An electromagnetic voltage transformer primary winding tail end insulation detection method and device

Abstract

The invention discloses a method and a device for testing tail end insulation of a primary winding of an electromagnetic voltage transformer, and aims to accurately and rapidly detect the insulation state of the tail end of a primary winding of an electromagnetic voltage transformer under a condition of electrification, achieve potential fault detection and detect the insulation state of the tailend of the primary winding according to zero sequence voltage variations caused when a vee connection winding of the electromagnetic voltage transformer is in short circuit. Short circuit switches areconnected with two ends of the vee connection winding of the electromagnetic voltage transformer, a waveform acquisition module is connected with a measuring or metering winding of the electromagnetic voltage transformer, the short circuit switches are controlled to be closed for a certain time and then cut off, at the same time three-phase voltage waveforms of the measuring or metering winding are acquired by using the waveform acquisition module and are combined to form zero sequence voltage waveforms, and the insulation state of the tail end of the primary winding connected with a harmonicwave eliminator, of the electromagnetic voltage transformer, is judged according to zero sequence voltages of the closed short circuit switches and the fluctuation situations of the zero sequence voltages of the closed short circuit switches.

Description

technical field [0001] The application specifically relates to a method and device for detecting insulation at the tail end of a primary winding of an electromagnetic voltage transformer, which is applicable to the technical field of live detection and on-line monitoring of the insulation state of the tail end after the electromagnetic voltage transformer is equipped with a primary resonance eliminator. Background technique [0002] In order to prevent ferromagnetic resonance, the electromagnetic voltage transformer for graded insulation is equipped with a silicon carbide resonance eliminator at the end of the primary winding. Under recovery, lightning strike and operating conditions, voltage will appear on the silicon carbide resonance eliminator, which will cause the voltage at the end of the primary winding of the electromagnetic voltage transformer to increase. [0003] Because the ungrounded system uses a primary silicon carbide resonance eliminator to protect the ferro...

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Problems solved by technology

[0002] In order to prevent ferromagnetic resonance, the electromagnetic voltage transformer for graded insulation is equipped with a silicon carbide resonance eliminator at the end of the primary winding. Under recovery, lightning strike and operating conditions, voltage will appear on the silicon carbide resonance eliminator, resulting in an increase in the voltage at the end of the primary winding of the electromagnetic voltage transformer

[0003] Because the ungrounded system uses a primary silicon carbide resonance eliminator to protect the ferromagnetic resonance of the electromagnetic voltage transformer, it is more common. According to statistics, after the installation of the primary resonance eliminator, the transformer explosion and Power grid accidents account for the vast majority

[0004] However, after the end of the primary winding of the electromagnetic voltage transformer is short-circuited with the end of the secondary winding or the iron core, because the resonance eliminator is a large resistance, the end of the primary winding and the secondary winding or the iron core and the grounding point do not form a loop, which hides Solved the insulation problem of the tail end of the primary winding of the electromagnetic voltage transformer

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