CN112285617A

CN112285617A - Transformer electrical fault early warning system and device

Info

Publication number: CN112285617A
Application number: CN202011144939.7A
Authority: CN
Inventors: 陈功; 顾绍山; 季萍萍
Original assignee: Nanjing Gubei Electric Technology Co ltd
Current assignee: Nanjing Gubei Electric Technology Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2021-01-29

Abstract

The invention discloses an electric fault early warning system of a transformer, which comprises a transformer shell, an iron core lead sleeve, an iron core grounding wire, a grounding terminal, a high-frequency sensor, a leakage current sensor, a vibration sensor, a noise sensor and a control unit, wherein the iron core lead sleeve is connected with the grounding terminal through the iron core grounding wire, the high-frequency sensor and the leakage current sensor are sleeved on the iron core grounding wire, the vibration sensor is attached to the transformer shell, and signals of the high-frequency sensor, the leakage current sensor, the vibration sensor and the noise sensor are connected into the control unit through data wires. The invention is practical and simple, can integrate 4 transformer monitoring technologies of high-frequency partial discharge, iron core current and noise monitoring and vibration detection, is suitable for online early warning analysis of electrical faults of the transformer, can also be suitable for comprehensive judgment of electrified detection data of the transformer, and has wide market popularization prospect.

Description

Transformer electrical fault early warning system and device

Technical Field

The invention relates to the technical field of transformers, in particular to a transformer electrical fault early warning system and device.

Background

The transformer is an important primary device of a power grid, and once the transformer fails, a large-area power failure accident of the power grid can be caused. At present, various transformer online monitoring devices and early warning systems are available in the market, and the principles adopted by different devices are different. However, the internal faults of the transformer are complex and various, and the single monitoring sensor can solve the problem of accurate qualitative analysis of the transformer faults. Only by adopting a plurality of monitoring technologies to comprehensively analyze, the internal fault can be accurately determined. However, there is no transformer electrical fault early warning system with different sensors fused, which results in poor effect of various transformer early warning systems in the market and huge investment loss. Therefore, an electrical fault early warning system and device for the transformer are provided.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and provides an electric fault early warning system and device for a transformer.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a transformer electrical fault early warning system, includes transformer housing, iron core lead wire sleeve, iron core earth connection, ground terminal, high frequency sensor, leakage current sensor, vibration sensor, noise sensor and the control unit, iron core lead wire sleeve passes through the iron core earth connection and links to each other with ground terminal, high frequency sensor and leakage current sensor cover are on the iron core earth connection, vibration sensor pastes on transformer housing, high frequency sensor, leakage current sensor, vibration sensor and noise sensor pass through the data line with signal access control unit.

Preferably, the noise sensors surround the transformer shell for one circle, and the distance between every two noise sensors is not more than 2 m.

Preferably, the control unit comprehensively analyzes the collected data and gives an early warning result.

Preferably, the high-frequency sensor is arranged at the upper part of the transformer shell; the leakage current sensor is located at the lower part of the transformer shell.

In addition, in order to achieve the purpose, the invention also provides a transformer electrical fault early warning device which comprises the transformer electrical fault early warning system.

Compared with the prior art, the invention has the beneficial effects that: the invention is practical and simple, can integrate 4 transformer monitoring technologies of high-frequency partial discharge, iron core current and noise monitoring and vibration detection, is suitable for online early warning analysis of electrical faults of the transformer, can also be suitable for comprehensive judgment of electrified detection data of the transformer, and has wide market popularization prospect.

Drawings

FIG. 1 is a schematic view of the structure of the present invention.

In the figure: 1 transformer shell, 2 iron core lead sleeves, 3 iron core grounding wires, 4 grounding terminals, 5 high-frequency sensors, 6 leakage current sensors, 7 vibration sensors, 8 noise sensors and 9 control units.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention provides a technical solution: the utility model provides a transformer electrical fault early warning system, includes transformer housing 1, iron core lead wire sleeve 2, iron core earth connection 3, ground terminal 4, high frequency sensor 5, leakage current sensor 6, vibration sensor 7, noise sensor 8 and the control unit 9, iron core lead wire sleeve 2 links to each other with ground terminal 4 through iron core earth connection 3, high frequency sensor 5 and the cover of leakage current sensor 6 are on iron core earth connection 3, vibration sensor 7 pastes on transformer housing 1, high frequency sensor 5, leakage current sensor 6, vibration sensor 7 and noise sensor 8 pass through the data line with signal access control unit 9.

Specifically, the noise sensors 8 surround the transformer housing 1 for one circle, and the distance between the noise sensors 8 is not more than 2 m.

Specifically, the control unit 9 comprehensively analyzes the 4 collected data and gives an early warning result.

Specifically, the high-frequency sensor 5 is arranged at the upper part of the transformer shell 1; the leakage current sensor 6 is located in the lower part of the transformer housing 1.

Specifically, the vibration sensor 7 is located opposite to the core ground line 3.

By selecting four technologies of transformer high-frequency partial discharge monitoring, iron core leakage current detection, transformer space noise monitoring and transformer vibration detection, alarm threshold values of the various technologies in the transformer internal fault monitoring method are respectively researched, on the basis, weight coefficients of the various technologies fused with each other are established, and the transformer electrical fault early warning method for comprehensively analyzing various monitoring indexes is provided.

The working principle in specific implementation is as follows:

the first step is as follows: at least 3 vibration sensors 7 are arranged on a 220kV transformer, at least 2 vibration sensors 7 are arranged on a 500kV single-phase transformer, at least 4 vibration sensors 7 are arranged on a converter transformer, and maximum data in each vibration sensor 7 are extracted to serve as vibration monitoring values of a transformer shell 1;

extracting maximum data in each noise sensor 8 as a monitoring value of the noise in the space around the transformer shell 1;

the second step is that: and extracting a high-frequency partial discharge monitoring signal of the transformer. When the number of discharge pulses is more than 500 or the single discharge pulse is more than 2V, the early warning is defined as level 1; when the number of the discharge pulses is more than 500 and the single discharge pulse is more than 2V, 2-level early warning is defined; when the discharge pulse is larger than 3V or the discharge pulse number is larger than 1000, the early warning is defined as 3-level early warning.

The third step: and extracting a leakage current monitoring signal of the transformer core. When the leakage current of the iron core is more than 500mA, a level 1 early warning is defined; when the leakage current of the iron core is larger than 1000mA, 2-level early warning is defined; when the leakage current of the iron core is larger than 10000mA, the early warning is defined as 3 grades.

The fourth step: and extracting a monitoring signal of the space noise around the transformer. When the space noise of the transformer is greater than 85dB, a level 1 early warning is defined; when the space noise of the transformer is more than 85dB, the odd-even harmonic ratio in the noise signal is less than 1, the frequency energy proportion is more than 0.5, and the spectrum complexity is more than 3, defining the transformer as 2-level early warning; when the space noise of the transformer is more than 95dB or the odd-even sub-harmonic ratio in the noise signal is more than 1, the early warning is defined as 3-level early warning.

The fifth step: and extracting a vibration monitoring signal of the transformer shell. When the vibration value of the transformer shell 1 is larger than 15m/s2, defining as a level 1 early warning; when the vibration value of the transformer shell 1 is larger than 15m/s2, the odd-even harmonic ratio in the vibration signal is smaller than 0.5, the frequency energy ratio is larger than 0.5, and the frequency spectrum complexity is larger than 3, 2-level early warning is defined; when the vibration value of the transformer housing 1 is more than 25m/s2 or the odd-even harmonic ratio in the vibration signal is more than 0.5, a 3-level early warning is defined.

And a sixth step: when the high-frequency partial discharge signal, the iron core leakage current signal, the space noise signal and the shell vibration signal all generate level 1 early warning signals or a level 2 early warning signal is generated in single detection of the four signals, a yellow early warning signal of the transformer is sent out to prompt operation and maintenance personnel to strengthen monitoring;

the seventh step: when 2-level early warning is carried out on a high-frequency partial discharge signal, an iron core leakage current signal, a space noise signal and a shell vibration signal or 3-level early warning signals are carried out in single detection of the four signals, an orange early warning signal of the transformer is sent out to prompt operation and maintenance personnel to strengthen monitoring and timely power off to carry out a diagnostic test;

eighth step: when 3-level early warning is generated on a high-frequency partial discharge signal, an iron core leakage current signal, a space noise signal and a shell vibration signal, a transformer red early warning signal is sent out to prompt operation and maintenance personnel to immediately cut off power and carry out disintegration inspection.

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

Claims

1. The utility model provides a transformer electrical fault early warning system, includes transformer housing (1), iron core lead wire sleeve (2), iron core earth connection (3), ground terminal (4), high frequency sensor (5), leakage current sensor (6), vibration sensor (7), noise sensor (8) and control unit (9), its characterized in that, iron core lead wire sleeve (2) link to each other with ground terminal (4) through iron core earth connection (3), high frequency sensor (5) and leakage current sensor (6) cover are on iron core earth connection (3), vibration sensor (7) paste on transformer housing (1), high frequency sensor (5), leakage current sensor (6), vibration sensor (7) and noise sensor (8) are through data line with signal access control unit (9).

2. The transformer electrical fault early warning system of claim 1, wherein: the noise sensors (8) surround the transformer shell (1) for one circle, and the distance between the noise sensors (8) is not more than 2 m.

3. The transformer electrical fault early warning system of claim 1, wherein: the control unit (9) comprehensively analyzes the 4 collected data and gives an early warning result.

4. The transformer electrical fault early warning system of claim 1, wherein: the mounting position of the high-frequency sensor (5) is positioned at the upper part of the transformer shell (1); the leakage current sensor (6) is positioned at the lower part of the transformer shell (1).

5. A transformer electrical fault early warning device, characterized by comprising a transformer electrical fault early warning system according to any one of claims 1-4.