Anti-interference online monitoring method for partial discharge of high-voltage transformer bushing

Abstract

The invention relates to an anti-interference online monitoring method for partial discharge of a high-voltage transformer bushing. A high-frequency current sensor is additionally arranged at a grounding wire of an iron core of a transformer besides a grounding high-frequency current sensor of an end screen of the transformer, two paths of signals can be synchronously acquired by the system, and through a time domain comparison algorithm of the two paths of signals, the partial discharge signal of the transformer can be effectively filtered, only the partial discharge signal of the bushing is reserved, and the purpose of monitoring the partial discharge of the high-voltage transformer bushing is achieved.

Description

technical field [0001] The invention belongs to the technical field of insulation monitoring of large-scale high-voltage transformer bushings, and in particular relates to an online partial discharge monitoring method of high-voltage transformer bushings. Background technique [0002] Transformers play an extremely important role in the process of power transmission. Transformers of different voltage levels can be combined to connect power grids of different voltages to form a complex and huge power network, so that power energy can be transmitted over long distances. The bushing of the transformer is the most important part of the inlet and outlet interface of the transformer busbar, and its performance will directly affect the normal operation of the transformer. [0003] At present, the testing of high-voltage transformer bushings is still mainly in the offline detection stage, that is, in the case of transformer power outage maintenance, the routine detection test of hig...

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Problems solved by technology

The first two methods are mainly to monitor the partial discharge of the transformer body, not the partial discharge of the transformer bushing; the third method is to use ultrasonic and ground wave sensors to couple the partial discharge signal of the bushing at the bushing riser seat. The disadvantages of this method are Quantitative measurement of partial discharge cannot be carried out, only qualitative measurement, and the transformer is greatly affected by its own vibration during operation, resulting in inaccurate measurement; the fourth method is the ultra-high frequency method, and the disadvantage is that the transformer bushing is an external The built-in equipment is completely exposed to the outside world, so it is easily interfered by high-frequency electromagnetic waves such as external mobile phones and base stations, resulting in large measurement errors

Therefore, it is currently not possible to detect an accurate transformer bushing PD signal

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