Sliding Mode Variable Structure Control For Permanent Magnet Synchronous Motor Without Position Sensor

At present,with the development of permanent magnetic materials,the application of permanent magnet synchronous motor is becoming more and more extensive.The rapid progress of industry and science technology makes people more stringent on the control precision for permanent magnet synchronous motor.But because of the structure characteristics of the permanent magnet synchronous motor,and its mathematical models is nonlinear,strong coupling,so a permanent magnet synchronous motor control system is more complex.The variable speed system with high performance for permanent magnet synchronous motor has more and more strict requirements to the control,and sensorless control is widely used in a small volume,high performance and special environment occasions.A sliding mode control system based on a novel reaching law is proposed in this paper.It's only aimed at the structure characteristics and do not rely on its mathematical model for permanent magnet synchronous motor.A chattering suppression method is presented based on a novel reaching law according to the serious chattering problem of sliding mode control,and the stability of the novel reaching rate is proved by the Lyapunov stability theory.It is designed that Current and speed controller of permanent magnet synchronous motor based on a novel reaching rate.Finally,the control system based on a novel reaching rate and a traditional reaching law are compared in matlab/simulink.The results show that the system based on a novel reaching law has a better effect on chattering suppression.A sensorless control system of permanent magnet synchronous motor based on a current error trajectory is presented.Introduction of reference vector based on current error trajectory,determine the symbols of position angle estimation error by the product of the reference vector and the current error trajectory.The current error trajectory circle is given.The amplitude of the motor position angle is calculated by the location relation of the current error trajectory circle.The rotor position is estimated by the product of symbol and amplitude of the position angleerror,so a sensorless control of permanent magnet synchronous motor is realized.Finally,a sliding mode control system based on a novel reaching law and a sensorless control system based on a current error trajectory are established in matlab/simulink,the results show that the sliding mode control system based on a sensorless control for permanent magnet synchronous motor has a good dynamic and static performance,and its control method is feasible.