A method for detecting and reproducing background noise of partial discharge high frequency signal in situ and in laboratory

Abstract

The application discloses a method for detecting and reproducing partial discharge ultrahigh frequency signal background noise in situ. The method comprises the following steps: determining the arrangement position of an ultrahigh frequency sensor on the outer wall of a GIS pipe according to the shape of the GIS pipe; arranging the ultrahigh frequency sensor at the arrangement position on the outer wall of the GIS pipe; controlling the ultrahigh frequency sensor to detect the partial discharge ultrahigh frequency signal background noise of the GIS pipe; and reproducing the noise in a laboratory under the in-situ condition through signal processing and arrangement of each noise sensor. The application considers the sensor arrangement mode suitable for GIS pipes with different shapes and under in-situ conditions, and ensures the accuracy of the in-situ background noise test and the reliability of the reproduced noise signal in the laboratory.

Description

Technical Field

[0001] This invention relates to the field of partial discharge detection technology, and in particular to a method for on-site detection and laboratory reproduction of background noise in ultra-high frequency partial discharge signals. Background Technology

[0002] Partial discharge signals are early signs of potential insulation faults in high-voltage electrical equipment, typically indicating aging or damage to insulation materials, and are a key early warning indicator for the reliability and safety of power systems. Ultra-high frequency (UHF) partial discharge detection technology is widely used in the field of partial discharge detection due to its high detection sensitivity and ability to locate partial discharge sources. However, under actual operating conditions, the sensitivity and other performance indicators of UHF sensors may decline due to factors such as wear, leading to serious consequences such as delayed equipment fault warnings. Therefore, regular calibration of UHF sensors is necessary.

[0003] However, in actual operating conditions, the calibration of UHF sensors is often affected by complex background noise. This noise may originate from equipment operation, environmental factors, or other electromagnetic activities, significantly reducing the accuracy and reliability of sensor calibration techniques. Therefore, it is necessary to detect the background noise affecting UHF sensors in the field to identify the type and characteristics of the noise, and to reproduce it in the laboratory, laying the foundation for further research on sensor calibration methods under the influence of noise. Summary of the Invention

[0004] This invention provides a method for on-site detection and laboratory reproduction of background noise in UHF partial discharge signals, in order to solve the problem of inaccurate detection of background noise in UHF partial discharge signals in the prior art.

[0005] Firstly, a method for on-site detection of background noise in partial discharge ultra-high frequency signals is provided, including:

[0006] Based on the shape of the GIS pipe, determine the placement position of the UHF sensor on the outer wall of the GIS pipe;

[0007] The ultra-high frequency sensor is arranged at the designated location on the outer wall of the GIS pipe;

[0008] Each of the ultra-high frequency sensors is controlled to detect the background noise of the partial discharge ultra-high frequency signal of the GIS pipe.

[0009] Secondly, a laboratory method for reproducing background noise of a partial discharge ultra-high frequency signal is provided, including:

[0010] In the method for detecting background noise of partial discharge UHF signals described in the first aspect, a noise sensor is arranged at the location where the GIS tube is arranged.

[0011] The amplitude of the background noise of the partial discharge UHF signal of the GIS tube detected by each UHF sensor in the method for detecting background noise of partial discharge UHF signal in the first aspect is multiplied by a scaling factor according to the frequency band range to obtain the amplitude of the reproduced noise signal of each UHF sensor.

[0012] The amplitude of the reproduced noise signal of each of the noise sensors is controlled to reproduce the background noise of the partial discharge UHF signal by each of the UHF sensors arranged in the same position.

[0013] Thus, this embodiment of the invention takes into account sensor arrangement methods suitable for GIS pipes of different shapes and field environments, ensuring the accuracy of background noise field testing and the reliability of noise signal reproduction in the laboratory. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart of the method for detecting background noise of UHF partial discharge signals according to Embodiment 1 of the present invention;

[0016] Figure 2 This is a flowchart of the method for reproducing background noise of a partial discharge ultra-high frequency signal according to Embodiment 2 of the present invention;

[0017] Figure 3 This is a schematic diagram showing the arrangement of the ultra-high frequency sensor in the straight cylindrical GIS pipe according to Embodiment 1 of the present invention;

[0018] Figure 4 This is a schematic diagram showing the arrangement of the ultra-high frequency sensor in the L-shaped GIS pipe according to Embodiment 1 of the present invention;

[0019] Figure 5 This is a schematic diagram showing the arrangement of the ultra-high frequency sensor in the T-shaped GIS pipe according to Embodiment 1 of the present invention;

[0020] Figure 6 This is a schematic diagram illustrating the determination of the unit attenuation of a UHF signal using a straight cylindrical GIS pipe according to Embodiment 1 of the present invention.

[0021] Figure 7 This is a schematic diagram illustrating the determination of the unit attenuation of a UHF signal using an L-shaped GIS tube according to Embodiment 1 of the present invention.

[0022] Figure 8This is a schematic diagram showing the arrangement of the noise sensor in the straight cylindrical GIS pipe according to Embodiment 2 of the present invention;

[0023] Figure 9 This is a schematic diagram showing the arrangement of the noise sensor in the L-shaped GIS pipe according to Embodiment 2 of the present invention;

[0024] Figure 10 This is a schematic diagram showing the arrangement of the noise sensor in the T-shaped GIS pipe according to Embodiment 2 of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] Embodiment 1 of this invention discloses a method for detecting background noise in partial discharge ultra-high frequency signals. This detection method can be applied in the field. Figure 1 As shown, the method of this embodiment of the invention includes the following steps:

[0028] Step S101: Determine the placement position of the UHF sensor on the outer wall of the GIS pipe according to its shape.

[0029] Specifically, depending on the shape of the GIS pipe, this step may include the following three processes:

[0030] I. For example Figure 3 As shown, the GIS pipe is cylindrical in shape.

[0031] 1. If the GIS pipe is cylindrical, the reference point for determining the GIS pipe is the center of the outer wall of the GIS pipe.

[0032] 2. Determine the first preset number of arrangement positions on the outer walls on both sides of the GIS pipe's reference point.

[0033] The placement locations and reference points are all located on the central axis of the outer wall of the GIS pipe. It should be understood that the placement locations are all located on the same side of the GIS pipe.

[0034] The distance between two adjacent placement positions is as follows:

[0035] l=λ1e k-1 .

[0036] Where l is the distance between two adjacent sensor locations. k is the attenuation coefficient at the corner of the GIS pipe, which can be set empirically, for example, k = 1. λ1 is the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the GIS pipe.

[0037] The first preset quantity can be set based on experience; for example, the first preset quantity is 3.

[0038] II. Figure 4 As shown, the GIS pipe is L-shaped.

[0039] 1. If the GIS pipe is L-shaped, and the GIS pipe is formed by connecting the first pipe and the second pipe, the reference point for determining the GIS pipe is the intersection of the central axes of the outer walls of the first pipe and the second pipe.

[0040] 2. Determine the reference point of the GIS pipe as the layout location, and determine a second preset number of layout locations on the outer walls of the first and second pipes of the L-shaped GIS pipe.

[0041] The first pipeline is positioned on a central axis parallel to its outer wall, and the second pipeline is positioned on a central axis parallel to its outer wall. It should be understood that both pipelines are located on the same side of the GIS pipe.

[0042] The distance between two adjacent placement positions is as follows:

[0043]

[0044] Where l is the distance between two adjacent sensor locations. k is the attenuation coefficient at the corner of the GIS pipe, which can be set empirically, for example, k = 1.4. λ2 is the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the first pipe, and λ3 is the unit attenuation of the partial discharge UHF signal along the central axis of the outer side of the second pipe.

[0045] The second preset quantity can be set based on experience; for example, the second preset quantity can be 2. Thus, including the reference point, there are a total of 5 placement positions.

[0046] III. Figure 5 As shown, the GIS pipe is T-shaped.

[0047] 1. If the GIS pipe is T-shaped, and the GIS pipe is formed by connecting the first pipe and the second pipe, then the reference point for determining the GIS pipe is the intersection of the central axes of the outer walls of the first pipe and the second pipe.

[0048] 2. Determine the reference point of the GIS pipe as the layout position, and determine a third preset number of layout positions on three sides of the reference points on the outer walls of the first pipe and the second pipe of the T-shaped GIS pipe.

[0049] Among them, the layout position and the reference point of the first pipe are located on the central axis parallel to the outer wall of the first pipe, and the layout position and the reference point of the second pipe are located on the central axis parallel to the outer wall of the second pipe. It should be understood that the layout positions are all on the same side of the GIS pipe. In this way, assuming that the first pipe is the "-" of the T shape and the second pipe is the "|" of the T shape, the reference point is on the first pipe, and there are a third preset number of layout positions on each side of the reference point on the first pipe, and there are a third preset number of layout positions on the second pipe.

[0050] Among them, the distance between two adjacent layout positions is as follows:

[0051]

[0052] Among them, l is the distance between two adjacent layout positions. V is the voltage level of the GIS pipe, with the unit of kV. k is the structure index of the GIS pipe, which can be set according to experience. For example, k = 1.6. λ2 is the unit attenuation amount of the partial discharge UHF signal along the central axis direction of the outer wall of the first pipe of the GIS pipe, and λ3 is the unit attenuation amount of the partial discharge UHF signal along the central axis direction of the outer wall of the second pipe of the GIS pipe.

[0053] Among them, the third preset number can be set according to experience. For example, the third preset number is 1. In this way, including the reference point, there are a total of 4 layout positions.

[0054] Step S102: Arrange UHF sensors at the layout positions on the outer wall of the GIS pipe.

[0055] Step S103: Control each UHF sensor to detect the background noise of the partial discharge UHF signal of the GIS pipe.

[0056] During detection, the detection time can be preset, and a section of noise signal within the detection time can be collected. For example, the preset detection time is 10s. The detected results can be stored in the upper computer.

[0057] Preferably, before step S101, according to the different shapes of the GIS pipe, the following two processes can be used to determine the corresponding unit attenuation amount of the partial discharge UHF signal: [[ID=!29]]

[0058] 1. The shape of the GIS pipe is a straight cylinder <##

[0059] 1. If the GIS pipe is cylindrical, a first UHF sensor is arranged on the outer wall at a first preset distance from any port of the GIS pipe, a second UHF sensor is arranged on the outer wall at a second preset distance from the first UHF sensor, and a third UHF sensor is arranged on the outer wall at a second preset distance from the second UHF sensor, so that the first UHF sensor, the second UHF sensor and the third UHF sensor are located sequentially on the central axis of the outer wall of the GIS pipe.

[0060] The above settings are as follows Figure 6 As shown. The first and second preset distances can be set based on experience; for example, the first preset distance is 200mm and the second preset distance is 1000mm.

[0061] 2. Excite the first UHF sensor to transmit a signal, and process the maximum amplitude of the signal received by the second UHF sensor and the maximum amplitude of the signal received by the third UHF sensor according to the attenuation formula to obtain the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the GIS pipe.

[0062] The formula for attenuation is as follows:

[0063]

[0064] Where U2 is the maximum amplitude of the signal received by the second UHF sensor, and U3 is the maximum amplitude of the signal received by the third UHF sensor.

[0065] II. GIS pipes are L-shaped or T-shaped.

[0066] 1. If the GIS pipe is L-shaped or T-shaped, and the GIS pipe is formed by connecting the first pipe and the second pipe to form an L-shaped or T-shaped structure, then a fourth UHF sensor is arranged on the outer wall of the first pipe at a third preset distance from the port of the first pipe, a fifth UHF sensor is arranged on the outer wall of the first pipe at a fourth preset distance from the fourth UHF sensor, and a sixth UHF sensor is arranged on the outer wall of the first pipe at a fourth preset distance from the fifth UHF sensor, so that the fourth UHF sensor, the fifth UHF sensor and the sixth UHF sensor are located sequentially on the central axis of the outer wall of the first pipe.

[0067] 2. A seventh UHF sensor is arranged on the outer wall of the second pipe at a fourth preset distance from the intersection of the central axis of the outer wall of the first pipe and the second pipe, and an eighth UHF sensor is arranged on the outer wall of the second pipe at a fourth preset distance from the seventh UHF sensor, so that the intersection, the seventh UHF sensor and the eighth UHF sensor are located sequentially on the central axis of the outer wall of the second pipe.

[0068] Taking an L-shaped GIS pipe as an example, the above settings are as follows: Figure 7As shown. The third and fourth preset distances can be set based on experience; for example, the third preset distance is 200mm and the fourth preset distance is 1000mm.

[0069] 3. Excite the fourth UHF sensor to transmit a signal. Process the maximum amplitude of the signal received by the fifth UHF sensor and the maximum amplitude of the signal received by the sixth UHF sensor according to the attenuation formula to obtain the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the first pipe. Process the maximum amplitude of the signal received by the seventh UHF sensor and the amplitude of the signal received by the eighth UHF sensor according to the attenuation formula to obtain the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the second pipe.

[0070]

[0071] U5 represents the maximum amplitude of the signal received by the fifth UHF sensor, and U6 represents the maximum amplitude of the signal received by the sixth UHF sensor.

[0072]

[0073] U7 represents the maximum amplitude of the signal received by the seventh UHF sensor, and U8 represents the maximum amplitude of the signal received by the eighth UHF sensor.

[0074] Furthermore, repeated experiments revealed that the λ1 of the straight-tube GIS pipe is almost identical to the λ2 of the L-shaped and T-shaped GIS pipes, and the λ3 of the L-shaped and T-shaped GIS pipes is almost identical. Therefore, in practical applications, the λ1 of the straight-tube GIS pipe can be used as λ2.

[0075] As shown in Table 1, the noise acquisition rates obtained by using the method of Embodiment 1 of the present invention and the conventional point-spotting method of the prior art are as follows. It can be seen from Table 1 that the noise acquisition rate of the method of the present invention is higher and can obtain UHF signals more accurately.

[0076] Table 1 Noise Collection Rate

[0077]

[0078] Example 2

[0079] Embodiment 2 of this invention discloses a laboratory method for reproducing background noise of a partial discharge ultra-high frequency signal. For example... Figure 2 As shown, the method specifically includes the following steps:

[0080] Step S201: In the method for detecting background noise of partial discharge UHF signals, a noise sensor is placed at the location where the GIS tube is arranged.

[0081] The method for detecting background noise of the partial discharge UHF signal is the same as that described in Example 1, and will not be repeated here. The placement positions are as follows: Figures 8-10 As shown.

[0082] Step S202: Multiply the amplitude of the partial discharge UHF signal background noise of the GIS tube detected by each UHF sensor in the partial discharge UHF signal background noise detection method by a scaling factor according to the frequency band range to obtain the amplitude of the reproduced noise signal of each UHF sensor.

[0083] Specifically, the formula for calculating the amplitude of the reproduced noise signal is as follows:

[0084] f n ′=k f ·f n .

[0085] Among them, f n ′ represents the amplitude of the reproduced noise signal of the nth ultra-high frequency sensor. k f This is a scaling factor, which can be set empirically. For example, if the noise frequency range is below 300kHz, k... f Take 0.8. If the noise frequency range is above 300kHz, k f Take 1.4. f n This represents the amplitude of the background noise of the partial discharge UHF signal of the GIS pipe detected by the nth UHF sensor. The UHF sensors can be numbered sequentially from one end, for example, from left to right.

[0086] Step S203: Control each noise sensor to reproduce the background noise of the partial discharge UHF signal according to the amplitude of the reproduced noise signal of each UHF sensor with the same arrangement position.

[0087] Specifically, the host computer can be connected to the signal conditioning module, and the signal conditioning module can be connected to the noise sensor to control the noise sensor to reproduce the noise signal.

[0088] In summary, the embodiments of the present invention take into account sensor arrangement methods suitable for GIS pipes of different shapes and field environments, ensuring the accuracy of background noise field testing and the reliability of noise signal reproduction in the laboratory.

[0089] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting background noise in a partial discharge ultra-high frequency signal, characterized in that, include: Based on the shape of the GIS pipe, determine the placement position of the UHF sensor on the outer wall of the GIS pipe; The ultra-high frequency sensor is arranged at the designated location on the outer wall of the GIS pipe; Control the ultra-high frequency sensors at various locations to detect the background noise of the partial discharge ultra-high frequency signal of the GIS pipe; If the GIS pipe is cylindrical, then the reference point of the GIS pipe is determined to be the center of the outer wall of the GIS pipe; A first preset number of arrangement positions are determined on both sides of the GIS pipe reference point; Wherein, the arrangement position and the reference point are both located on the central axis of the outer wall of the GIS pipe, and the distance between two adjacent sensor arrangement positions is... Where l is the distance between two adjacent sensor locations, k is the attenuation coefficient at the corner of the GIS pipe, and λ1 is the unit attenuation of the partial discharge UHF signal along the horizontal direction of the outer wall of the GIS pipe. If the GIS pipe is L-shaped or T-shaped, and the GIS pipe is formed by connecting the first pipe and the second pipe, then the reference point of the GIS pipe is determined to be the intersection of the central axes of the outer side walls of the first pipe and the second pipe. The reference point of the GIS pipe is determined as the arrangement position, and a second preset number of arrangement positions are determined on the outer walls of the first and second pipes of the L-shaped GIS pipe respectively; or, the reference point of the GIS pipe is determined as the arrangement position, and a third preset number of arrangement positions are determined on the outer walls of the first and second pipes of the T-shaped GIS pipe and on each of the three sides of the reference point of the GIS pipe. Wherein, the arrangement position of the first pipe and the reference point are parallel to the central axis of the outer wall of the first pipe, the arrangement position of the second pipe and the reference point are located on the central axis parallel to the outer wall of the second pipe, and the distance between two adjacent sensor arrangement positions is... Where, l is the distance between two adjacent sensor locations, k is the attenuation coefficient at the corner of the GIS pipe, λ2 is the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the first pipe, and λ3 is the unit attenuation of the partial discharge UHF signal along the central axis of the outer wall of the second pipe.

2. The method for detecting background noise of partial discharge UHF signals according to claim 1, characterized in that, Before determining the placement position of the UHF sensor on the outer wall of the GIS pipe, the method for obtaining the unit attenuation includes: If the GIS pipe is cylindrical, a first UHF sensor is arranged on the outer wall at a first preset distance from any port of the GIS pipe, a second UHF sensor is arranged on the outer wall at a second preset distance from the first UHF sensor, and a third UHF sensor is arranged on the outer wall at a second preset distance from the second UHF sensor, so that the first UHF sensor, the second UHF sensor and the third UHF sensor are sequentially distributed on the central axis of the outer wall of the GIS pipe; The first UHF sensor is excited to transmit a partial discharge signal. The maximum amplitude of the signal received by the second UHF sensor and the maximum amplitude of the signal received by the third UHF sensor are processed to obtain the unit attenuation of the UHF signal along the central axis of the outer wall of the GIS pipe. U2 is the maximum amplitude of the signal received by the second UHF sensor, and U3 is the maximum amplitude of the signal received by the third UHF sensor.

3. The method for detecting background noise of partial discharge UHF signals according to claim 1, characterized in that, Before determining the placement position of the UHF sensor on the outer wall of the GIS pipe, the method for obtaining the unit attenuation includes: If the GIS pipe is L-shaped or T-shaped, the GIS pipe will be formed by connecting the first pipe and the second pipe to form an L-shape or T-shape. A fourth UHF sensor is arranged on the outer wall of the first pipe at a third preset distance from the port of the first pipe, a fifth UHF sensor is arranged at a fourth preset distance from the fourth UHF sensor, and a sixth UHF sensor is arranged at a fourth preset distance from the fifth UHF sensor, so that the fourth UHF sensor, the fifth UHF sensor and the sixth UHF sensor are sequentially distributed on the central axis of the outer wall of the first pipe. A seventh UHF sensor is arranged at a fourth preset distance from the intersection of the central axes of the first pipe and the outer walls of the second pipe on the outer wall of the second pipe. An eighth UHF sensor is arranged at a fourth preset distance from the seventh UHF sensor on the outer wall of the second pipe, so that the intersection of the central axes, the seventh UHF sensor and the eighth UHF sensor are located sequentially on the central axis of the outer wall of the second pipe. The fourth UHF sensor is excited to transmit a partial discharge signal. The maximum amplitude of the signal received by the fifth UHF sensor and the maximum amplitude of the signal received by the sixth UHF sensor are processed to obtain the unit attenuation of the UHF signal along the central axis direction of the outer wall of the first pipe. Where U5 is the maximum amplitude of the signal received by the fifth UHF sensor, and U6 is the maximum amplitude of the signal received by the sixth UHF sensor; the maximum amplitude of the signal received by the seventh UHF sensor and the maximum amplitude of the signal received by the eighth UHF sensor are processed to obtain the unit attenuation of the UHF signal along the central axis direction of the outer wall of the second pipe. U7 is the maximum amplitude of the signal received by the seventh UHF sensor, and U8 is the maximum amplitude of the signal received by the eighth UHF sensor.

4. A laboratory method for reproducing background noise of a partial discharge ultra-high frequency signal, characterized in that, include: In the method for detecting background noise of partial discharge UHF signals as described in any one of claims 1 to 3, a noise sensor is arranged at the arrangement position of the GIS tube; The amplitude of the background noise of the partial discharge UHF signal of the GIS tube detected by each of the UHF sensors in the method for detecting background noise of partial discharge UHF signal as described in any one of claims 1 to 3 is multiplied by a scaling factor according to the frequency band range to obtain the amplitude of the reproduced noise signal of each noise sensor. The noise sensor is controlled to reproduce the background noise of the partial discharge UHF signal by reproducing the noise signal amplitude of the UHF sensor in the same arrangement position.

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