To address the neutral-point voltage imbalance problem of three-level NPC converters, a novel neutral-point voltage balance control algorithm based on virtual space vector is proposed. The method reoptimizes the partitioning and reduces the 6 small sectors in the conventional virtual space vector pulse width modulation algorithm to 5 small sectors, reducing the computational effort. Meanwhile, the regulation factor of neutral-point voltage is introduced, and the influence of virtual vector on the neutral-point voltage is used to fine-tune the size of the regulation factor, and the neutral-point voltage is controlled by a kind of hysteresis loop control for neutral-point voltage balancing. Simulation and experimental results show that the algorithm has a good neutral-point voltage balancing effect.