Fast High-Order Terminal Sliding-Mode Current Controller for Disturbance Compensation and Rapid Convergence in Induction Motor Drives

By ensuring the finite-time convergence to equilibrium point under disturbance, the high-order terminal sliding-mode (HO-TSM) current controller can improve the system robustness for induction motor (IM) drives. However, the existing HO-TSM still suffers from the drawback that it cannot obtain rapid convergence and effective chattering suppression simultaneously. To address this problem, a fast HO-TSM current controller is studied with the modifications from three aspects. First, a fast HO-TSM surface is designed to improve the convergence speed when the system state is on the designed surface. Second, the control law is modified with a linear integral term to enhance the capability of disturbance compensation. Third, a nonlinear gain is introduced to adjust the gain value, leading to satisfactory chattering suppression during steady state. Compared with conventional HO-TSM, the studied method can achieve strong robustness to disturbance, rapid convergence, and improved chattering suppression capability at the same time. Finally, the superiority of studied method is verified by the experimental results from a 3.7 kW IM test bench.