Integrated comprehensive on-line monitoring device for transformer

Abstract

The utility model discloses an integrated comprehensive on-line monitoring device for a transformer, which comprises a shell and is characterized in that a chromatography sensing mechanism, a partial discharge detection mechanism and a winding temperature detection mechanism are arranged in the shell, and the chromatography sensing mechanism comprises a stepping motor (1). The working end of the stepping motor (1) is connected with a piston (3) movably connected in an air cylinder (2) through a lead screw, an inner cavity of the air cylinder (2) is respectively communicated with an oil-gas separation device (6) and a chromatographic column (8) through a first pipeline (4) and a second pipeline (5), a first one-way valve is arranged on the first pipeline (4), a second one-way valve (10) is arranged on the second pipeline (5), and the first one-way valve (10) is connected with the piston (3). Gas in the oil-gas separation device (6) can enter the air cylinder (2), and gas in the air cylinder (2) can enter the chromatographic column (8).

Description

Technical Field

[0001] This utility model relates to the field of transformer testing, and in particular to an integrated online monitoring device for transformers. Background Technology

[0002] Faults in oil-immersed transformers are typically initially caused by partial discharge due to insulation problems, which then gradually manifest as increased dissolved gas concentration in the transformer oil, decreased insulation performance, and rising winding temperatures, ultimately leading to serious faults or even fires. To address these issues, power systems have deployed various monitoring devices: chromatography is the most widely used method for detecting dissolved gas concentration in oil, fluorescence is the most accurate and reliable method for oil temperature detection, and ultra-high frequency sensors are the most sensitive for detecting partial discharge. However, these different functional detection devices all require independent sensing units, housings, communication systems, human-machine interfaces, and backend systems, resulting in low space utilization and difficulties in coordinating their operation.

[0003] Meanwhile, while gas chromatography is the most reliable testing method, it has a relatively short lifespan. Frequent sampling can severely reduce its lifespan, while reducing the sampling frequency makes it difficult to detect problems in a timely manner, thus presenting certain limitations.

[0004] Therefore, a method or apparatus is needed to solve the above problems. Summary of the Invention

[0005] This invention addresses the aforementioned shortcomings of existing technologies by proposing an integrated online monitoring device that features a simple structure, ingenious design, and reasonable layout, thereby improving transformer fault detection efficiency, substation equipment installation space utilization, and the lifespan of gas chromatographs.

[0006] The technical solution of this utility model is: an integrated online monitoring device for transformers, comprising a housing, characterized in that: a chromatographic sensing mechanism, a partial discharge detection mechanism, and a winding temperature detection mechanism are disposed within the housing.

[0007] The chromatographic sensing mechanism includes a stepper motor 1. The working end of the stepper motor 1 is connected to a piston 3 movably connected inside a cylinder 2 via a lead screw. The inner cavity of the cylinder 2 is connected to an oil-gas separation device 6 and a chromatographic column 8 via a first pipeline 4 and a second pipeline 5, respectively. A first one-way valve is installed on the first pipeline 4, and a second one-way valve is installed on the second pipeline 5. Gas from the oil-gas separation device 6 can enter the cylinder 2, and gas from the cylinder 2 can enter the chromatographic column 8.

[0008] The partial discharge detection mechanism includes a high-frequency antenna 9, which is connected to a data acquisition card 11 via a signal amplifier 10.

[0009] The winding temperature detection mechanism includes an ultraviolet light diode 12. A beam splitter 13 is arranged in the emission direction of the ultraviolet light diode 12, and an energy fiber 14 is arranged in the transmission direction of the beam splitter 13. An fiber end cap 15 is provided at the end of the energy fiber 14. The fiber end cap 15 is a semi-closed quartz tube structure filled with temperature-sensitive phosphor 16. A photodetector 17 is arranged in the reflection direction of the beam splitter 13. The photodetector 17 is also connected to the data acquisition card 11 through a signal amplifier 10.

[0010] The monitoring device also includes an industrial control computer 18, which is electrically connected to the chromatographic column 8, data acquisition card 11 and ultraviolet light diode 12 in the chromatographic sensing mechanism. At the same time, the data acquisition card 11 is also electrically connected to the chromatographic column 8.

[0011] The gain band of the high-frequency antenna 9 is 300-1500MHz.

[0012] The ultraviolet light diode 12 can emit light with a wavelength of 390-430nm.

[0013] Compared with the prior art, this utility model has the following advantages:

[0014] This integrated online monitoring device for transformers features a simple structure, ingenious design, and reasonable layout. Addressing the problem of traditional transformer testing requiring different instruments for different parameters, it employs a unique structure. Within its casing, it houses three distinct detection mechanisms, organically integrated rather than simply summed up. The partial discharge detection and winding temperature detection mechanisms transmit data to the industrial control computer via a data acquisition card. A high-frequency partial discharge sensor, combined with winding temperature detection, serves as a predictive condition for transformer faults. The device categorizes transformer operating states into different levels and sets the sampling frequency of dissolved gases in the oil according to these levels. This achieves the goal of detecting dissolved gases in the oil using chromatographic sensors while reducing their usage frequency, thus extending their lifespan. This monitoring device improves transformer fault detection efficiency, substation equipment installation space utilization, and the lifespan of gas chromatographs. Furthermore, its simple manufacturing process and low production cost make it highly advantageous and suitable for widespread application in this field, with a promising market prospect. Attached Figure Description

[0015] Figure 1 This is a system composition diagram of an embodiment of the present utility model.

[0016] Figure 2This is a schematic diagram of the chromatographic sensing mechanism in an embodiment of this utility model. Detailed Implementation

[0017] The specific embodiments of this utility model will be described below with reference to the accompanying drawings. Figure 1 , Figure 2 As shown: An integrated online monitoring device for transformers includes a housing as a base, within which are installed a chromatographic sensing mechanism, a partial discharge detection mechanism, and a winding temperature detection mechanism.

[0018] The chromatographic sensing mechanism includes a stepper motor 1. The working end of the stepper motor 1 is connected to a piston 3 movably connected inside a cylinder 2 via a lead screw. The inner cavity of the cylinder 2 is connected to an oil-gas separation device 6 and a chromatographic column 8 via a first pipeline 4 and a second pipeline 5, respectively. A first one-way valve is installed on the first pipeline 4, and a second one-way valve is installed on the second pipeline 5. Gas from the oil-gas separation device 6 can enter the cylinder 2, and gas from the cylinder 2 can enter the chromatographic column 8.

[0019] The partial discharge detection mechanism includes a high-frequency antenna 9, which is connected to a data acquisition card 11 via a signal amplifier 10.

[0020] The winding temperature detection mechanism includes an ultraviolet light diode 12. A beam splitter 13 is arranged in the emission direction of the ultraviolet light diode 12, and an energy fiber 14 is arranged in the transmission direction of the beam splitter 13. An fiber end cap 15 is provided at the end of the energy fiber 14. The fiber end cap 15 is a semi-closed quartz tube structure filled with temperature-sensitive phosphor 16. A photodetector 17 is arranged in the reflection direction of the beam splitter 13. The photodetector 17 is also connected to the data acquisition card 11 through a signal amplifier 10.

[0021] The monitoring device also includes an industrial control computer 18, which is electrically connected to the chromatographic column 8, data acquisition card 11 and ultraviolet light diode 12 in the chromatographic sensing mechanism. At the same time, the data acquisition card 11 is also electrically connected to the chromatographic column 8.

[0022] The gain band of the high-frequency antenna 9 is 300-1500MHz.

[0023] The ultraviolet light diode 12 can emit light with a wavelength of 390-430nm.

[0024] The working process of the integrated online monitoring device for transformers in this embodiment of the utility model is as follows: The high-frequency antenna 9 can monitor the high-frequency electromagnetic waves (frequency range between 300MHz and 1500MHz) generated during partial discharge of the transformer in real time and continuously. It can convert such high-frequency electromagnetic waves into synchronous output voltage signals. The signal amplifier 10 can amplify the output voltage signal generated after the high-frequency antenna 16 senses the electromagnetic waves of partial discharge. The output voltage of the signal amplifier 10 is sampled by the data acquisition card 11, and the sampling results are input into the industrial control computer 18 to calculate the spectrum and decibel of the electromagnetic waves in order to determine the intensity and number of partial discharges and the discharge type.

[0025] The ultraviolet light emitted by the ultraviolet photodiode 12, with a wavelength of 390-430 nm, enters the energy fiber 14 through the beam splitter 13 and is transmitted to the fiber end cap 15 at its tail. Since the fiber end cap 15 is a semi-closed quartz tube structure filled with temperature-sensitive phosphor 16, the ultraviolet light, after reaching the phosphor 16, returns to red fluorescence in the 600-700 nm wavelength range after a certain relaxation time t. The returned fluorescence signal returns to the beam splitter 13 through the energy fiber 14. Due to the difference between the output and returned wavelengths, the beam splitter 13 reflects the returned light to the photodetector 17.

[0026] The photocurrent output by the photodetector 17 is amplified by the signal amplifier 10. The industrial control computer 18 collects and calculates the time difference of the returned light signal through the data acquisition card 11, and calculates the relaxation time t. The relaxation time t and the temperature of the phosphor have a unique negative correlation coefficient, so the transformer winding temperature T can be accurately measured.

[0027] By setting an alarm value for the transformer winding temperature T, the transformer winding temperature status is divided into three different levels: normal, overheating, and severe overheating. At the same time, by setting multiple alarm values ​​for excessive partial discharge intensity, the transformer partial discharge status is divided into three different levels: normal, slight, and severe discharge. The industrial control computer 18 will then dynamically adjust the operating frequency of the chromatography sensor mechanism according to the discharge status of the transformer. In other words, the chromatography column 8 will only operate at short time intervals under specific conditions (typically 12 hours), while under other conditions it will operate at long time intervals (typically once a week). This effectively reduces the operating frequency of the chromatography column 8, thereby improving its service life.

[0028] The oil-gas separation device 6 can separate the dissolved gas in the transformer oil into a gaseous state in a certain proportion through vacuum or oscillation. It separates the oil sample in the transformer into oil and gas. The stepper motor 1 drives the piston 3 to move, and the gas separated by the oil-gas separation device 6 is drawn into the inner cavity of the cylinder 2 through the first pipeline 4. After enough gas to be tested is drawn into the cylinder 2, the stepper motor 1 drives the piston 3 to move in the opposite direction. The gas to be tested is sent into the chromatographic column 8 through the second pipeline 5. The voltage signal output by the sensitive element in the chromatographic column 8 is detected by the data acquisition card 15, and a chromatogram is plotted and the gas concentration is analyzed.

Claims

1. An integrated online monitoring device for transformers, comprising a housing, characterized in that: The housing is equipped with a chromatography sensing mechanism, a partial discharge detection mechanism, and a winding temperature detection mechanism. The chromatographic sensing mechanism includes a stepper motor (1). The working end of the stepper motor (1) is connected to a piston (3) movably connected in a cylinder (2) via a lead screw. The inner cavity of the cylinder (2) is connected to the oil-gas separation device (6) and the chromatographic column (8) via a first pipeline (4) and a second pipeline (5), respectively. A first one-way valve is provided on the first pipeline (4) and a second one-way valve is provided on the second pipeline (5). Gas in the oil-gas separation device (6) can enter the cylinder (2) and gas in the cylinder (2) can enter the chromatographic column (8). The partial discharge detection mechanism includes a high-frequency antenna (9), which is connected to a data acquisition card (11) via a signal amplifier (10). The winding temperature detection mechanism includes an ultraviolet light diode (12), a beam splitter (13) is arranged in the emission direction of the ultraviolet light diode (12), an energy fiber (14) is arranged in the transmission direction of the beam splitter (13), and an optical fiber end cap (15) is arranged at the end of the energy fiber (14). The optical fiber end cap (15) is a semi-closed quartz tube structure, which is filled with temperature-sensitive phosphor (16). A photodetector (17) is arranged in the reflection direction of the beam splitter (13). The photodetector (17) is also connected to the data acquisition card (11) through a signal amplifier (10). The monitoring device also includes an industrial control computer (18), which is electrically connected to the chromatographic column (8), data acquisition card (11) and ultraviolet light diode (12) in the chromatographic sensing mechanism. At the same time, the data acquisition card (11) is also electrically connected to the chromatographic column (8).

2. The integrated online monitoring device for transformers according to claim 1, characterized in that: The gain band of the high-frequency antenna (9) is 300-1500MHz.

3. The integrated online monitoring device for transformers according to claim 1, characterized in that: The ultraviolet light diode (12) can emit light with a wavelength of 390-430nm.

Images