Speed Tracking Control Of Electric Vehicles Driven By Permanent Magnet Synchronous Motor

As concern about environment pollution and energy issues, it is necessary to developthe electric vehicle to replace the traditional internal combustion engine vehicle in theworld, which is the trend of world vehicle industry in the future. Driving system is thecore in electric vehicle, and the research of drive motor is directly related to theperformance and cruising ability of the vehicle, which is the guarantee of electric vehiclein industrial production. The driving performances of different motors are compared inthis article. Because of its well characteristics, such as low loss, high efficiency, highpower density and good control performance and so on, permanent magnet synchronousmotor is more and more application in drive system of electric vehicle. Then the model ofelectric vehicle driving system was built up include of permanent magnet synchronousmotor and driveline system.Based on the model for the electric vehicle permanent magnet synchronous motordrive system, this paper proposes two speed tracking control scheme.First, design a speed tracking controller based on all states of system can be measured.Parameters variation and disturbance exist in actual operation, such as the motor statorresistance, the viscous friction coefficient, the friction torque between the wheel and theground, road slope. According to the characteristics of nonlinear, strong coupling of thesystem and parameter variations in the actual system, a nonlinear adaptive controller wasdesigned based on the combination of backstepping recursive design and the decouplingcontrol technique. And Simulation results demonstrate the validation of the proposeddesign.Second, design a speed tracking controller based on sensorless control. In the electricvehicle drive system, using the mechanical sensor will reduce the stability, increase thecost of the system and take up more space, so it is necessary to design a controller withoutspeed measured. This paper uses nonlinear techniques to estimate the speed, and feedbackusing the estimated value instead of the actual speed. Taking into account parametervariations and the external disturbance in the system, such as the stator resistance, air drag force, rolling resistance, the slope of the road and friction torque, an adaptive controllerinclude of an adaptive speed observer, an speed tracking controller and the parameteradaptive laws were proposed, which guarantee the accurate estimates and precisiontracking of speed. And the simulation results show that the controller was able to ensurean accurate estimate of the speed and precision tracking, even in the presence of parametervariations and load disturbance.