CN111968824A - Transformer neutral point complete protection device - Google Patents

Abstract

The invention discloses a complete set of protection device for the neutral point of a transformer, comprising: a steel column, a mounting base with a T-shaped structure, a lightning arrester, a current transformer and a neutral point isolating switch arranged at the end of the mounting base. The device is connected to the ground, the installation base is horizontally arranged on the steel column, the arrester is provided with a first connection terminal board, the current transformer is provided with an upper connection board, and a discharge gap bar is arranged between the upper connection board and the first connection terminal board. The neutral point isolation switch is provided with a second connection terminal board, and the second connection terminal board is respectively connected with the neutral point of the transformer and the first connection terminal board through wires. The invention combines the arrester, the current transformer and the neutral point isolating switch into a compact whole through the T-shaped mounting base, which can greatly shorten the overall length of the complete set of protection devices for the neutral point of the transformer, reduce the occupied space, and can be used in indoor space. Sufficient electrical safety distance is met in limited circumstances.

Description

A complete set of protection device for transformer neutral point

technical field

The invention relates to the technical field of electric power equipment, in particular to a complete set of protection device for the neutral point of a transformer.

Background technique

The neutral point grounding method of the power system transformer is closely related to the reliability and safety of the power supply of the system, the overvoltage and insulation coordination of the transformer, the setting and configuration of the relay protection device, and the interference of the communication network system. In the past, in the medium-voltage power grid, the neutral point of the transformer was generally not grounded. Due to the small capacity of the power grid, even if a single-phase short-circuit fault occurs, the normal operation of the system will not be affected. With the gradual increase in the length of the power grid transmission line, the improvement of the voltage level, the complexity of the power grid wiring, and the continuous expansion of the power grid capacity, the transformer gradually adopts the method of direct grounding of the neutral point. However, when the system fails, this grounding method will generate a huge short-circuit current, resulting in very serious damage to the power equipment. In addition, due to incorrect wiring or other reasons, the malfunction of the system relay protection device may lead to the power system. The phenomenon of partial ungrounding occurs.

In order to improve the safety, stability and reliability of the power system, the current practice is to set up a complete set of protection devices at the neutral point of the transformer. However, the current complete set of transformer neutral point protection devices are arranged in a row, occupying a large area, and the transformers arranged indoors have limited space, so the existing transformer neutral point complete sets of protection devices cannot fully meet the requirements of indoor use. .

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the present invention proposes a complete set of protection device for the neutral point of the transformer with compact structure.

A complete set of protection device for transformer neutral point according to an embodiment of the present invention includes: a steel column, a mounting base with a T-shaped structure, a surge arrester, a current transformer, and a neutral point isolating switch arranged at the end of the mounting base. The steel column is connected to the ground through a fastening device, the installation base is horizontally arranged on the steel column, the arrester is provided with a first terminal board, the current transformer is provided with an upper connection plate, and the upper connection There is a discharge gap bar between the board and the first terminal board, the neutral point isolation switch is provided with a second terminal board, and the second terminal board is connected to the neutral point of the transformer and the The first connection terminal board is connected.

The complete set of protection device for the neutral point of the transformer according to the above embodiments of the present invention has at least the following beneficial effects: the arrester, the current transformer and the neutral point isolating switch are formed into a compact whole through the T-shaped mounting base, which can greatly shorten the neutral point of the transformer. Point the overall length of the protective set, reduce its footprint, and can meet sufficient electrical safety distance in the case of limited indoor space.

According to some embodiments of the present invention, the mounting base includes a cuboid-shaped first base and a second base, the arrester and the current transformer are respectively disposed at two ends of the first base, and the neutral point The isolation switch is arranged on the second base and away from the first base.

According to some embodiments of the present invention, a support seat is provided between the first base and the arrester.

According to some embodiments of the present invention, the discharge gap of the discharge gap bar is set to be 90mm to 150mm.

According to some embodiments of the present invention, a knife is provided on one side of the neutral point isolating switch.

According to some embodiments of the present invention, an operating mechanism connected to the neutral point isolation switch is provided on the steel column.

According to some embodiments of the present invention, a discharge counter connected to the arrester is provided on the steel column.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a top view of an embodiment of the present invention;

2 is a left side view of an embodiment of the present invention;

FIG. 3 is a front view of an embodiment of the present invention.

Reference number:

Steel column 100, operating mechanism 101, discharge counter 102;

Install the base 200, the first base 201, and the second base 202;

Lightning arrester 300, first terminal board 301, support base 302;

Current transformer 400, upper connecting plate 401;

Discharge gap bar 500;

Neutral point isolating switch 600 , second terminal board 601 , knife 602 .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

In the description of the present invention, it should be understood that the orientations related to the description, such as up, down, front, rear, left, right, etc., are based on the orientation or positional relationship shown in the drawings, and are only In order to facilitate the description of the present invention and simplify the description, it is not indicated or implied that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description of the present invention, unless otherwise clearly defined, terms such as setting, installation, and connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

Referring to FIGS. 1 to 3 , a complete set of protection devices for the neutral point of a transformer according to an embodiment of the present invention includes: a steel column 100 , a mounting base 200 with a T-shaped structure, lightning arresters 300 , current Transformer 400 , neutral point isolation switch 600 .

The steel column 100 is connected to the ground through a fastening device, and the fastening device here is preferably an anchor bolt, of course, other fastening devices that can meet the construction requirements can also be used. The installation base 200 is horizontally installed on the steel column 100, the installation base 200 is provided with a ground wire, the top of the arrester 300 is provided with a first terminal board 301, the top of the current transformer 400 is provided with an upper connecting plate 401, and the current transformer 400 It is also connected to the mounting base 200 through a long grounding aluminum bar. The current transformer model here is LZZBW-10. A discharge gap bar 500 is provided between the upper connecting plate 401 and the first terminal board 301, and the neutral point isolation switch 600 is set. There is a second connection terminal board 601, and the second connection terminal board 601 is respectively connected with the neutral point of the transformer and the first connection terminal board 301 through wires. When the voltage of the neutral point isolating switch 600 rises, the discharge gap rod 500 is broken down to cause an arc, and the neutral point isolating switch 600 is grounded; after the voltage of the neutral point isolating switch 600 is lowered, the arc is extinguished, and the neutral point isolating switch 600 is turned off again. Not grounded.

In some embodiments of the present invention, the installation base 200 includes a rectangular parallelepiped first base 201 and a second base 202, the first base 201 and the second base 202 are fixed on the steel column 100 by bolts and form a T-shaped structure. The installation base 200 , the arrester 300 and the current transformer 400 are respectively installed on both ends of the first base 201 , and the neutral point isolating switch 600 is installed on the second base 202 at one end of the second base 202 away from the first base 201 .

The longitudinal length of the existing complete set of transformer neutral point protection device arranged in a row can reach 3000mm, while the longitudinal length of the transformer neutral point complete set of protection device in the above embodiment is only 1800mm, so the complete set of transformer neutral point can be greatly shortened. Overall length of the guard.

In some embodiments of the present invention, a support base 302 is provided between the first base 201 and the arrester 300 for effectively fixing the arrester 300 and making the arrester 300 vertically arranged.

In some embodiments of the present invention, the discharge gap of the discharge gap bar 500 is adjustable, and the adjustment range is 90 mm to 150 mm. The adjustment range of the discharge gap is consistent with the existing complete set of protection devices for the neutral point of the transformer arranged in a row, and the lateral length of this embodiment is only 1109 mm when the discharge gap remains unchanged.

In some embodiments of the present invention, one side of the neutral point isolating switch 600 is provided with a knife 602, and the knife 602 is connected to the mounting base 200 through a tinned copper wire.

In some embodiments of the present invention, the steel column 100 is provided with an operating mechanism 101 connected to the neutral point isolating switch 600 , and the operating mechanism 101 is used to control the neutral point isolating switch 600 to perform the opening/closing action. This embodiment In the example, an electric operating mechanism is used, and the model is GJ12D.

In some embodiments of the present invention, the steel column 100 is provided with a discharge counter 102 connected to the arrester 300 for monitoring the discharge times and leakage current of the arrester 300 .

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples," or the like, is meant to incorporate the embodiments. A particular feature, structure, material or characteristic described or exemplified is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, The scope of the invention is defined by the claims and their equivalents.

Claims (7)

1. A transformer neutral point complete protection device is characterized by comprising:

the steel upright post (100), the steel upright post (100) is connected with the ground through a fastening device;

the mounting base (200) of the T-shaped structure is horizontally arranged on the steel upright post (100);

and arranged at the end of the mounting base (200)

A lightning arrester (300) provided with a first terminal board (301);

a current transformer (400) provided with an upper connection plate (401), a discharge gap bar (500) being provided between the upper connection plate (401) and the first terminal board (301);

the neutral point isolating switch (600) is provided with a second terminal board (601), and the second terminal board (601) is respectively connected with a transformer neutral point and the first terminal board (301) through leads.

2. The transformer neutral point complete protection device according to claim 1, characterized in that the mounting base (200) comprises a first base (201) and a second base (202) which are rectangular parallelepiped-shaped, the lightning arrester (300) and the current transformer (400) are respectively arranged at two ends of the first base (201), and the neutral point isolating switch (600) is arranged on the second base (202) and is far away from the first base (201).

3. The transformer neutral point complete protection device according to claim 2, characterized in that a support base (302) is arranged between the first base (201) and the lightning arrester (300).

4. The transformer neutral point complete protection device according to any one of claims 1 to 3, wherein a discharge gap of the discharge gap rod (500) is set to 90mm to 150 mm.

5. The transformer neutral point complete protection device according to claim 1, characterized in that a knife switch (602) is arranged on one side of the neutral point isolating switch (600).

6. The transformer neutral point complete protection device according to claim 1, characterized in that an operating mechanism (101) connected with the neutral point isolating switch (600) is arranged on the steel upright post (100).

7. The transformer neutral point complete protection device according to claim 1, characterized in that a discharge counter (102) connected with the lightning arrester (300) is arranged on the steel upright post (100).

Images