The low-voltage ride-through control strategy based on model predictive control is highly dependent on the actual parameters of the control system, and parameter mismatch has a great negative effect on the output current. To solve this problem, this paper proposes a LVRT-MFPC (low-voltage ride-through based on model-free prediction control) control strategy for three-level NPC inverters. The control strategy only uses the sampled current of different control periods to update the LUT (lookup table), and uses the relationship between the current gradient and the voltage vector to update the current gradient corresponding to the full voltage vector, thus reducing the negative impact of parameter uncertainty. In addition, the adjacent vector strategy is used in predictive control to reduce the computational burden of the control algorithm. The simulation results show that the dynamic and steady-state performance of the proposed method is similar to the low-voltage ride-through method based on model predictive control, and it shows good parameter robustness under the disturbance of system parameters.

low voltage,ride-through,three-level,NPC inverter,lookup table,current gradient,robustness