Abstract:Neutral-point-clamped three-level inverter has many advantages compared with the traditional two-level inverter, which have make it widely used in high-voltage and high-power applications. But the special topology also has inherent problem about neutral-point voltage imbalance. On the basis of space vector pulse width modulation (SVPWM), a neutral-point charge prediction control strategy based on the combination of balance-factor and vectors-selection is proposed. during the modulation, neutral point charge can be eliminated according to the balance-factor. but when the balance-factor exceeds it’s limit, the fluctuation of neutral voltage can be further restrained by vectors-selection. Finally the MATLAB simulation model was established and studied, the simulation results of which proved it’s effectiveness.