389 A New Method to Detect Voltage Sag Duration Based on Information-Entropy

Using information-entropy to detect and locate the starting and ending times of the voltage sag, and then the voltage sag duration can be calculated. Adaptability of the method is analyzed in conditions of different dropping amplitudes and harmonic waves and white noise, the mathematical morphology filter is introduced to preprocess the voltage sag signal with containing white noise. Use the Matlab software environment to prove the feasibility of the mothed proposed, the simulation result shows that this method is not only simple in principle, but also has higher accuracy in detection, and this method has strong adaptability.