The ability to individually extract the many disturbances of the AC line currents or voltages is desirable for reference signal calculation algorithms employed in power conditioners, allowing improved utilization of the power converter. This paper proposes a novel algorithm based on the dot product of three dimensional space vectors in the abc coordinate system, for real time calculation of the instantaneous positive, negative and zero sequence components for each individual harmonic. It is presented the functionalities for compensating fundamental reactive power, selected current harmonics and current unbalances. This method is computationally simple and requires no coordinate transformation. The proposed algorithms are validated by simulation and experiments.Keywords-Amplitude and phase estimation, phase locked loops (PLL), power quality, space vectors.