In order to solve the problems of high cost, low reliability, unstable performance, and difficult maintenance in the complex working conditions brought about by traditional mechanical sensors to the permanent magnet synchronous motor (PMSM) control system, a continuous hyperbolic tangent function sigmoid is first proposed as the variable-structure model of the switching function. It refers to the method of the model reference adaptive system (MRAS) observer to estimate the motor speed and rotor position. Secondly, in view of the inherent chattering and poor robustness of the traditional sliding mode control (SMC), a speed-loop control strategy of nonsingular fast terminal sliding mode control (NFTSMC) is proposed. On this basis, a new type of reaching law with an improved terminal attractor that can eliminate negative exponential terms is designed. This control technology can quickly converge under conditions of sudden load changes and motor parameter changes, and improve the dynamic response of the system. Finally, simulation and experimental verification are carried out based on PSIM software and the PTS-3000 experimental platform. The results prove that MRAS positionless control can accurately estimate the rotor speed and position, and the NFTSMC based on the improved terminal attractor has superior control performance.
Cite this article as: Q. Ai and Y. Chen, “Research on NFTSMC speed control of improved terminal attractor of permanent magnet synchronous motor based on SM-MRAS,” Electrica., 22(2), 329-341, 2022.