SU489178A1 - Current transformer - Google Patents

Description

one

I Invention SUCCESSES to electrical engineering, more precisely to machines and apparatuses of electrical power plants.

In the known current transformers containing primary and secondary windings, the magnetic circuit and the housing with a jumper fixed on it, the jumper is located between the secondary windings, executed in the form of rods and has bent edges. The jumper is fixed on the stud screwed into the housing and is isolated from it by the sleeve.

The folded edges of the web rest against the notches in the rods of the lead ends.

in a winding, shorting it.

When the winding is deshunted, the nut fastening the jumper to the stud is lowered, the jumper is pivoted by 9 ° and fixed in this position. However, with this design, the most dangerous mode of operation of the tsfichny chain is observed at the moment of its opening, at which significant emf occurs. at the output of the secondary winding of the current transformer.

The purpose of the invention is to provide automatic shunting of the secondary winding of the current transformer prior to disconnecting the conductor of the external secondary circuit.

To do this, in the proposed device, the jumper is made of two flexible conductor segments, each of which, independently of the other, is electrically connected at one end with a bracket connected in turn with a secondary winding terminal, and the other end with a tip, the contact protrusion of which is located under the bracket of the other output of the secondary winding, and under both tips there are springs whose travel is less than the travel of the springs located on the screws screwed into the brackets.

FIG. 1 and 2 schematically depict the proposed device.

On the case of the current transformer with screws 1 installed brackets 2 OUTPUT 3 secondary winding. The screws 4 fasteners, conductors 5 of the external secondary circuit are turned into brackets.

On screw 4 there is a spring 6 and its j cup 7, the outer secondary circuit conductor is located between the cup and the screw head. To reduce the contact resistance of the cup 7, it is galvanically connected to the bracket 2. The tip 8 of the flexible bridge 9 is located under the bracket 2 and is pushed out of the transformer casing by the spring iO in the casing C, which is fixed under the same bracket to the transformer housing 12. The stroke of the springs 10, located under the tip 8, is greater than the stroke of the springs 6, located on the screws 4 screwed in the brackets. The arc end of the flexible jumper 9 is galvanically connected to the bracket of the other terminal 3 of the secondary winding of the current transformer.

The bypass of the secondary winding in the normal mode is prevented by a screw 4, abutting the tip 8 through a plate of electrically insulated material 13.

To improve contact with shunt -; The secondary winding institute tip 8 has a projection with which it touches bracket 2.

The device works as follows.

When powering the external secondary circuit from the secondary winding of the current transformer, the screw 4 is fully wrapped and the tip 8 is pulled out of the bracket 2.

The external secondary circuit is connected to the transformer by conductors 5 through screw 4, cup 7, spring 6 and bracket 2, to which pin 3 of the secondary winding of the current transformer is attached. Before disconnecting any of the conductors 5 of the external secondary circuit, the screw 4 is unscrewed and the tip 8 is pressed by the contact lip to the bracket 2 by the spring 10 by shunting the secondary winding. Blae

The fact that the spring travel 10, located under the tips 8, is greater than the spring travel 6, located on the screws 4 screwed into the brackets, does not have an external secondary circuit open, as the spring 6 pushes the external conductor 5 to the screw 4 through the glass 7.

With full unscrewing of screw 4, it is possible to safely disconnect the conductor 5 of the external circuit from the transformer, since its secondary winding has previously been shunted with a flexible jumper.

Regardless of the position of the screw 4 on one bracket, you can likewise disconnect the conductor of the external circuit from the other bracket.

An external secondary circuit is connected to the secondary winding of the current transformer in reverse order.

Subject invention

The current transformer containing the primary and secondary windings, the magnetic core, the housing and the shunt jumpers of the secondary windings, and at least one of the ends of the jumper is isolated from the current-carrying parts, and with In order to prevent damage to the current transformer when the external secondary circuit is disconnected by shunting its secondary winding before the external circuit is disconnected, the jumper is made of two flexible conductor segments, each of which, independently of the other, is electrically connected the end with the bracket connected in turn with the output of the secondary winding, and the other end with the tip, the contact protrusion of which is located under the bracket of the other output of the secondary winding, and springs with less tips of the springs located on the screwed in brackets screws.

FIG. 2