An on-load tap-changer mechanical state monitoring method and system based on a multi-layer filter

Abstract

The invention provides an on-load tap-changer mechanical state monitoring method and system based on a multi-layer filter. The method comprises the steps of: acquiring vibration signals in a switchingprocess of an on-load tap-changer; performing normalization processing on the vibration signals; performing discrete Fourier transform on the vibration signals subjected to normalization to obtain frequency spectrum distribution of the vibration signals; determining a quality factor according to the frequency spectrum distribution and designing a multi-layer filter; inputting the frequency spectrum distribution to the multi-layer filter to obtain a plurality of sub-band signals to form a sub-band signal matrix; calculating a covariance matrix of the sub-band signal matrix according to columnsand the modulus maximum of the covariance matrix; calculating the statistical magnitude of the modulus maximum and the control limit of the statistical magnitude; judging the mechanical state of theon-load tap-changer according to the statistical magnitude. The method and the system can diagnose the mechanical work state of a tap-changer of a transformer and can detect whether the mechanical state of a tap-changer of a transformer changes effectively and accurately, so that effective measures can be adopted for a tap-changer timely.

Description

technical field [0001] The invention relates to the field of monitoring the mechanical state of a tap changer, in particular to a method and system for monitoring the mechanical state of a transformer on-load tap changer based on a multilayer filter. Background technique [0002] The transformer is one of the most important equipment in the power system, and its operation stability has a great influence on the safety of the power system. The on-load tap-changer is the only movable part of the transformer, which can change the voltage transformation ratio under the load condition, realize the adjustment of the system voltage under the condition of uninterrupted power supply, realize the compensation of voltage fluctuation, adjust the power, improve the system performance and improve the electric energy Important features such as quality. However, with the increase of tap changer voltage adjustment times, its failure rate also increases. The faults of on-load tap-changers ma...

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Problems solved by technology

[0004] However, considering the complexity of the mechanical structure of the transformer tap changer and the existence of unavoidable interference signals in the field operation environment, how to extract reasonable and effective characteristic indicators from the vibration signal during the tap changer switching process, and then realize the tap changer Accurate monitoring of switch mechanical status has always been a research difficulty

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