Discharge capacity monitoring and collecting method, device and system for ultrahigh frequency local discharge

Abstract

The invention discloses a discharge capacity monitoring and collecting method for ultrahigh frequency local discharge, In the method, the pulse number exceeding the comparative level in each phase interval of an industrial frequency period is obtained through level comparison by analyzing the characteristic of an ultrahigh frequency local discharge signal and scanning a comparative level and the local discharge signal; the pulse number of different comparative levels is obtained through gradually increasing the comparative level, if no comparative pulse is output, the local discharge amplitude is smaller than the set comparative level, thus, a three-dimensional spectrogram of the ultrahigh frequency local discharge signal can be obtained through the pulse numerical values under different comparative levels; and conventional high-speed large-capacity data acquisition is changed into high-frequency pulse comparison counting, thereby simplifying an ultrahigh frequency local discharge monitoring circuit. A device provided by the invention has wide use range, higher accuracy, simple structure, smaller size, low cost, simple operation and convenient carry.

Description

technical field [0001] The invention relates to the field of insulation monitoring of high-voltage electrical appliances, in particular to an ultra-high-frequency partial discharge discharge monitoring and acquisition method, and also relates to an ultra-high-frequency partial discharge discharge monitoring and acquisition device and system. Background technique [0002] There are often some defects inside the insulation of electrical equipment, for example, air gaps or bubbles are prone to appear in some pouring, extruded or layer-wound insulations. The breakdown field strength and dielectric constant of air are smaller than those of solid media, so these air gaps or bubbles discharge first under the action of applied voltage. In addition, this is the partial discharge of bubbles in electrical equipment. In addition, such as oil-immersed transformers The insulation structure is mainly composed of oil, paper, cardboard and some other solid insulation materials. Due to the di...

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Problems solved by technology

[0006]The existing UHF signal acquisition method is to collect the overall waveform of the partial discharge signal, and then analyze and calculate, and the cost of the equipment is quite expensive

Since the frequency range measured by the UHF method is 300MHz to 3GHz, the equipment is required to be equipped with a high-frequency A/D converter, the signal transmission is centralized, and a large amount of high-speed storage is required, which makes the entire equipment expensive; and the equipment processes a large amount of data during operation. , the processing time is long, which affects the next step of the detection; because it needs to be avoided and the fixed installation is not easy to carry

Since the device works outdoors for a long time, it is affected by the atmospheric environment such as temperature and humidity, which will also cause deviations in the measurement data

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