Drive Control Of Electric Vehicle Based On NVH OptimizationStudy Of The Scheme

At present,with the aggravation of energy shortage and environmental pollution,the development of a new energy vehicle has become a national development must face the problem.Driven by permanent magnet synchronous motor(PMSM).electric vehicles have gradually become the research focus of major automobile manufacturers and research institutions due to their clean energy and excellent power performance.The improvement of motor control technology gradually meets the requirements of control performance of electric vehicles,and with the improvement of life quality,people pay more and more attention to NVH(Noise,Vibration,Harshness)performance of vehicles.The major research institutions gradually changed from improving the control performance of the drive motor to optimizing the performance of the NVH of electric vehicles.Electromagnetic noise is the driving motor caused by the unique noise of electric vehicles.The NVH optimization scheme of fuel vehicle cannot optimize the electromagnetic noise caused by the driving motor,so the optimization of electromagnetic noise becomes an urgent problem to be solved in the NVH optimization of electric vehicle.In this paper,the optimization problem of NVH is studied,and the main research work is as follows:Firstly,the mathematical model of electric vehicle drive motor is introduced,and the mathematical model of three-phase static coordinate system is deduced.Then the basic principle of coordinate transformation is introduced,and the mathematical model of motor in two-phase stationary coordinate system and two-phase rotating coordinate system is deduced.Finally,some classical vector control algorithms are briefly introduced.Second,the factors causing NVH of EVs by driving motor are analyzed,highlighting the influence of torque ripple and electromagnetic force on the vibration of EVs in NVH.Then,the torque ripple caused by current harmonics and normal electromagnetic force harmonics in the driving motor are analyzed,and the influence of current harmonics on torque ripple and normal electromagnetic force is summarized.The relationship between current harmonics,motor vibration and NVH performance of electric vehicles is clarified.Third,according to the limitations of classical control in the operating conditions of EVs,a drive control strategy based on NVH optimization of electric vehicles is proposed.The concept of fuzzy control is introduced into the speed loop of the control system to improve the robustness and disturbance resistance of the control system.The concept of predictive control is introduced into the current loop of the control system and the voltage dead zone compensation is introduced to further weaken the current harmonics.It makes up the shortage of single predictive control or fuzzy control.Through simulation,current harmonics and motor vibration are analyzed to verify the suppression effect of the proposed control strategy on motor vibration.Fourth,the algorithm is simulated to verify whether the function of the proposed algorithm conforms to the standard.Then the hardware platform is built on the basis of simulation.By collecting the noise and vibration of the driving motor in the semi-muffled room,the order and amplitude of the vibration and noise under the two controls are analyzed.The results show that the vibration and noise of the driving motor are significantly reduced.It shows that the proposed control algorithm can reduce the vibration and noise of the driving motor,and can optimize the performance of NVH in electric vehicles.