Transformer fault positioning equipment

Abstract

The utility model provides a transformer fault positioning device which comprises a sampling unit, a control device and an industrial computer which are connected in sequence, and the sampling unit comprises a gas sensitive sensor; the control device comprises a signal conversion unit, a voltage division amplification filter circuit, a processor, a memory, a display module, an RS-232 / 485 serial port and an alarm; the signal conversion unit is connected with the gas sensitive sensor on one hand, and is connected with the processor through the partial pressure amplification filter circuit on the other hand, and the processor is further connected with the memory, the display module, the RS-232 / 485 serial port and the alarm; the signal conversion unit is used for converting an analog signal into a digital signal, and the voltage division amplification filter circuit is used for carrying out voltage division, amplification and filtering processing on the digital signal output by the signal conversion unit; and the control device is connected with the industrial computer through an RS-232 / 485 serial port. According to the utility model, the interference in the signal transmission process is reduced, and the accuracy of the detection result is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of transformers, and in particular relates to a transformer fault locating device. Background Art

[0002] Transformers are a commonly used electrical equipment in power transmission, which are mainly used to transform AC voltage and current to transmit AC power. For large power transformers, oil is almost always used for insulation and heat dissipation. Transformer oil and solid organic insulating materials in the oil will deteriorate and crack into low molecular gas under the operating voltage due to various factors such as electricity, heat, oxidation and local arc. The latent overheating or discharge fault inside the transformer will accelerate the rate of gas production. Therefore, the composition and content of dissolved gas in oil reflect the degree of transformer insulation aging or failure to a certain extent. The method of judging whether there is a potential fault in the transformer in this way is the oil chromatography analysis method. The utility model patent with application number CN201822036145.3 provides a chromatographic analysis device that can accurately locate the transformer. However, when performing online fault diagnosis and positioning, the transmission and processing of the detected digital signal are carried out on site, and good anti-interference measures must be taken to improve the accuracy of the detection. Summary of the invention

[0003] In view of this, the utility model aims to overcome the deficiencies of the above-mentioned problems in the prior art and proposes a transformer fault locating device to reduce interference and improve the reliability and stability of detection.

[0004] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0005] A transformer fault location device comprises a sampling unit, a control device, and an industrial computer connected in sequence, wherein the sampling unit and the control device are arranged at the equipment site, and the industrial computer is arranged in a control room;

[0006] The sampling unit includes a gas sensor;

[0007] The control device includes a signal conversion unit, a voltage-dividing amplifying and filtering circuit, a processor, a memory, a display module, an RS-232 / 485 serial port, and an alarm; the signal conversion unit is connected to the gas sensor on one hand, and is connected to the processor through the voltage-dividing amplifying and filtering circuit on the other hand, and the processor is also connected to the memory, the display module, the RS-232 / 485 serial port, and the alarm; the signal conversion unit is used to convert an analog signal into a digital signal, and the voltage-dividing amplifying and filtering circuit is used to divide, amplify, and filter the digital signal output by the signal conversion unit;

[0008] The control device is connected to the industrial computer via the RS-232 / 485 serial port.

[0009] Furthermore, the gas sensor is connected to the oil-gas separation device to collect the gas signal separated by the oil-gas separation device.

[0010] Furthermore, the signal conversion unit includes an analog multiplexer and an AD converter.

[0011] Furthermore, the signal conversion unit is provided with a sampling and holding circuit, and a zero-drift circuit is also provided between the sampling and holding circuit and the AD converter.

[0012] Furthermore, the voltage-dividing, amplifying and filtering circuit includes a voltage-dividing circuit, an amplifier, and a filtering capacitor.

[0013] Furthermore, the sample-and-hold circuit adopts a LF398 chip.

[0014] Furthermore, the AD converter adopts ADC0809.

[0015] Furthermore, the processor is a single chip microcomputer.

[0016] Furthermore, the alarm is an audible and visual alarm.

[0017] Furthermore, the industrial computer also includes a display and a keyboard.

[0018] Compared with the prior art, the transformer fault location device described in the utility model has the following advantages:

[0019] The utility model reduces interference in the signal transmission process, improves the accuracy of the final detection result, can timely discover and locate faults, has a simple structure, is easy to install, has strong practicality, is safe and reliable, has a high degree of intelligence, has a low equipment cost, and is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of the principle of a transformer fault locating device of the utility model;

[0022] Figure 2 This is a voltage-dividing, amplifying and filtering circuit diagram of the utility model;

[0023] Figure 3 It is a schematic diagram of a sample-and-hold circuit of the utility model;

[0024] Figure 4 It is a schematic diagram of the control device principle of the utility model.

[0025] Description of reference numerals:

[0026] 1-Oil-gas separation device; 2-Gas sensor; 3-Control device; 4-Industrial computer; 5-Signal conversion unit; 6-Voltage divider amplification filter circuit; 7-Memory; 8-Processor; 9-Display module; 10-RS-232 / 485 serial port; 11-Alarm. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0028] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0031] like Figure 1As shown, the utility model provides a transformer fault location device, comprising a sampling unit, a control device 3, and an industrial computer 4 connected in sequence, wherein the sampling unit and the control device 3 are arranged at the equipment site, and the industrial computer 4 is arranged in the control room;

[0032] The sampling unit includes a gas sensor 2;

[0033] like Figure 4 As shown, the control device 3 includes a signal conversion unit 5, a voltage-dividing amplifying and filtering circuit 6, a processor 8, a memory 7, a display module 9, an RS-232 / 485 serial port 10, and an alarm 11; the signal conversion unit 5 is connected to the gas sensor 2 on the one hand, and is connected to the processor 8 through the voltage-dividing amplifying and filtering circuit 6 on the other hand, and the processor 8 is also connected to the memory 7, the display module 9, the RS-232 / 485 serial port 10, and the alarm 11; the signal conversion unit 5 is used to convert an analog signal into a digital signal, and the voltage-dividing amplifying and filtering circuit 6 is used to divide, amplify, and filter the digital signal output by the signal conversion unit;

[0034] The control device 3 is connected to the industrial computer 4 via the RS-232 / 485 serial port 10 .

[0035] Specifically, the gas sensor 2 is connected to the oil-gas separation device 1 and is used to collect the gas signal separated by the oil-gas separation device 1 .

[0036] Specifically, the signal conversion unit 5 includes an analog multiplexer and an AD converter, wherein the analog multiplexer includes an 8-way input switch and a 3-bit address latch decoder, and the 8-way input switch can access 8-way analog input signals.

[0037] like Figure 3 As shown, the signal conversion unit 5 is provided with a sampling and holding circuit, and a zero-drift circuit is further provided between the sampling and holding circuit and the AD converter.

[0038] like Figure 2 As shown, the voltage-dividing, amplifying and filtering circuit 6 includes a voltage-dividing circuit, an amplifier, and a filtering capacitor.

[0039] Generally, the concentration of each component gas in transformer oil is very small, and the measured output signal is small. It will cause attenuation when transmitted through a long signal cable, so it needs to be pre-amplified. The signal output by the sensor and the pre-amplifier circuit is 0-30V. It cannot directly enter the control device after cable transmission, and must be divided before measurement, amplification and filtering. In the utility model, the voltage signal transmitted by the cable is divided by resistors R5 and R6, and then the high-precision, high-input impedance differential amplifier composed of IC1 and IC2 is input into the control device after double-T filtering.

[0040] Specifically, the sample-and-hold circuit uses a LF398 chip.

[0041] Specifically, the AD converter adopts ADC0809.

[0042] Specifically, the processor 8 is a single chip microcomputer.

[0043] Specifically, the alarm 11 is an audible and visual alarm.

[0044] Specifically, the industrial computer 4 also includes a display and a keyboard.

[0045] In order to achieve long-term reliable detection on site, the utility model fully considers the requirements of anti-interference and working stability, and adopts photoelectric isolation technology for the conversion between strong and weak electricity. The oil and gas separation device, signal conversion and control device are placed on site, and the industrial computer is placed in the control room, which reduces the influence of space electromagnetic field interference on the industrial computer when controlling the action of the strong electric part.

[0046] The utility model utilizes the existing oil-gas separation device 1 to separate gas, then utilizes the gas sensor 2 to collect gas data, and transmits the data to the industrial computer 4 through the control device 3. The industrial computer 4 performs chromatographic analysis to accurately locate the transformer fault.

[0047] All matters not mentioned above are prior art.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A transformer fault location device, characterized in that: It comprises a sampling unit, a control device (3), and an industrial computer (4) which are connected in sequence, wherein the sampling unit and the control device (3) are arranged at the equipment site, and the industrial computer (4) is arranged in a control room; The sampling unit comprises a gas sensor (2); The control device (3) comprises a signal conversion unit (5), a voltage-dividing amplifying and filtering circuit (6), a processor (8), a memory (7), a display module (9), an RS-232 / 485 serial port (10), and an alarm (11); the signal conversion unit (5) is connected to the gas sensor (2) on the one hand, and is connected to the processor (8) through the voltage-dividing amplifying and filtering circuit (6) on the other hand; the processor (8) is also connected to the memory (7), the display module (9), the RS-232 / 485 serial port (10), and the alarm (11); the signal conversion unit (5) is used to convert an analog signal into a digital signal, and the voltage-dividing amplifying and filtering circuit (6) is used to perform voltage division, amplification, and filtering on the digital signal output by the signal conversion unit (5); The control device (3) is connected to the industrial computer (4) via an RS-232 / 485 serial port (10).

2. A transformer fault location device according to claim 1, characterized in that: The gas sensor (2) is connected to the oil-gas separation device (1) and is used to collect gas signals separated by the oil-gas separation device (1).

3. A transformer fault location device according to claim 1, characterized in that: The signal conversion unit (5) comprises an analog multiplexer and an AD converter.

4. A transformer fault location device according to claim 3, characterized in that: The signal conversion unit (5) is provided with a sampling and holding circuit, and a zero-point drift circuit is also provided between the sampling and holding circuit and the AD converter.

5. A transformer fault location device according to claim 1, characterized in that The voltage-dividing, amplifying and filtering circuit (6) comprises a voltage-dividing circuit, an amplifier and a filtering capacitor.

6. A transformer fault location device according to claim 4, characterized in that: The sample-and-hold circuit adopts the LF398 chip.

7. A transformer fault location device according to claim 3, characterized in that: The AD converter adopts ADC0809.

8. A transformer fault location device according to claim 1, characterized in that The processor (8) is a single chip microcomputer.

9. A transformer fault location device according to claim 1, characterized in that : The alarm (11) adopts an audible and visual alarm.

10. A transformer fault location device according to claim 1, characterized in that The industrial computer (4) also includes a display and a keyboard.

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