Method for monitoring sudden rising or falling of voltage and monitoring device applying method

Abstract

The invention discloses a method for monitoring sudden rising or falling of voltage. The method comprises the following steps of: acquiring primary signal voltage; processing the primary signal voltage, namely determining a voltage suddenly-rising event or a voltage suddenly-falling event by calculating the root mean square value of the primary signal voltage and outputting the starting time point estimate and the finishing time point estimate of the determined event; performing wavelet decomposition on the primary signal voltage to obtain a wavelet coefficient; performing shrinking transformation on the wavelet coefficient; reconstructing the wavelet coefficient subjected to shrinking transformation; and thus obtaining accurate values of the event starting time point and event finishing time point of the primary signal voltage. The invention also provides a monitoring device applying the method for monitoring sudden rising or falling of voltage. The method and the device provided by the invention have high accuracy and are easy to operate.

Description

technical field [0001] The invention relates to a voltage swell or sag monitoring method and a monitoring device using the method, in particular to a voltage swell or sag monitoring method suitable for three-phase AC circuits and a power monitoring device using the method. Background technique [0002] In the electricity market environment, the power quality problem has been paid more and more attention by people. As the main problem of modern power quality, voltage swell / sag has been considered as one of the most important power quality problems affecting the normal and safe operation of many electrical equipment. The huge economic loss caused by voltage swell / sag has been widely concerned in the world, especially in developed countries. In order to minimize the harm of voltage swell / sag, the primary problem is to have a fast, accurate and effective method to monitor the characteristic quantity of the voltage swell / sag signal. [0003] Existing monitoring methods of chara...

AI Technical Summary

Problems solved by technology

Since the execution of the monitoring method depends largely on the mathematical analysis model, and the execution of the method and / or the control parameters of the algorithm convergence speed need to be judged based on the engineering experience of the operator, the implementation is very complicated

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