Comparative Analysis on Current Control Methods of Shunt Active Power Filter for the Improvement of Grid Energy Quality

Active filtering has been known as a promising solution for the compensation of reactive currents and harmonics in the grid energy quality. This paper presents the study and comparison of two control strategies applied to a three-phase Shunt Active Power Filter (SAPF). It is about the direct and indirect current control (DCC and ICC). A simulation model of SAPF is prepared in the Matlab/Simulink environment. The operation of the proposed system is improved by the inclusion of a PI controller for the regulation of DC bus voltage Vdc, and a Hysteresis current controller for the generation of switching pulses for the SAPF. The direct current control is based on the extraction of harmonic components by using the instantaneous active and reactive power theory (p-q) while the indirect current control consists in imposing the sinusoidal form on the source side currents. The dynamic performances and robustness of the two control strategies are evaluated by using of two nonlinear loads switched at different times.