<p>In T-type three-level rectifiers, traditional PI control often suffers from sluggish dynamics, while conventional super-twisting sliding mode control (ST-SMC) is prone to chattering and waveform distortion. To tackle these challenges, this study introduces a modified ST-SMC approach that incorporates a hyperbolic tangent function. In the voltage outer loop, the continuous hyperbolic tangent function is substituted for the discontinuous signum function used in the conventional ST-SMC algorithm. This modification facilitates a smooth transition of the control signal, effectively mitigating system chattering caused by high-frequency switching and enhancing power quality, while preserving the strong robustness of the super-twisting algorithm. For the inner loop, model predictive control (MPC) is adopted to achieve rapid and precise tracking of current commands. Furthermore, the construction of a voltage-error-based integral sliding surface serves to remove any steady-state deviation. Results from comparative simulations and experiments involving PI control and conventional ST-SMC confirm the effectiveness of the proposed strategy. It successfully mitigates chattering and substantially lowers the total harmonic distortion of the grid-side current, while simultaneously maintaining rapid dynamic response and superior system robustness.</p>