Oscillation type lightning impulse test system and method based on transformer self-sensing

Abstract

The invention discloses an oscillation type lightning impulse test system and method based on transformer self-sensing. An oscillation type lightning impulse voltage generator is adopted to apply an impulse signal to a high-voltage winding of a to-be-tested power transformer. The voltage waveform of the high-voltage side is measured through a capacitive voltage divider. The secondary end screen ofa high-voltage side tested-phase sleeve is used as a self-sensing capacitive voltage divider of the to-be-tested power transformer. A leakage current signal of the sleeve and a partial discharge current signal in the sleeve can be transmitted out. The iron core of the to-be-tested power transformer serves as a transformer self-sensing sensor. An ultrahigh-frequency signal generated by internal discharge is transmitted to an intelligent expert diagnosis system through a grounding wire to judge whether the to-be-detected power transformer has defects or not. The technical problems of large equipment size, low voltage generation efficiency and inconvenience in field debugging of a generator for generating a double-index impulse voltage due to the fact that a double-index impulse voltage is adopted in an impulse withstand voltage test of an existing power transformer are solved.

Description

[0001] This application claims the priority of the Chinese patent application with the application date of December 27, 2019 and the application number 201911380598.0 technical field [0002] The present application relates to the technical field of electric power testing, and in particular to an oscillation-type lightning impulse testing system and method based on transformer self-sensing. Background technique [0003] The power transformer is the core component of the power system and the key to ensure the reliable and safe operation of the power grid. When the power system is subjected to lightning strikes, lightning atmospheric overvoltages will be generated. The amplitude and steepness of the lightning impulse overvoltages are much higher than the amplitude of the power frequency withstand voltage. Discharge or breakdown of unexposed insulation defects endangers the safety of transformers and power systems. In order to check the potential safety hazards of the transfor...

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Problems solved by technology

[0004] The embodiment of the present application provides an oscillating lightning impulse test system and method based on transformer self-sensing, which is used to solve the problem that the existing power transformer uses a double-exponential impulse voltage for the impulse withstand voltage test, and there is a generator that generates a double-exponential impulse voltage. The technical problems of large equipment volume, low voltage generation efficiency and inconvenient on-site debugging

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