Regulating And Matching Of Traction Motor For Parallel Hybrid Electric Vehicle

As the deficiency of petroleum resources and the pollution of the environment, conventional vehicle exposes a lot of shortcomings. And EV (Electric Vehicle) technology about battery storage will not be resolved in a short time, so to develop and produce HEV (Hybrid Electric Vehicle) is necessary.Traction motor system ,as an key component of hybrid electric vehicle,which selection,dynamic characteristics and parameters matching impact directly on the vehicle design. In view of the recent growing interest in HEV demands for an high reliance, high performance, high efficient, low cost motor drive for electric propusion ,so optimization and regulating performance of traction motor has gradually become an important subject for HEV.The goal of this paper mainly to improve fuel economy of hybrid electric vehicle, regulating and optimizing the efficiency map contour of motor. Within the scope of motor overload ability , matching the rated power according to the different road conditions . While studying the performance of the traction motor, a higher demand of motor design is needed .First, the paper introduces the types and performance of motor , control strategies for motor and controller and the latest trends. The international research trend for HEV engine and motor in control strategies and designing is compared and analysed.Then the paper studys on the mechanic performance , efficiency region and speed region of induction motor,including their mutual relations in turns. The mechanic performance is introduced with conventional vehicle's ideal drving characteristic field. The main analyse is put on the calculation and regulation of theinduction motor.According to speed character of the induction motor, the relation of constant-power region and overload region is concluded .then the relation of constant-power region and efficiency region of induction motor is also analysed qualitative. The optimal base speed ratio is determined by the way of simulation.Then a method for the paramter macthing design of parallel hybrid electric vehicle power train based on vehicle cycle condition and their evaluation are put forward. According to the demand of traction motor power in different cycle conditions,the power region of motor which is used mostly is determined in the condition of the overload region,then the rated power of induction motor is matched.The average speed is regarded as the evaluation of dynamic character and exhausted energy of motor in certain time regarded as the evaluation of economic character, the comprehensive evaluation is the system efficiency of motor in the road.At last, four typical domestic city bus cycle conditions are selected, which are Beijing,Changchun,Uk,WVUCITY.Then the motor for 40kw in the HEV Bus of FAW is optimized . At the beginging ,the rated power of motor matching for the four bus cycle conditions are determined . Assumed that the percentage of the stray loss in all losses is constant. Using scaled coefficient refering to the electrical efficiencyof themotor for 40kw,four motors'efficiency are calculated .Establishing a motor model in Matlab/Advisor with the converter efficiency of experimental date,a simulation is carried on in every city cycle condition.After finishing the simulation ,it is proved that the motor's operation points in high efficiency region increase obviously and improve the fuel economy.Three evaluations for the motor matching for the cycle condition ,such as average speed,exhausted energy of motor in certain time and system efficiency of motor in the road. In these simulations, average speed is unchanged and others are improved.