Fast and accurate voltage sag detection algorithm

Voltage sags may affect the accurate operation of several equipment connected to power systems. A typical example is the doubly-fed induction generator (DFIG), which is often employed in wind energy conversion systems (WECSs). Since the stator windings are directly connected to the power grid, the generator becomes very sensitive to such power quality disturbances. In this context, this work proposes a fast and accurate algorithm for the detection of voltage sags based on the aggregate value concept. The algorithm allows detecting both symmetrical and asymmetrical single-phase, two-phase, and three-phase events even when the supply voltage is distorted. Experimental results are presented to demonstrate that this algorithm can be considered as a good option for practical applications.