Shunt Active Power Filter Based On Three Level Four Leg Inverter Controlled By Three-Level Three Dimensional Space Vector Modulation Based On The Redundant Voltages Vectors Technique

摘要

In this paper, we study the unbalanced of the dc bus voltages of three level four leg Neutral Point Clamping (NPC) Shunt Active Power Filter (SAPF). This SAPF is applied for improving the power quality in three-phase four-wire distribution system by compensation of harmonic currents and reactive power produced by a single phase nonlinear loads. In the first part, we present a topology of three-level four leg NPC Inverter, and its three dimensional space vector diagram. In the second part, as solution for unbalanced of the input dc bus capacitor voltages and to fixed the switching frequency of switches of the three-level four leg NPC SAPF, we propose the balancing three-level three dimensional space vector modulation with neutral point voltage control which based on the redundant voltages vectors. After that, the efficiency of the proposed balanced three-level 3D SVM technique for controlling me three level four leg Neutral Point Clamping (NPC) SAPF is demonstrated through simulation using Sim-power-system and S-Function integrated in Matlab simulink. The proposed balanced three-level 3D SVM technique is compared with classical three-level 3D SVM technique. The simulation results also show that the strategy of balanced three-level 3D SVM technique clearly improves the three-level four leg Neutral Point Clamping (NPC) Shunt Active Power Filter operation in terms of robustness, stabilization, the exceeding and balanced of the DC voltages, switching frequency and THDs compared to the classical three-level 3D SVM technique.