power drive system.