A Position Sensorless Control Method For PMSM Based On Superhelical Sliding Mode MRAS

Permanent magnet synchronous motor is widely used in many fields because of its high efficiency,low energy consumption and high power density.However,setting the position sensor of the interior permanent magnet synchronous motor will increase the cost,size and weight of the system,and the installation is tedious and has strict requirements for the use environment.This paper studies a method of rotor speed and position estimation of IPMSM based on superhelix sliding mode model reference adaptive method.The basic principle of space vector pulse width modulation technology is clarified.This paper analyzes the principle of coordinate transformation and the mathematical model of PMSM in three different coordinate systems,focuses on the basic principle and implementation process of space vector pulse width modulation technology,and carries out simulation analysis to verify its correctness and feasibility.The magnetic field weakening control method of MTPA based on voltage closed-loop feedback is studied.In order to better carry out vector control of IPMSM,three common vector control methods and characteristics of permanent magnet synchronous motor are analyzed respectively,with emphasis on the principle and realization method of MTPA control and flux weakening control.Then a further study of the MTPA flux weakening control strategy is conducted on,and a MTPA flux weakening control strategy based on voltage closed-loop feedback is designed.The feasibility and correctness of the control strategy are verified by simulation.Aiming at the rotor speed and position estimation of IPMSM sensorless control system,the basic principle of model reference adaptive method is analyzed,and the appropriate reference model and adjustable model are established.The speed adaptive law is designed by using Popov hyperstability theory,and the asymptotic stability of the speed adaptive law is proved.The feasibility and accuracy of the model reference adaptive method are verified by simulation.In order to solve the problem of weak robustness of PI adaptive law in traditional model reference adaptive method,superhelix sliding mode control is introduced to replace PI adaptive law.A model reference adaptive observer based on superhelix sliding mode is designed and the stability of the system is proved.In the case of sudden change of speed and torque,the superhelix sliding mode model reference adaptive algorithm and the traditional model reference adaptive algorithm are simulated and compared.the results show that the superhelix sliding mode model reference adaptive algorithm can improve the dynamic performance and robustness of the position sensorless control system.