The Research On The Efficience And The Fast Response To The Induction Motor Of The Electric Vehicle

Electric vehicle has advantages of low pollution，low noise，in environmental protectionand energy saving advantages unparalleled. But so far， no enough travel distance is the mainfactor influencing the electric vehicle to go to the market， if we want to solve this problem，we must improve the efficiency of the drive system， to use the energy in the great degree.With small volume， light weight， low cost， easy maintenance and other advantages，induction motor is widely used in electric vehicle motor system.Current research on efficiencyoptimization of induction motor is improving the efficiency by lossing the system dynamicresponse， this is only applicable to the load which require the low dynamic performance.It isnot applicable to the electric vehicle、robot etc which require the high rapid response.Therefore，developed a new control strategy to meet the requirements of the electric vehiclefast dynamic response and high efficiency is imminent.This paper first discusses the control technology and the development trend of electricvehicle: efficiency optimization of induction motor，technology present situation of fastdynamic response field，the research focus and development trends， and lists the mainresearch content of this paper.Then established the mathematical model of induction motorconsidering iron loss，and gave the corresponding equivalent circuit diagram，using thesimulation software MATLAB/Simulink to build the simulation model.Electric drive system requires torque response with the wide speed range and fasterresponse.The first，contrast with induction motor torque expression and magnetic linkageexpression，with weak magnetic efficiency optimization of induction motor is analyzed on itsdynamic response speed;Then in accordance with the need of high speed electric vehiclefaster dynamic response to complete the requirements of speeding up，torque response controlstrategy proposed high-speed area.According to the dynamic voltage limit amount to adjustthe excitation current and torque current of motor， to ensure that any time in the process ofdynamic torque output value is about maximum.It broke through the limitations of thedynamic torque output ability when steady state of the maximum torque control strategy todeal with the problem.The simulation results show that the control strategy can provide greater dynamic output torque，reduce the effect of the original efficience optimal control forthe effect of dynamic response speed in high speed zone.