Control design of a neutral point clamped converter based active power filter for the selective harmonic compensation

This paper presents the control of an active power filter (APF) based on a 3-phase, 3-level neutral point clamped (NPC) converter with selective harmonic compensation. To achieve the selective harmonic compensation, the APF use several synchronous rotatory frames, which are rotating at the angular frequency and sequence of their respective harmonics, to detect and control the magnitude and angle of each individual harmonic using d and q variables. A three dimensional space vector modulator (3D-SVPWM) is used to generate the compensation currents. Due to its multilevel topology, the proposed active power filter can be used in high voltage power quality applications, such as sub-transmission and distribution levels. Simulation results are shown to validate the proposed solution and corroborate the proper function of the multilevel active power filter.