Online testing method for aging of transformer insulating oil based on electric field induction

Abstract

The invention discloses an online testing method for aging of transformer insulating oil based on electric field induction. The online testing method comprises the following steps of: firstly, arranging a pair of detection pole plates into the transformer insulating oil; then, acquiring inductive charges of the detection pole plates in an alternating electric field in a transformer, charging an energy-storage capacitor through inductive charges by a charge pump, counting quantities of the inductive charges of the detection pole plates by the time required by the charging of the energy-storage capacitor, and counting an actual dielectric constant of transformer oil; finally, judging that whether a difference between the actual dielectric constant of transformer oil and a normal dielectric constant of transformer oil exceeds a preset threshold value, if the difference does not exceed the preset threshold value, releasing electric energy on the energy-storage capacitor and returning, and if the difference exceeds the preset threshold value, determining that the transformer oil is aged. According to the online testing method for the aging of the transformer insulating oil based on the electric field induction, the inductive charges are detected by the detection pole plates arranged in the transformer insulating oil, thus the dielectric constant of medium (transformer oil) between the pole plates is reflected, and then a result whether the transformer oil is aged is reflected. The method is based on the electric field induction, so that the method is simple, the online detection is quickly realized, and a power supply doe not need to be provided to a sensor.

Description

technical field [0001] The invention relates to the technical field of transformer aging state detection, in particular to an on-line detection method for transformer insulating oil aging based on electric field induction. Background technique [0002] The existing detection methods for the aging of transformer insulating oil mainly include chemical methods and electrical methods. Chemical methods mainly include dissolved gas analysis in oil, liquid chromatography analysis, etc.; electrical detection methods include measuring oil dielectric loss factor, dielectric constant, and partial discharge detection. Most of the current detection devices are off-line or the method is complicated, and it is necessary to provide DC or AC power to various sensors. (Wang Songlin, "Transformer Insulation Aging Diagnosis Technology", "Transformer", No. 8, 2011; Hao Jian et al., "Evaluation of Transformer Oil-paper Insulation Aging State Using Frequency-Domain Dielectric Spectroscopy", "Powe...

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Problems solved by technology

Most of the current detection devices are off-line or the method is complicated, and it is necessary to provide DC or AC power for various sensors

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