Permanent Magnet Synchronous Motor Drive System Of Electric Vehicle Based On Predictive Control

The car has been gradually family with China’s economic strength and the rapid development of the automotive industry,but it also brings a series of problems.Vigorously develop new energy vehicles has become the deve lopment trend of China’s automobile industry,both countries and the automobile manufacturers are vigorously promote the development of this industry.Permanent magnet synchronous motor is a kind of motor which is suitable for new energy vehicle driving.In this paper,this kind of motor is chosen as the control object,and its high performance speed control is studied by the model predictive control method.In order to better design and evaluate the performance of predictive control,this paper first models the PMSM.The coordinate transformation——Clark and Park,and the different coordinates are analyzed in detail.The two classical motor control algorithms: vector control and direct Torque control are analyzed,and the control effect of these two methods is given by constructing the simulation model.Finally,The advantages and disadvantages of these two control methods in the electric vehicle industry are expounded.According to the performance requirements of electric vehicle motor control,the research on the predictive torque control is carried out.This part is analyzed from three aspects,including finite control set-model predictive control without weight coefficient adjustment,one-step predictive control and two-step predictive control based on duty ratio modulation.In the finite control set-model predictive control,the method of non-weight coefficient adjustment is designed,and the basic characteristics of predictive control are verified.Aiming at the problem that the torque ripple is large and the switching frequency is not fixed,the predictive control based on duty ratio is studied.For the problem of large computational complexity in the two step model predictive control,a fast vector selection method is proposed in this paper,which greatly reducing the amount of calculation.Aiming at the problem of cost control and reliability of electric vehicle,this paper studies the sensorless control of PMSM,and uses the method of extended state observer to estimate the rotor speed and rotor positi on effectively.Combining this method with the two-step predictive control based on duty cycle,the correct estimation of rotational speed and rotor position is realized,and the robustness of the method is verified.Finally,the model predictive control and the sensorless control are studied under the condition of the vehicle model.The existing vehicle simulation model is used to verify the performance of the proposed control algorithm under different operating conditions,and the correctness and validity of the method are verified.