Research On Sensorless Control Strategy Of Permanent Magnet Synchronous Motor Based On Convex Optimization

With the continuous development of modern science and technology,due to the excessive exploitation and use of energy,countries around the world have begun to experience an energy crisis.New energy vehicles are an energy-saving policy that China has begun to develop and implement in recent years.The state maintains support for the development of new energy vehicles.And new energy vehicles have higher and higher requirements on drive motors and their control systems.Taken together,permanent magnet synchronous motors are the main development direction of new energy vehicle drive motors.Therefore,studying the performance improvement of the permanent magnet synchronous motor and the optimization of the drive control system,and analyzing the key factors that affect its important performance are of great significance for expanding its application range,improving control effects,and optimizing the efficiency of the motion system.Since the installation of position sensors on the motor will also bring a series of problems,the sensorless control algorithm of permanent magnet synchronous motors has gradually become a research hotspot in the academic field and engineering application research and development field at home and abroad.In view of the above,this paper simplifies the calculation of the traditional permanent magnet synchronous motor based on convex optimization position observation algorithm without the need to estimate the speed and position at the same time,and analyses and demonstrates its convergence.The main contribution is to reduce the calculation amount of the existing convex optimization-based estimation method.Since the speed of the motor changes much slower than the position,it can be considered as a constant between two and three samples.A significant advantage of this scheme is the calculation of single-variable optimization,which greatly reduces the calculation burden of two variables.Then,the traditional vector control and direct torque control strategies were improved respectively.A speed controller based on boundary layer sliding mode was added to the vector control strategy.The space vector pulse widthmodulation strategy(SVPWM)and the traditional direct conversion The moment control methods are combined with each other,a MATLAB / Simulink simulation model is built,and the improved position estimation algorithm is added to the two control systems.Simulation experiments are carried out,and the experiment proves that the algorithm has good track tracking effect.Finally,by adding feed-forward high-frequency voltage signal injection and phase-locked loop(PLL),focusing on the optimization of the observation effect when the motor is running at low speed.