Voltage sag source identification method based on mutual approximation entropy

Abstract

The invention discloses a voltage sag source identification method based on mutual approximation entropy. The method comprises the steps of: (1) establishing a sample waveform library; (2) performingdata preprocessing; (3) calculating mutual approximate entropy values of a waveform to be matched and the sample waveform, and retaining the minimum entropy value therein and the information of the corresponding sample; and (4) performing sag source type identification: determining whether the minimum entropy value is in a threshold range or not, if not, determining that a pending result is reliable, namely, the waveform to be matched being the sag source type, or else, determining that the waveform to be matched does not belong to any one sag source type in the waveform library. The voltage sag source identification method has high accuracy at the aspect of actually measured waveform identification of the voltage sag source, is short in the required sampling window and simple and easy toimplement the algorithm, help engineers with correct determination of the voltage sag source types and the generation reasons to a certain extent to provide targeted theoretical guidance for treatmentof the voltage sag source problem, and has great application value and prospects.

Description

technical field [0001] The invention relates to a power quality disturbance source identification method, in particular to a voltage sag source identification method based on mutual approximate entropy. Background technique [0002] With the increasing level of industrial equipment, building electrical automation and intelligence, the impact of voltage sag on the production and operation of large industrial and commercial users is becoming more and more significant, especially in semiconductor manufacturing, precision instrument processing, and automobile manufacturing. The electronic equipment industry is very sensitive to voltage sags. When the effective value of the voltage is lower than 90% and the duration reaches 1 to 2 cycles, it will trip and stop. Voltage sag is a common power quality problem. Motor starting, transformer switching, short-circuit faults, etc. will cause voltage sag. Production interruption and delay caused by voltage sag interference are on the rise....

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Problems solved by technology

[0005] Purpose of the invention: Aiming at the deficiencies in current research on voltage sag source identification, the purpose of this invention is to provide a voltage sag source identification method based on mutual approximation entropy to effectively avoid problems such as difficult convergence and overly complex algorithms in traditional methods

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