Sensor for monitoring noise of oil-immersed transformer

Abstract

The invention provides a sensor for monitoring the noise of an oil-immersed transformer. The sensor herein includes a piezoelectric ceramic tube which is fastened by a fastening rack and a sleeve, andan insulating pad which are disposed between the piezoelectric ceramic tube and the fastening rack as well as the sleeve; the piezoelectric ceramic tube, the fastening rack and the sleeve are packaged with a material which can resist high temperature and transformer oil; and the sleeve is provided with a thermal resistor therein. According to the invention, an acoustic sensor can remain stable ina transformer oil, can resist the high temperature which is generated in the operation of an oil-immersed transformer. The built-in thermal resistor can measure the working temperature of the acoustic sensor, and the sensitivity corresponding to the working temperature can be configured, such that the acoustic sensor can work normally in an oil liquid of the oil-immersed transformer. The sound pressure signal that is measured is conductive to the analysis of the mechanism of noise generation and dissipation inside the oil-immersed transformer, and can help to perform real-time monitoring on the performances of the oil-immersed transformer.

Description

technical field [0001] The invention relates to the technical field of transformer on-line monitoring, in particular to a sensor for monitoring the noise of an oil-immersed transformer. Background technique [0002] The body noise of the oil-immersed transformer mainly comes from the vibration of the iron core, winding and other structures. Therefore, when a fault such as winding deformation or looseness occurs inside the oil-immersed transformer, its body noise will change significantly. Therefore, based on the transformer body noise On-line Monitoring has great application potential. [0003] In terms of transformer noise detection, the current common method is to place a microphone outside the transformer, or install a vibration sensor on the surface of the oil-immersed transformer box, and use the measured signal to reverse the noise and vibration inside the oil-immersed transformer. Such inversion mainly relies on mathematical models, so its accuracy is difficult to gu...

AI Technical Summary

Problems solved by technology

[0004] However, common acoustic sensors (such as microphones and hydrophones) are mainly used in air and water, and most of them cannot be directly applied in transformer oil

For example, the polarized film of a common condenser microphone can be corroded by impurities (such as sulfides) contained in transformer oil; and the rubber packaging material (such as neoprene) commonly used in hydrophones will swell in transformer oil , resulting in sensor failure or changes in performance

Images