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Single Phase Detection of Voltage Sag Based on Instantaneous Reactive Power Theory

Voltage sag is one of the most frequent and serious dynamic problems that impact the power quality. To solve this problem, fast and precise detection of the voltage sag is needed. A detection method is presented in this paper, using single phase voltage information, to be applied in the typical condition of unsymmetrical three-phase voltage sag. This method adopts fast recognition of voltage disturbance and SPLL. Finally, MATLAB simulation has been used to verify the effectiveness of the method.