Abstract: The traditional NPC topology is affected by the voltage imbalance at the DC neutral point,which not only leads to the system instability,but also affects the ratings of capacitors and semiconductor devices,and increases the total power loss.Based on this,this paper proposes a novel converter topology and its control strategy,which are suitable for the AC-DC converter link of the microgrid with DC distributed power supply or the AC-DC microgrid. The proposed converter is a neutral point clamped（NPC）H-bridge. In order to solve the problem of capacitive voltage balance of the DC port of the NPC-based converter,a DC port voltage balance method based on space vector PWM is proposed to balance the neutral voltage. This method fully considers the harmonic effect of output voltage and switching loss, and defines the applied vector sequence.Finally,the simulation comparison with the traditional converter is carried out to verify the advantages of switching loss of the converter under balanced and unbalanced loads. In addition,experiments are carried out to verify the effectiveness and superiority of the proposed voltage balancing method.