Internal field intensity balancing device for medium-voltage mutual inductor

Abstract

The invention discloses an internal field intensity balancing device for a medium-voltage mutual inductor. The device comprises semiconductor crinkled paper of different surface resistance values wound on the outermost layer of a primary winding, wherein the semiconductor crinkled paper of smaller surface resistance values is arranged in regions with higher field intensities of the primary winding and a secondary winding; the semiconductor crinkled paper of larger surface resistance values is arranged in regions with lower field intensities of the primary winding and the secondary winding; and a space between the primary winding and the secondary winding is filled with a main insulator. Through adoption of the device, the field intensities between the primary winding and the secondary winding can be balanced; the partial discharge amount is reduced; the original structures of the primary winding and the secondary winding are kept constant; and the parameters of the medium-voltage mutual inductor are not reduced.

Description

technical field [0001] The invention relates to the technical field of transformers, in particular to a device for equalizing field strength inside a medium-voltage transformer. Background technique [0002] Transformer, also known as instrument transformer, is a general term for current transformer and voltage transformer. It can change high voltage into low voltage and large current into small current for measurement or protection system. Its function is mainly to convert high voltage or high current into standard low voltage or standard small current in proportion, so as to realize the standardization and miniaturization of measuring instruments, protection equipment and automatic control equipment. [0003] The medium voltage transformer refers to the primary side voltage of 3kV-35kV. The medium voltage transformer needs to assess the internal partial discharge. The smaller the partial discharge, the better, and the factor that affects the partial discharge is the balan...

AI Technical Summary

Problems solved by technology

[0004] In order to prevent partial discharge, semiconductor shielding materials are often installed between the primary winding and the secondary winding, and no special treatment is performed to balance the electric field. For projects that require relatively high partial discharge, in order to reduce partial discharge The amount is often achieved by increasing the insulation distance between the primary and secondary windings. This method will inevitably sacrifice other parameters, such as capacity, protection factor and reduced accuracy.

Alternatively, adding a metal shield between the primary winding and the secondary winding is not only troublesome to operate, but also increases the chance of insulation breakdown

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