For the complex structure of traditional multi-level inverters, a hybrid four-level three-phase three-leg voltage source inverters and neutral-point potential control method are proposed. This method realizes the same output line voltage level as traditional five-level inverters by adjusting the voltage of the divided capacitor to 1:2:1 ratio in DC-side and utilizing the voltage difference between phases. Compared with traditional NPC five-level inverters, this structure needs fewer switching devices and has higher economic efficiency. The neutral-point potential control method proposed for the topology can balance the DC-side capacitor voltage. The correctness and validity of the proposed topology and neutral-point potential control method are verified by MATLAB/Simulink simulation under the given conditions.
