A 3D-SVM Algorithm for Three-Phase Four-Leg Four-Wire Three-Level Inverter

Aiming at the application of a three-phase four-leg four-wire three-level(3P4L4W 3L)inverter with the fourth bridge leg configured as two levels under unbalanced or nonlinear loads, a three-dimensional space vector modulation (3D-SVM) algorithm is proposed. In this article, the equivalent switch model of the topology is analyzed, mapped into three-dimensional space through α-β-γ coordinate transformation. The vector synthesis methods for arbitrary tetrahedron blocks are systematically discussed. This modulation method meets the modulation requirements and achieves output voltage clamping on the power supply side under specific conditions, reducing switch losses. Simulation results verify the theoretical analysis and proposed design.