αβ-Transformation Based Algorithm for Identifying the Power Quality Events in an Electric Distribution Network

αβ-Transformation is a dc transformation used to transfer the three-phase ac system of voltage or current to a dc system. This paper presents the application of this transformation to identifying the power quality events, such as harmonics, voltage sage, voltage flicker, voltage swell and voltage transients. This transformation can be implemented for a single phase or three- phase system of voltage. The phasor voltage resulting from the combination of Vα and Vβ has a magnitude that proportional to the system operating voltage and rotates with a speed of the frequency of the system voltage.