SU94389A1 - Heartless plug-in current transformer - Google Patents

Description

During operation of carbide furnaces, it is necessary to measure the amount of current in parallel branches of a short network that supplies electrical current to the furnace electrodes. This must be done to determine the state of electrical contact between the electrodes and the contact plates, since poor contact leads to damage (burning) of the plates and an emergency stop of the furnace.

Measuring the current in a short circuit presents a considerable difficulty, especially in the section of tubular pieces located in close proximity to the electrodes. Due to the high temperature of waste gases washing the entire zone of these tires, the use of stationary current transformers is impossible due to the burning of their windings.

Conventional mites under the conditions described are also unsuitable for use. A strong magnetic field created by the current flowing in the wakes of the order of tens of thousands of amperes would require the use of such a large cross section in the magnetic tongs that it would be impossible to use the tongs due to the small distances and the need to mount the tongs on the bars long 3-4 m according to the conditions of the location of the tires above the floor of the room and the impossibility of approaching the kiln due to the high TeNraepaTypbi (500-600 °).

Making mites with an elastic magnetic conductor of a small cross section would lead to excessive overheating of the steel and, as a result, to the insulation of the winding.

Finally, indirect methods for determining the state of contacts (for example, measuring the amount of heat removed by water, cooling pipe and contact plates: an optical method using pyrometers; a superposition method consisting of imposing a direct current on an alternating current, etc.) reasons do not give the desired results.

For the above considerations, the only real way to determine the quality of contacts in carbide furnaces, etc., is to measure the current

Screws with the help of measuring tongs with an air magnetic circuit, i.e. using a heartless detachable current transformer.

The subject of the present invention is a similar current transformer. It is made in the form of an annular solenoid spanning a bar with a measured current, and according to the invention, the solenoid is fixed inside an elastic ring-shaped holder fixed to the pieces a-ngi fitted with arc-shaped horns in place of the connector current and taking it off miffibi. The bus is the nepBH4iwro winding of the transformer, and the solenon is its secondary winding.,

FIG. 1 and 2 - the general view of the transformer in two projections is depicted; in fig. 3 - measuring pole with a transformer attached to it.

The transformer action is based on the use of the complete law: TOKav according to which the sum of the products of elements of length arbitrary z: amqn) of the contour by the longitudinal-component vector, for example. of the non-magnetic field throughout, the contour is equal to the algebraic sum of the currents penetrating this contour; ..

The transformer consists of a ring-shaped: -, split solenoid /, representing; is a toroidal 1 ob & tk-- C-turns (on the order of 40 DO) in p-shaped ones; B1-several layers, and ME ALLGSH.Tech- holder 2

(casing). The latter is made of strip steel in the form of a cut ring, the ends of which are moved apart during use of the bar. The solenoid is located on the inner surface of the cage and fixed on it at five points.

At the ends of the cage, two horns 3 that are in contact with each other are fastened.

The operator, holding the barbell in the arm. X, applies the transformer to the tire with the outer surface of the horns 3 and, under light pressure, pulls the solenoid onto the tire. In this case, the horns are moved apart, allowing the solenoid to engage the tire, and then re-close due to the spring action of the yoke. After the measurement is made, the solenoid is removed from the tire.

Subject invention

Heartless disconnect

a current transformer, which is a ring solenoid, covering the bus with a measured current, which means that, in order to measure the current from a distance of 3-4 m from the bus, the solenoid is hardened inside an elastic an annular cage, secured at the end of the rod and fitted with arcuate horns in place of the connector, facilitating the fitting of the solenoid with the measured current rm and taking it off from the pinch.

FIG. 2

FIG.