Research on Oscillation Suppression Methods in Shunt Active Power Filter System

The shunt active power filter (SAPF) system oscillation is a massive threat to the security and stability of grid. This study classifies SAPF into two categories according difference in mechanisms. one category caused by resonant characteristics switching noise called external loop amplification. other induced presence capacitor load current for self-excited oscillation. Unlike previous studies, this tried reveal internal relationship between kinds oscillation, present general virtual-damping-based suppression strategy covering damping method, provide discrete domain criterion control system. sampling frequency was at least six times frequency. region enlarged with an increase narrowed rise As harmful problem, proposes composite combining selective harmonic compensation grid-side feedback. Moreover, considers more resistance–inductance–capacitance situations analyzes SAPF–Thyristor Switched Capacitor (TSC) hybrid Simulations experiments demonstrated that proposed compound method can reduce primary harmonics than 90% has better performance methods. In particular, if we selected TSC series reactance rate following 6%, could usually be avoided.