Discrete Predefined-Time Terminal Sliding Mode Controller for Current Control of PMSM Drives

This paper focuses on the discrete sliding mode control (SMC) method adopted in the permanent magnet synchronous motor (PMSM) current loop control system. Based on the predefined-time terminal sliding mode (PTSM) method, a discrete PTSM and its sufficient conditions for convergence are proposed. Considering that the PMSM current loop control system can be rewritten as a typical discrete first-order multiple-input multiple-output (MIMO) system in practical applications, a discrete PTSM law is further proposed. The effectiveness of the proposed discrete PTSM controller is verified through numerical simulations and experiments on a PMSM drive control test bench. Experiments are conducted to compare different current loop control schemes, which fully demonstrates that the discrete PTSM method proposed in this paper can achieve better dynamic performance of discrete state variables during the convergence sliding process.