Dry type voltage transformer for switchgear

Abstract

The invention relates to a dry type voltage transformer for switchgear. The dry type voltage transformer for the switchgear is characterized in that balancing windings with the number of turns identical to the geometric dimensioning are arranged on two core columns of a rectangular iron core; cascade type high voltage primary windings with the number of turns identical to the geometric dimensioning and in tandem connection are arranged outside the two balancing windings; a series connection joint is in equipotential connection with the iron core; a low voltage secondary winding is arranged outside one high voltage primary winding; an insulating hoisting element is arranged on a low voltage winding side; one end of the insulating hoisting element is fixed on an iron yoke of the iron core; damping shielding layers with certain radius of curvature and thickness are arranged outside the high voltage primary windings, the low voltage secondary winding, the exposed iron core, high voltage leads and low voltage leads; an insulating conservation body is arranged outside a dry type voltage transformer body; an aluminum film layer and stainless steel are sequentially arranged on the surface of the insulating conservation body which is arranged outside an air chamber of the switchgear. The dry type voltage transformer for the switchgear has the advantages of enabling excitation loss of the iron core to be reduced, being small in unload current and high in overvoltage bearing capability and satisfying 66 KV switchgear requirements for utilization.

Description

technical field [0001] The invention relates to a voltage transformer, in particular to a dry-type voltage transformer for 66kV gas insulated switchgear in a power distribution system. Background technique [0002] With the development of 66kV gas insulated switchgear C-GIS in the power distribution system to the direction of miniaturization, intelligence and structural modularization, the volume of switchgear is reduced by nearly 2 / 3 compared with traditional equipment. The existing voltage transformer used for 66kV switchgear is not reasonable due to its iron core, high-voltage primary winding, low-voltage secondary winding and balance winding, etc. Composite insulation makes the voltage transformer bulky and heavy, which can no longer meet the requirements of miniaturized switchgear. The dry-type voltage transformer casted with epoxy resin has the advantages of small size, fully enclosed, oil-free, and maintenance-free, but because of the low voltage level of insulation ...

AI Technical Summary

Problems solved by technology

The existing voltage transformer used for 66kV switchgear is not reasonable due to its iron core, high-voltage primary winding, low-voltage secondary winding and balance winding, etc. Composite insulation makes the voltage transformer bulky and heavy, which can no longer meet the requirements of miniaturized switchgear

Although the dry-type voltage transformer casted with epoxy resin has the advantages of small size, fully enclosed, oil-free, and maintenance-free, but because of the low voltage level of insulation protection, it is only suitable for low voltage levels, that is, 40kV and below. It is used in the occasion of the voltage level, and it is used on the switchgear of 66kV, which is prone to breakdown and affects the normal operation of the power grid, and the scope of use is limited

Images