Analysis of reference current identification strategies for shunt active filter under distorted load conditions

Due to the increasing use of the nonlinear loads, shunt active filters have gained a lot of attention as an effective solution for harmonic current mitigation. One of the most important units in the shunt active filter is the reference current identification unit, because of its direct impact on the filter efficiency, it has been discussed in many researches and several theories are developed for the purpose of extracting the reference currents effectively. This paper examines the performance of two reference current identification strategies, namely, the synchronous reference frame or (SRF theory) and the instantaneous reactive power or (PQ theory) applied to a shunt active power filter under an unbalanced voltage conditions and a nonlinear load.