3D-SVM Method for Controlling Zero-Sequence Component in Three-Phase Four-Wire Three-Level Inverters

Three-phase, four-wire, three-level inverters may experience high zero-sequence current in neutral wire, due to mechanical delays in switching devices, and load or system imbalances in microgrids. The neutral current not only causes line losses but also affect the stability of the power system. Therefore, this paper proposes a 3D-SVM modulation method applied to three-phase, four-wire, three-level inverters. The full vector space of the three-phase, four-wire, three-level inverters is reasonably divided in three dimensions according to the nearest vector principle. Compared to traditional SVM, the proposed method controls the zero-sequence current from a modulation perspective, possessing the ability to regulate the zero-sequence component. Simulation and experimental results demonstrate the effectiveness of the proposed modulation method in controlling zero-sequence current.