Abstract：To solve the problem of neutral point voltage imbalance when the three-level neutral point clamped

（NPC）inverter works，an improved neutral balance model predictive control（INB-MPC）algorithm was proposed.

The proposed method used a two-stage voltage vector selection method with no weighting factors，deleted the space vector with large common-mode voltage，and constructed redundant virtual short vectors that has no effect on the neutral point to balance the neutral point voltage. Compared with the traditional low common mode voltage

algorithm，the proposed algorithm has lower midpoint ripple and less computational burden. The simulation results

show that the proposed algorithm reduce the neutral point voltage ripple，and can realize the tracking of reference

current and the reduction of common-mode voltage，and the system has good dynamic and static performance.

      Key words：three-level neutral point clamped（NPC）inverter；model predictive control（MPC）；neutral point

voltage；virtual voltage vector；common-mode voltage（CMV）