SU564661A1 - Current transformer - Google Patents

Description

one

The invention relates to the field of electrical engineering and can be used in the implementation of relay protection devices and automation of electrical systems.

In known current transformers containing high voltage (secondary winding and partitioned magnetic core, all sections of the latter are grounded, which requires internal insulation (insulation of the primary winding) for the rated voltage,

The purpose of the invention is to simplify internal insulation and reduce its cost.

For this purpose, in the proposed current transformer, this insulation is installed between the poles of the sections of the magnetic circuit, on which electrostatic screens are located, and the primary winding is placed on its ungrounded section.

The drawing shows the proposed current transformer.

High voltage primary winding 1 and. the low-voltage secondary winding 2 has an extremely simplified insulation and, in order to eliminate its breakdown from capacitive voltages applied to the sections of the magnetic circuit, is galvanically connected to the corresponding sections 3 and 4 on which they are located.

Section .3, on which winding 1 is placed, is made ungrounded, section 4 and winding 2 placed on it are grounded. To reduce the size of the gaps between the sections of the magnetic circuit, electrostatic screens 5 are used. The sections of the magnetic circuit are attached to the porcelain tire 6 by non-thread bars 7.

The required electrical strength between the sections of the magnetic core is achieved by filling the internal cavity of the current transformer and, in particular, nonmagnetic gaps, with compressed gas, a liquid or solid dielectric. When used in the internal insulation of a solid dielectric, porcelain coating 6 is not required.

To increase the emf of the useful signal and reduce the emf of interference (from wires of other phases), the secondary winding is expediently made of two connected