Evaluation method for paper oil insulation aging state through characteristic parameters based on time domain dielectric response

Abstract

The invention discloses an evaluation method for a paper oil insulation aging state through characteristic parameters based on time domain dielectric response. The evaluation method for the paper oil insulation aging state through the characteristic parameters based on the time domain dielectric response comprises the steps of measuring a polarization and depolarization current of a system, simulating an equivalent circuit of the polarization and depolarization current, calculating circuit parameters of an equivalent circuit model to obtain a depolarization current, smoothing the depolarization current and fitting the depolarization current to obtain depolarization power quantity, building a function relationship of aging time and characteristic parameters of the depolarization power quantity, integrating the relationship between the polymerization degree changing rule and the characteristic parameters of the depolarization power quantity through combining a first order dynamical model of a polymerization degree changing rule of mineral paper oil insulation acceleration thermal aging. By the utilization of the evaluation method for the paper oil insulation aging state through the characteristic parameters based on the time domain dielectric response, the operation is simple, sensitivity is high, and the evaluation method for the paper oil insulation aging state through the characteristic parameters based on the time domain dielectric response is suitable for the use of engineering.

Description

technical field [0001] The invention relates to the technical field of power transmission detection, in particular to a method for evaluating the aging state of oil-paper insulation based on characteristic parameters of time-domain dielectric response. Background technique [0002] Converter transformer is one of the important equipment in UHVDC transmission system, and its operation reliability directly affects the safe operation of the whole system. A serious accident of a converter transformer will not only cause its own damage, but also interrupt the power supply, resulting in huge economic losses. In addition to AC voltage, lightning impulse and operating overvoltage, the running converter transformer also bears the effects of DC, AC superimposed DC and polarity reversal voltage. Under the action of these voltages, the distribution of the electric field inside the transformer, the breakdown characteristics of insulating materials, the accumulation and distribution of s...

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Problems solved by technology

There is no in-depth research report on the influence of the properties of insulating oil and insulating paper on the formation and migration of space charges during the aging process of oil-paper insulating media.

As an aging product of oil-paper insulation and directly endangering the insulation performance of transformer oil-paper, there is no research report on how moisture will affect the space charge of oil-paper media.

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