The Research Of Sliding Control Method Based On Permanent Magnet Synchronous Motors

Permanent magnet synchronous motor(PMSM)has attracted more and more attention because of its simple structure,high power density and low power consumption.It has been widely used in the field of Engineering.Many scholars pay more and more attention to the direct torque control of permanent magnet synchronous motor(PMSM).This paper introduces the application status of permanent magnet synchronous motor sliding mode variable structure in direct torque control system,and aiming at the problem of large flux and torque ripple,robustness and other issues,has been improved,the main contents are as follows:First of all,the system for the traditional PI controller for direct torque control of speed change caused by inherent and unable to track the given speed direct torque flux and torque fluctuation problem in finite time,put forward a fuzzy nonsingular terminal sliding mode controller to replace the PI controller,described in detail the implementation process of the method,and the validity of the method is verified by simulation;Secondly,according to the reference voltage vector loop output accuracy of the system the problem of low voltage vector reference presents a fractional order direct torque NTSM controller to replace the voltage space vector control method,and the simulation results show that this method further reduces the torque and flux fluctuation,and effectively improve the system dynamic and static performance;Finally,in order to effectively reduce the torque and flux fluctuation,according to the global fast terminal sliding mode control method and the fractional calculus theory,the design of a fractional order sliding mode speed controller based on the simulation results show that this method is better than the former two more effective in reducing the torque and flux fluctuation,and can ensure fast tracking speed.