Lightning stroke overvoltage identification method based on overvoltage waveform characteristics

Abstract

The invention discloses a lightning stroke overvoltage identification method based on overvoltage waveform characteristics, and relates to the technical field of electric power. Correlation analysis of transient overvoltage waveforms of different lightning stroke overvoltage and general short-circuit fault overvoltage is carried out, inductive lightning stroke interference signals are distinguished from direct lightning stroke line fault signals according to the minimum similarity coefficient and the average similarity coefficient among the four lightning stroke overvoltage waveforms, and due to the fact that an inductive lightning stroke overvoltage wave head is generally positive, and a direct lightning stroke overvoltage wave head is generally negative, the difference between the polarities of the wave heads of the inductive thunder and the direct lightning is used as an auxiliary criterion, the reliability of the identification criterion is improved, inductive lightning stroke faults and direct lightning stroke tower fault signals are identified, lightning stroke interference of the distribution line and various lightning stroke faults are identified by using the similarity coefficient between overvoltage waveforms, and a very good identification effect is achieved; and the method is suitable for large-scale popularization and application.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a lightning strike overvoltage identification method based on overvoltage waveform characteristics. Background technique [0002] It is known that in the research of power system signal processing, correlation analysis is mainly used in research fields such as power quality analysis, motor fault diagnosis, and fault line selection. When the distribution line is subjected to induction lightning, an overvoltage of similar magnitude, similar waveform, and same polarity will be induced on the three-phase line, and the overvoltage waveform is a positive wave. The amplitude of the lightning fault overvoltage waveform becomes smaller, and the similarity between the three-phase voltages decreases, especially the voltage waveform difference between the fault phase and the sound phase is relatively large; if a direct line fault occurs, the lightning strike line overvoltage will sho...

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Problems solved by technology

When the distribution line is subjected to induction lightning, an overvoltage of similar magnitude, similar waveform, and same polarity will be induced on the three-phase line, and the overvoltage waveform is a positive wave. The amplitude of the lightning fault overvoltage waveform becomes smaller, and the similarity between the three-phase voltages decreases, especially the voltage waveform difference between the fault phase and the healthy phase is relatively large; It has the characteristics of large amplitude, large wave head steepness, and large difference in three-phase voltage, and the largest overvoltage waveform is a negative wave. Compared with the lightning strike line overvoltage, the wave head steepness of the lightning strike tower overvoltage is slightly slower, The high-frequency oscillation intensity is low, the difference between the three-phase voltages is small, and the trend of change is roughly the same, but the voltage waveform characteristics of the faulty phase and the healthy phase are still quite different, etc.

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