A device for testing the correlation between micro-water distribution and dielectric response of oil-paper insulation

Abstract

The invention discloses a device for detecting correlation between paper oil insulation micro-water distribution and dielectric response. The device comprises a constant temperature tank, an oil storage tank, a micro-water testing sensor, a dielectric response tester, a microcomputer system, a humidifier, insulation paper and a plurality of electrodes. The oil storage tank is divided into two parts by the insulation paper and a seal ring; the concentration of micro-water dissolved in oil on the two sides of the insulation paper is controlled by connecting / disconnecting a power supply of the humidifier, so that the micro-water in the insulation paper is in stable gradient distribution; and the dielectric response is tested by a special instrument and the dielectric response result is recorded. The device is capable of testing the correlation between the paper oil insulation micro-water distribution and the dielectric response at high efficiency and has good repeatability.

Description

technical field [0001] The invention relates to a device for testing the correlation between micro-water distribution and dielectric response of oil-paper insulation. The technology is used to study the relationship between micro-water distribution characteristics and dielectric response in oil-paper insulation of large-scale oil-immersed transformers and other power equipment, and belongs to oil-paper insulation. Insulation dielectric response test field. Background technique [0002] Oil-immersed transformers have always been the main choice for large-scale transformers. Moisture in the insulating paper will seriously affect its electrical and mechanical life. How to accurately evaluate the state of micro-moisture in the insulating paper of transformers put into operation has always been a difficult problem that has been widely concerned in the industry. [0003] The evaluation of the moisture state of transformer insulating paper is divided into non-electrical measurement...

AI Technical Summary

Problems solved by technology

There are two major disadvantages in the traditional method: ①The test needs to apply high voltage, which may lead to insulation damage; ②These tests are limited to a single piece of information, providing very little insulation information, and there are many interference factors, so it is impossible to establish micro-water insulation of transformer oil-paper insulation. Correspondence between status and test results

[0004] However, in practical applications, large errors often occur when evaluating transformer oil-paper insulation micro-water by the dielectric response method. In addition to the existence of bushing leakage current, electromagnetic interference and other factors, more importantly, for transformers operating on site, due to dynamic changes in load and Due to the influence of ambient temperature and other influences, the micro-water in the oil-paper insulation is in an unbalanced state for a long time, and this phenomenon is more prominent for transformers under certain special working conditions, such as traction transformers in electrified railways, because the load density changes greatly with time It is a normal working condition that the short-term load current exceeds 2 times or even 3 times the rated load. The micro-water in the oil-paper insulation is generally in an extremely unbalanced state. This unbalanced state makes the distribution of the micro-water in the insulating paper very uneven with the thickness Uniform, uneven distribution of micro-water will seriously affect the evaluation results; in order to study this effect, at present, the micro-water diffusion model is mainly used to calculate the dynamic distribution of micro-water in oil-paper insulation while testing the dielectric response. The disadvantages are: 1) During the whole process, the concentration of micro-water in the insulating paper is changing, which has a great impact on the test and analysis; 2) Since the concentration of micro-water in various places has been changing, the repeatability of the experiment is poor

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