Observer based reference current generation for a three-phase shunt active power filter

In this paper, a new observer-based method, which generates the current reference for a three-phase shunt active power filter (SAPF), is presented. This technique is useful for active power filters and capable to eliminate harmonics and compensate reactive power simultaneously. First, the fundamental active current to identify is modeled in the form of a generating process. The other harmonic components appearing in the load current, as well as the basic noises inherent with the signal measurements, are all considered as noises for the observer. The goal of the extraction consists in filtering the noise in order to recover the active fundamental current. The filtering is carried out using an observer on the generating model. The dynamics of the extraction will depend on the speed of convergence of the observer. Simulation results are presented, showing that the method is feasible and the results are acceptable.