CN217425508U

CN217425508U - Secondary side current sampling circuit of electric furnace transformer

Info

Publication number: CN217425508U
Application number: CN202122614892.2U
Authority: CN
Inventors: 李英伟; 王庆如; 王建军; 郭洋
Original assignee: Sinopec Engineering Group Co Ltd; Sinopec Nanjing Engineering Co Ltd
Current assignee: Sinopec Engineering Group Co Ltd; Sinopec Nanjing Engineering Co Ltd
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-09-13
Anticipated expiration: 2031-10-28

Abstract

The utility model discloses an electric furnace transformer secondary side current sampling circuit, high-voltage bus connects electric furnace transformer's the side that once inclines, and its characterized in that secondary side forms heavy current output by a plurality of undercurrent windings after parallelly connected, respectively installs a current sensor additional on all undercurrent windings, and all current transformer's secondary current draws forth the transformer and gathers outward. The current transformers are additionally arranged on the small current windings in the transformer body, the secondary sides of the current transformers in the same phase are led out of the transformer and then connected in parallel, so that a sum current capable of reflecting the current of the short network is formed, and the problem that the large current short network cannot carry out high-precision current sampling can be effectively solved.

Description

Secondary side current sampling circuit of electric furnace transformer

Technical Field

The utility model belongs to the technical field of electrical design and installation, concretely relates to electric stove transformer secondary side current sampling circuit.

Background

The traditional electric furnace transformer has the problems that the current output of the secondary outgoing line side is very large, the current sampling is difficult (a proper current transformer cannot be selected), although the current sampling can be carried out on a short network by a method of installing a Rogowski coil, the accuracy and the service life of the traditional electric furnace transformer cannot reach satisfactory ground level. The current of the short net is monitored in real time, which is necessary for operators.

How to sample a high-precision current value and ensure the service life is a problem which needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

The utility model provides an electric stove transformer secondary side current sampling circuit to the problem that exists among the background art.

The technical scheme is as follows:

a high-voltage bus is connected with the primary side of an electric furnace transformer, the secondary side of the electric furnace transformer is connected in parallel by a plurality of small current windings to form large current output, all the small current windings are respectively and additionally provided with a current sensor, and the secondary currents of all the current transformers are led out of the transformer to be collected.

As a preferable secondary current summarizing scheme, secondary currents of all current transformers are connected in parallel and then connected in series with an ammeter so as to obtain total current sampling data of the secondary side of the electric furnace transformer.

The beneficial effects of the utility model

The current transformers are additionally arranged on the small current windings in the transformer body, the secondary sides of the current transformers in the same phase are led out of the transformer and then connected in parallel, so that a sum current capable of reflecting the current of the short network is formed, and the problem that the large current short network cannot carry out high-precision current sampling can be effectively solved.

Drawings

FIG. 1 is an equivalent wiring diagram of an electric furnace transformer

FIG. 2 is a diagram of equivalent wiring transformation of an electric furnace transformer

FIG. 3 is the equivalent wiring diagram of the electric furnace transformer with current transformer of the utility model

FIG. 4 is a circuit diagram of a secondary current collection circuit according to an embodiment

Detailed Description

The present invention will be further described with reference to the following examples, but the scope of the present invention is not limited thereto:

fig. 1 is an equivalent wiring diagram of a conventional electric furnace transformer, which is taken as an example of a single phase. The high-voltage side winding converts the high-voltage electric energy at the primary side into a current loop and a voltage regulating loop through electromagnetic induction, and a secondary side output loop of the transformer connected with the short network is connected with the voltage regulating loop through the current loop to realize the functions of current regulation and voltage regulation of the electric furnace.

The equivalent wiring transformation diagram of the electric furnace transformer shown in FIG. 2 is an equivalent diagram which is detailed on the basis of FIG. 1. Due to manufacturing reasons, the current winding of the transformer body cannot realize single-winding large-current output, and a plurality of smaller current windings are connected in parallel to form large-current output. Fig. 2 illustrates the wiring principle of a large current output formed by connecting a plurality of small current windings in parallel.

As shown in an equivalent wiring diagram of an electric furnace transformer with a current transformer in fig. 3, a current transformer is added to each small current winding in the equivalent diagram in fig. 2, so that the sampling current of each small current winding is led out to a terminal outside the transformer for standby through a plurality of small current transformers.

As shown in an equivalent wiring diagram of the current transformer in fig. 4, the secondary sides of the current transformers in the same phase in fig. 3 are connected in parallel to form a wiring capable of reflecting the actual output current of the electric furnace transformer, and the actual output current value can be obtained as shown in an ammeter a of the diagram.

Based on the circuit improvement, the method for sampling the secondary side current of the electric furnace transformer is summarized as follows:

s1: as shown in an equivalent wiring diagram of the electric furnace transformer in fig. 1, a dashed line frame is an element in the body of the electric furnace transformer, and a bus connected with an outlet end of the electric furnace transformer is called as a short net;

s2: because the secondary side outlet current of the electric furnace transformer is very large, the large-current outlet is actually realized by connecting a plurality of smaller current windings (small current windings for short) in parallel to form large output current, such as an equivalent wiring conversion diagram of the electric furnace transformer shown in fig. 2;

s3: in the transformer body, a current transformer (such as TA1, TA2.. TAn in fig. 3) is additionally arranged on each of a plurality of small current windings, and the secondary current of the current transformers is led out of the transformer;

s4: and connecting the secondary currents of the current transformers in the same phase in the S3 as shown in FIG. 4 to obtain total current sampling data of the short net A1-X1 loop.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

The utility model discloses the part that does not relate to all is the same with prior art or can adopt prior art to realize.

Claims

1. A secondary side current sampling circuit of an electric furnace transformer is characterized in that a secondary side is connected with a primary side of the electric furnace transformer in parallel by a plurality of small current windings to form a large current output, a current sensor is additionally arranged on each small current winding, and secondary currents of all current transformers are led out of the transformer to be collected.

2. The secondary side current sampling circuit of the electric furnace transformer as claimed in claim 1, wherein the secondary currents of the current transformers are connected in parallel and then connected in series with an ammeter for obtaining the total current sampling data of the secondary side of the electric furnace transformer.