This paper presents a simple three-dimensional space vector modulation method in gh𝜸 coordinates for a three-level four-leg neutral-point-clamped inverter. The idea uses redundant vectors as centre points to establish two-level space vector diagrams simplifying the original space, the first sector of which is designated as subspaces, where a modulation process is implemented. The duty cycle and all possible switching sequences in a tetrahedron can be calculated automatically without manual storage and can avoid a full-scale search process. Additionally, the neutral point potential can be balanced by three types of charge through cancellation. Such features enable the inverter to demonstrate good performance under closed-loop control. Moreover, the proposed method can be applied to a multilevel inverter. Simulation and experimental results demonstrate the effectiveness of the proposed concept.