Research On High-efficiency Control Strategy Of Permanent Magnet Synchronous Motor For Electric Vehicles

Due to increasingly severe resource shortages and environmental problems,energy-saving and emission-reduction is the trend of vehicles industry development and the main aspect of building a resource-economical society.The electric vehicles including battery electric vehicles,hybrid electric vehicles and fuel cell electric vehicles will be the best choice of green vehicles in the future,and the electric vehicle fields are the strategic emerging industry for China.As the main source of power for electric vehicles,permanent magnet synchronous motor(PMSM)is attractive candidates for high performance drive systems because of its high power density,torque density and efficiency.In order to reduce energy consumption and carbon emissions and also increase endurance mileage,this paper proposed a high efficient control strategy of PMSM for electric vehicles.First of all,this paper introduces the basic structure and working principle of IPMSM and analyzes various kinds of efficiency optimization control of IPMSM system.After the comparative analysis,this paper makes a further research on MTPA control strategy based on injection method.On the basis of analyzing the power response and the principle of tracking the optimal current angle,a high efficiency control algorithm for permanent magnet synchronous motor is completed.Moreover,this paper proposes a novel step control scheme to cope better with electric vehicle characteristics of frequent change of driving torque in electric vehicle,and the step angle is generated from the power response and used as compensations for stator current vector toward to MTPA points.This method improves response speed especially in the condition of large variation and only depends on original parameter under various operating conditions,which retain the advantage of the previous algorithm.Secondly,the IPMSM control system simulation model based on JMAG-RT is built by using Matlab/Simulink simulation tool,and the effectiveness of the MTPA control strategy based on injection method is verified and optimized by simulation and the analysis of result.After that,the contrast experiment between step angle compensation strategy and original injection method under the same working conditions verifies the feasibility and effectiveness of the algorithms above.As shown in the result of HIL,this proposed method tracks MTPA trajectory of the IPMSM with faster convergence speed,and adjusts the motor to the efficient operation point quickly and steadily.Finally,the hardware in loop(HIL)experimental platform was set up to verify the feasibility and effectiveness of the program.The real-time simulation environment and data interaction systems are built on the PXI platform by using LabVIEW,and the preparation of control program of IPMSM is consummated with STM32F4 as the master of whole control system.In order to ensure the accuracy and instantaneity of the real time simulation model,the hardware in the loop platform is adjusted and verified through the basic motor vector control to.On the basis of calibration,the semi-physical simulation tests are carried out to evaluate the proposed control system.According to the simulation results and the problems of the experiment,the potential factors of effectiveness are analyzed and discussed thoroughly,and a good foundation is laid for the development of the experimental platform in the future.