CN211046477U

CN211046477U - Intelligent controllable overvoltage protection device for neutral point of 110kV transformer

Info

Publication number: CN211046477U
Application number: CN201921933333.4U
Authority: CN
Inventors: 张欣; 张静; 江奕军; 任新卓; 王丽群; 李庆光; 王海龙; 尹哲; 田建军
Original assignee: Beijing Zhongqing Intelligent Technology Co ltd; Hangzhou Power Equipment Manufacturing Co Ltd
Current assignee: Beijing Zhongqing Intelligent Technology Co ltd; Hangzhou Power Equipment Manufacturing Co Ltd
Priority date: 2019-11-11
Filing date: 2019-11-11
Publication date: 2020-07-17
Anticipated expiration: 2029-11-11

Abstract

The utility model discloses a controllable formula overvoltage protection device of 110kV transformer neutral point intelligence, its structure includes metal oxide arrester, earthing switch, controller, controllable clearance, the utility model discloses compare with the transformer protection of other forms, because the quick on-state characteristic of metal oxide arrester, change the insulation of protection transformer neutral point, simultaneously, the closure and the disconnection in clearance are controllable, can prevent that relay protection device from taking place the maloperation. The controllable gap is closed when power frequency overvoltage occurs to the neutral point of the transformer, the arrester is prevented from being damaged or exploding, the voltage threshold of the controller is easy to determine, the gap action time is shorter, the metal oxide arrester is easier to protect, and the transformer is effectively grounded flexibly and conveniently due to the additionally arranged grounding switch.

Description

Intelligent controllable overvoltage protection device for neutral point of 110kV transformer

Technical Field

The utility model relates to a controllable formula overvoltage protection device of 110kV transformer neutral point intelligence belongs to transformer protection technical field.

Background

In China, a 3-66 kV power system adopts a non-effective grounding mode, and a neutral point of a 110-750 kV power system adopts an effective grounding mode. In order to limit the short-circuit current of a single-phase earth fault, prevent communication interference and facilitate setting configuration of relay protection, in an effective grounding system of a neutral point of a 110kV transformer, partial neutral points of the transformer often adopt an ungrounded operation mode. When a circuit has unidirectional grounding fault, non-full-phase operation and lightning overvoltage, the neutral point of the transformer substation which is not grounded bears large overvoltage. Therefore, for a 110kV transformer with a neutral point not operating with earth, necessary overvoltage protection measures are required.

At present, the neutral point of a 110kV ungrounded transformer in China is protected by a single rod gap, a single zinc oxide arrester and a parallel connection of a gapless zinc oxide arrester and a rod-rod gap, but the problem of protecting the neutral point of the transformer is not well solved by several modes.

For single rod gap protection, under the action of lightning impulse, gap breakdown generates wave interception, and the insulation of a neutral point of a transformer can be endangered; in addition, in actual operation, because the protection gap can not self-extinguish arc, the value and time of the grounding current exceed the fixed value of the zero sequence protection, and the relay protection misoperation is caused.

For the protection of a single metal oxide arrester, the arrester is easy to damage or explode when power frequency overvoltage occurs in a system and the action value of the arrester is reached.

For the parallel protection of the gapless metal oxide arrester and the rod-rod gap, the matching requirements of the arrester protection level, the rod gap action characteristic and the insulation level of the neutral point of the transformer are very strict, the realization is very difficult, and the arrester or the gap malfunction is easily caused in the practical application.

The 110kV transformer is applied in a large quantity in a power grid, the neutral point protection device and the protection method of the transformer have certain inherent defects, and in order to improve the safe and stable operation level of a power grid system, a novel device which is higher in reliability and suitable for neutral point overvoltage protection of the 110kV transformer is invented.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model aims at providing a controllable formula overvoltage protection device of 110kV transformer neutral point intelligence to solve 110kV transformer neutral point overvoltage protection's reliability and equipment safety's problem.

In order to achieve the above purpose, the present invention is realized by the following technical solution: the utility model provides a 110kV transformer neutral point intelligence controllable formula overvoltage protection device, its structure includes metal oxide arrester, earthing switch, controller, controllable clearance, metal oxide arrester, earthing switch, controllable clearance belong to primary high-voltage equipment, connect in parallel between transformer neutral point and ground, controllable clearance control is closed after, realize insulating and the protection of metal oxide arrester to transformer neutral point, the transformer neutral point voltage is gathered in real time to the controller, and when voltage was higher than preset threshold value, control controllable clearance 4 and close fast to realize the protection to transformer neutral point insulation and metal oxide arrester, earthing switch is as the effective means of transformer neutral point ground connection, closes earthing switch when the transformer needs effective ground connection operation or overhaul.

Further, the metal oxide lightning arrester is used for conducting automatically under lightning and operation overvoltage to limit the voltage of a neutral point of the transformer and protect the insulation level of the neutral point of the transformer, the rated voltage is not lower than 60kV, and the continuous operation voltage is not lower than 48 kV.

Furthermore, the controllable gap is closed when the power frequency overvoltage of the neutral point of the transformer passes through, the metal oxide lightning arrester is prevented from being damaged or exploding, the rated voltage is not lower than 35kV, and the rated current is not lower than 400A.

Furthermore, the grounding switch is used for effectively grounding when the running mode of the transformer needs to be changed or the transformer needs to be overhauled, and the rated voltage is not lower than 72.5 kV.

Further, the controller is used for detecting the voltage of the neutral point of the transformer in real time, and when the voltage is larger than a preset threshold value, the controllable gap is controlled to be closed, so that the neutral point insulation of the transformer and the metal oxide lightning arrester are reliably protected.

Furthermore, the metal oxide lightning arrester mainly comprises a tank body, a basin-type insulator, an installation base, a core body and the like.

Further, the grounding switch is of a single-phase closed type and is sealed in the aluminum shell.

Furthermore, the controller mainly comprises a box body and a control circuit board.

Advantageous effects

The utility model relates to a controllable formula overvoltage protection device of 110kV transformer neutral point intelligence compares with single stick clearance protection, and this application contains the metal oxide arrester, because the quick on-state characteristic of arrester, changes the insulation of protection transformer neutral point, and simultaneously, the closure in clearance is controllable with the disconnection, can prevent relay protection device emergence maloperation.

Compare with single metal oxide arrester protection, the controllable clearance of this application is closed when power frequency overvoltage takes place at transformer neutral point, prevents the damage or the explosion of arrester.

Compared with the gapless metal oxide arrester and the rod-rod gap parallel protection, the voltage threshold of the controller is easy to determine, and the protection of the metal oxide arrester is easier to realize.

Compared with the metal oxide lightning arrester and the controllable switch parallel protection in other forms, the gap action time is faster, and the grounding switch is additionally arranged, so that the transformer is effectively grounded more flexibly and conveniently.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a schematic structural diagram of an intelligent controllable overvoltage protection device for a 110kV transformer neutral point of the present invention;

FIG. 2 is a schematic diagram of the main wiring principle of the device of the present invention;

fig. 3 is a flow chart of the lightning arrester protection of the utility model;

FIG. 4 is a flow chart of the controller and the protection of the controllable gap according to the present invention;

fig. 5 is the utility model relates to a controllable formula overvoltage protection device of 110kV transformer neutral point intelligence looks sideways at structural schematic.

In the figure: a metal oxide arrester-1, a grounding switch-2, a controller-3 and a controllable gap-4.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand, the present invention is further described below with reference to the following embodiments.

Referring to fig. 1-4, the present invention provides a technical solution: the utility model provides a 110kV transformer neutral point intelligence controllable formula overvoltage protection device, its structure includes metal oxide arrester 1, earthing switch 2, controller 3, controllable clearance 4, metal oxide arrester 1, earthing switch 2, controllable clearance 4 belong to primary high-voltage equipment, connect in parallel between transformer neutral point and ground, controllable clearance 4 control is closed after, realize insulating and metal oxide arrester 1's protection to transformer neutral point, controller 3 gathers transformer neutral point voltage in real time, and when voltage was higher than preset threshold value, control controllable clearance 4 and close fast to realize insulating and metal oxide arrester 1's protection to transformer neutral point, earthing switch 2 is as the effective means of transformer neutral point ground connection, closes earthing switch 2 when the transformer needs effective ground connection operation or maintenance, metal oxide arrester 1 is used for switching on by oneself under thunder and operation overvoltage to restrict transformer 1 The neutral point voltage protects the insulation level of the neutral point of the transformer, the rated voltage is not lower than 60kV, the continuous operation voltage is not lower than 48kV, the controllable gap 4 is used for being closed when the power frequency overvoltage of the neutral point of the transformer passes, the metal oxide arrester 1 is prevented from being damaged or exploded, the rated voltage is not lower than 35kV, the rated current is not lower than 400A, the grounding switch 2 is used for effectively grounding when the transformer needs to change the operation mode or overhaul, the rated voltage is not lower than 72.5kV, the controller 3 is used for detecting the voltage of the neutral point of the transformer in real time, the controllable gap 4 is controlled to be closed when the voltage is greater than a preset threshold value, the insulation of the neutral point of the transformer and the metal oxide arrester 1 are reliably protected, the metal oxide arrester 1 mainly comprises a tank body, a basin-type insulator, a mounting base, a core body and, and the controller 3 is sealed in an aluminum shell and mainly comprises a box body and a control circuit board.

According to the characteristics of the metal oxide arrester 1, when the voltage of a neutral point of a transformer exceeds the voltage of a conduction inflection point of the transformer, the arrester is automatically conducted, so that the insulation level of the transformer is protected; fig. 4 is a protection flowchart of the controller 3 and the controllable gap 4, when the controller 3 detects that the voltage of the neutral point of the transformer exceeds the preset voltage threshold for a certain time, the controller 3 controls the controllable gap 4 to be conducted, so as to prevent the lightning arrester from being damaged or exploding.

For example: compare with single stick clearance protection, this application contains metal oxide arrester 1, because the quick on-state characteristic of arrester, changes the insulation of protection transformer neutral point, and simultaneously, the closure and the disconnection in clearance are controllable, can prevent relay protection device and take place the maloperation.

Compare with single metal oxide arrester protection, controllable clearance 4 of this application is closed when power frequency overvoltage takes place at transformer neutral point, prevents the damage or the explosion of arrester.

Compared with the gapless metal oxide arrester and the rod-rod gap parallel protection, the voltage threshold of the controller 3 is easy to determine, and the protection of the metal oxide arrester 1 is easier to realize.

Compared with the metal oxide arrester and the controllable switch parallel protection in other forms, the gap action time is faster, and the grounding switch 2 is additionally arranged, so that the transformer is effectively grounded more flexibly and conveniently.

The utility model provides a problem be 110kV transformer neutral point overvoltage protection's reliability and equipment safety, the utility model discloses a mutual combination of above-mentioned parts, because the quick on-state characteristic of arrester, change the insulation of protection transformer neutral point, and simultaneously, the closure and the disconnection in clearance are controllable, can prevent relay protection device from taking place the malfunction, controllable clearance is closed when power frequency overvoltage takes place at transformer neutral point, prevent the damage or the explosion of arrester, controller voltage threshold value is confirmed easily, change the protection of realizing the metal oxide arrester, clearance action time is faster, and additionally arranged earthing switch, make the effective ground connection of transformer nimble more convenient.

The basic principles and the main features of the invention and the advantages of the invention have been shown and described above, it will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, but that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a controllable formula overvoltage protection device of 110kV transformer neutral point intelligence, its structure includes metal oxide arrester (1), earthing switch (2), controller (3), controllable clearance (4), its characterized in that:

the metal oxide lightning arrester (1), the grounding switch (2) and the controllable gap (4) belong to primary high-voltage equipment and are connected between a transformer neutral point and the ground in parallel, after the controllable gap (4) is controlled to be closed, insulation of the transformer neutral point and protection of the metal oxide lightning arrester (1) are achieved, the controller (3) collects voltage of the transformer neutral point in real time, when the voltage is higher than a preset threshold value, the controllable gap (4) is controlled to be closed quickly, therefore insulation of the transformer neutral point and protection of the metal oxide lightning arrester (1) are achieved, the grounding switch (2) serves as an effective means of grounding of the transformer neutral point, and the grounding switch (2) is closed when the transformer needs effective grounding operation or maintenance.

2. The intelligent controllable overvoltage protection device for the neutral point of the 110kV transformer as claimed in claim 1, wherein: the metal oxide lightning arrester (1) is used for self-conducting under lightning and operation overvoltage to limit the voltage of a neutral point of a transformer and protect the insulation level of the neutral point of the transformer, the rated voltage is not lower than 60kV, and the continuous operation voltage is not lower than 48 kV.

3. The intelligent controllable overvoltage protection device for the neutral point of the 110kV transformer as claimed in claim 1, wherein: the controllable gap (4) is used for being closed when the power frequency overvoltage of the neutral point of the transformer passes through, the metal oxide lightning arrester (1) is prevented from being damaged or exploded, the rated voltage is not lower than 35kV, and the rated current is not lower than 400A.

4. The intelligent controllable overvoltage protection device for the neutral point of the 110kV transformer as claimed in claim 1, wherein: the grounding switch (2) is used for effectively grounding when the running mode of the transformer needs to be changed or the transformer needs to be overhauled, and the rated voltage is not lower than 72.5 kV.

5. The intelligent controllable overvoltage protection device for the neutral point of the 110kV transformer as claimed in claim 1, wherein: the controller (3) is used for detecting the voltage of the neutral point of the transformer in real time, and controlling the controllable gap (4) to be closed when the voltage is larger than a preset threshold value, so that the neutral point insulation of the transformer and the metal oxide lightning arrester (1) are reliably protected.