Power quality improvement using a Three Dimensional Space Vector Modulation with SRF theory for three level neutral point clamped four leg shunt active power filter controlling in dq0 axes

In this paper, a Three level NPC four leg inverter is used as a shunt active power filter (SAPF), and the Three level Three Dimensional Space Vector Modulation technique in the aso axes (3-level 3D SVM) for generate the switching signals of this SAPF for power quality improvements under balanced and unbalanced loads are proposed. In order to, improved the output voltage forms, lower switching losses, fix switching frequency, minimizing the harmonics of source currents, reducing the magnitude of neutral current, eliminating the zero-sequence current, and to compensating the reactive power in the four-wire distribution network, and for a good dynamic the synchronous reference frame (SRF) theory in the dq0-axes for generate and extract the reference currents which should be injected by Three level NPC four leg inverter is presented. Simulation results of three level Shunt Active Power Filter performances are presented to validate the proposed three level 3D-SVM with SRF theory for switching signals and reference signals generating.