CN117976382A - Low-closing excitation surge current transformer - Google Patents

Abstract

The invention discloses a low-closing excitation surge current transformer, which comprises an iron core, a secondary side coil and a primary side coil, wherein the iron core is arranged on the primary side coil; the iron core is provided with an iron core column; the secondary side coil is sleeved on the outer surface of the iron core column and is used as an output coil of the transformer; the primary coil is sleeved on the outer surface of the secondary coil and is used as an input coil of the transformer; the secondary side coil is sleeved on the outer surface of the iron core column to serve as an output coil of the transformer, and the primary side coil is sleeved on the outer surface of the secondary side coil to serve as an input coil of the transformer; and reasonable working magnetic density Bm of the transformer iron core is selected, so that the inductance of a primary side coil of the transformer is increased, and the closing excitation surge current is effectively reduced.

Description

Low-closing excitation surge current transformer

Technical Field

The invention relates to the technical field of transformers, in particular to a low-closing excitation surge current transformer.

Background

In an electric power system, a transformer is a key device and plays an important role in voltage conversion and electric energy transmission; however, during operation of the transformer, switching-on excitation surge is a problem that cannot be ignored; the switching-on excitation surge current refers to instantaneous high current generated at the moment of switching-on of the transformer because magnetic flux in the iron core cannot be suddenly changed; the inrush current not only can damage the transformer, but also can influence the stability of the power system; therefore, the characteristics of the switching-on excitation surge current of the transformer and the coping strategies thereof are studied in depth, and the method has important significance for guaranteeing safe and stable operation of the power system.

In the prior art, the method for reducing the switching-on excitation surge current of the transformer mainly comprises the following steps: firstly, by increasing the impedance of the transformer, the excitation surge current is reduced; secondly, the excitation surge current is dispersed by changing the wiring mode of the transformer; thirdly, absorbing the energy of excitation surge current by arranging a damper or a reactor; however, these methods have certain problems, such as increasing the impedance of the transformer affects the transmission efficiency, changing the wiring mode increases the complexity of the system, and setting a damper or a reactor increases the investment cost of the device; therefore, a new method for effectively reducing the excitation surge current without affecting the performance and the system stability of the transformer is needed to be found.

Disclosure of Invention

In view of the above, the present invention provides a low-switching-on excitation surge transformer, which aims to solve the above technical problems.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a low-closing excitation surge transformer comprises an iron core, a secondary side coil and a primary side coil;

The iron core is provided with an iron core column;

the secondary side coil is sleeved on the outer surface of the iron core column and is used as an output coil of the transformer;

the primary coil is sleeved on the outer surface of the secondary coil and serves as an input coil of the transformer.

Preferably, the iron core is a zigzag structure formed by integrally molding an upper iron yoke, an iron core column and a lower iron yoke.

Preferably, the iron core is formed by stacking silicon steel sheets and is fixedly connected by brushing special glue for the iron core.

Preferably, the iron core fixing device further comprises two clamping fasteners, wherein the two clamping fasteners are respectively positioned at the upper end and the lower end of the iron core and used for clamping and fixing the iron core, and the two clamping fasteners are connected through a pull rod.

Preferably, the clamping fastener comprises a clamping piece and a clamping screw;

The number of the clamping pieces is two, and the two clamping pieces are respectively positioned at two sides of the iron core;

And the clamping screws are used for fixedly connecting the two clamping pieces positioned on two sides of the iron core.

Preferably, the secondary side coil further comprises a bus copper bar, and the bus copper bar is respectively connected with the output end of the secondary side coil and the input end of the primary side coil.

Preferably, the working magnetic density Bm of the transformer core is lower than that of a conventional transformer core.

Compared with the prior art, the invention discloses the low-closing excitation surge current transformer, which has the following beneficial effects:

The secondary side coil is sleeved on the outer surface of the iron core column to serve as an output coil of the transformer, and the primary side coil is sleeved on the outer surface of the secondary side coil to serve as an input coil of the transformer; and reasonable working magnetic density Bm of the transformer iron core is selected, so that the inductance of a primary side coil of the transformer is increased, and the closing excitation surge current is effectively reduced.

The primary coil is sleeved on the outer surface of the secondary coil, so that the inductance of the primary coil can be increased, the impedance is improved, and the closing excitation surge current is reduced.

According to the invention, extra equipment is not required to be added, the complexity and investment cost of the system are not increased, the switching-on excitation surge current of the transformer can be effectively reduced, and the performance and the system stability of the transformer are not influenced; the method is suitable for various types of transformers, and has wide application prospect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of the overall structure provided by the present invention;

FIG. 2 is a schematic diagram of a front view structure provided by the present invention;

FIG. 3 is a schematic view of the iron core structure provided by the invention;

FIG. 4 is a schematic view of a secondary side coil structure according to the present invention;

wherein:

1. A core; 2. a secondary side coil; 3. a primary side coil; 4. a core limb; 5. an upper yoke; 6. a lower yoke; 7. a pull rod; 8. a clamping piece; 9. clamping a screw; 10. and a busbar copper.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1 to 4, the embodiment of the invention discloses a low-closing excitation surge transformer, which comprises an iron core 1, a secondary side coil 2 and a primary side coil 3;

The core 1 has core limbs 4;

the secondary side coil 2 is sleeved on the outer surface of the iron core column 4 and is used as an output coil of the transformer;

the primary coil 3 is sleeved on the outer surface of the secondary coil 2 and serves as an input coil of the transformer.

In the embodiment, the secondary side coil 2 is wound by adopting a common winding structure, and is sleeved on the outer surface of the iron core column 4 after the winding is completed to serve as an output coil of the transformer; the primary coil 3 is sleeved on the outer surface of the secondary coil 2 after being wound and is used as an input coil of the transformer; the secondary coil 2 and the primary coil 3 can be fixedly connected through a dovetail stay.

In order to further optimize the technical scheme, the iron core 1 is of a Chinese character 'ri' shaped structure formed by integrally forming the upper iron yoke 5, the iron core limb 4 and the lower iron yoke 6.

In order to further optimize the technical scheme, the iron core 1 is formed by stacking silicon steel sheets and is fixedly connected by brushing special glue for the iron core.

In the embodiment, the iron core 1 adopts high-quality oriented silicon steel sheets, and is stacked into a required structure after being cut by oblique cutting lines; the stacked iron core 1 is clamped and fixed by a clamping fastener, and is coated and fixed by special glue for the iron core.

In order to further optimize the technical scheme, the iron core fixing device further comprises two clamping fasteners, wherein the two clamping fasteners are respectively positioned at the upper end and the lower end of the iron core 1 and used for clamping and fixing the iron core 1, and the two clamping fasteners are connected through a pull rod 7.

In order to further optimise the solution described above, the clamping fastener comprises a clamping piece 8 and a clamping screw 9;

The number of the clamping pieces 8 is two, and the two clamping pieces 8 are respectively positioned at two sides of the iron core;

a plurality of clamping screws 9 connect and fix two clamping pieces 8 located on two sides of the core.

In the embodiment, the iron core 1 is of a Chinese character 'ri' shaped structure and is provided with an upper iron yoke 5, an iron core column 4 and a lower iron yoke 6, two clamping fasteners are respectively and fixedly connected with the upper iron yoke 5 and the lower iron yoke 6, and the upper clamping fastener and the lower clamping fastener are fixedly connected through a pull rod 7; the clamping fastener comprises two clamping pieces 8, wherein the two clamping pieces 8 are respectively positioned at two sides of the iron yoke, and are connected and fixed through a clamping screw 9.

In order to further optimize the above technical solution, the device further comprises a busbar copper bar 10, wherein the busbar copper bar 10 is respectively connected with the output end of the secondary coil 2 and the input end of the primary coil 3.

The bus bar copper 10 is connected with the secondary side coil 2 and the primary side coil 3 through bolts, and the connection mode is the conventional means and is not described herein; the upper and lower ends of the busbar 10 are connected with the clamping piece 8 through the connecting plate and the bolts, so that the stability of the busbar 10 is improved, and the connecting mode is the conventional means and is not repeated here.

In order to further optimize the technical scheme, the working magnetic density Bm of the transformer core is lower than that of a conventional transformer core.

According to the invention, the number of turns of the primary side coil 3 is increased by selecting the reasonable working magnetic density Bm of the transformer iron core 1, and the inductance and impedance of the primary side coil 3 can be effectively increased, so that the closing excitation surge current of the transformer is effectively reduced.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. The low-closing excitation surge transformer is characterized by comprising an iron core, a secondary side coil and a primary side coil;

The iron core is provided with an iron core column;

the secondary side coil is sleeved on the outer surface of the iron core column and is used as an output coil of the transformer;

the primary coil is sleeved on the outer surface of the secondary coil and serves as an input coil of the transformer.

2. The low-closing excitation surge transformer of claim 1, wherein the iron core is a delta-shaped structure formed by integrally forming an upper iron yoke, an iron core limb and a lower iron yoke.

3. The low-closing excitation surge transformer of claim 1, wherein the core is formed by stacking silicon steel sheets and fixedly connected by applying special glue to the core.

4. The low-closing excitation surge transformer of claim 1, further comprising two clamping fasteners, wherein the two clamping fasteners are respectively located at the upper end and the lower end of the iron core and used for clamping and fixing the iron core, and the two clamping fasteners are connected through a pull rod.

5. The low-closing magnetizing inrush current transformer of claim 4, wherein the clamping fasteners comprise clamping members and clamping screws;

The number of the clamping pieces is two, and the two clamping pieces are respectively positioned at two sides of the iron core;

And the clamping screws are used for fixedly connecting the two clamping pieces positioned on two sides of the iron core.

6. The low-closing excitation surge transformer of claim 1, further comprising a bus bar connected to the output of the secondary side coil and the input of the primary side coil, respectively.