Active suppression method and system for background noise of partial discharge ultrahigh frequency signal

Abstract

The invention provides an active suppression method and system for partial discharge ultrahigh frequency signal background noise. The method comprises the following steps: determining the arrangement positions of an ultrahigh frequency sensor and a noise sensor on the outer wall of a GIS (Gas Insulated Switchgear); collecting a partial discharge signal of the mixed noise through an ultrahigh frequency sensor; after the minimum collection period of the noise signals is determined, the noise signals are collected through a noise sensor; inputting the collected noise signal into a spectrum analyzer for spectrum analysis; extracting an obvious narrow-band noise frequency band in a frequency domain, and determining the frequency band and phase jitter of the narrow-band noise frequency band; and active suppression of the narrow-band noise is carried out on the frequency band with the narrow-band noise through the suppression formula of the narrow-band noise interference. According to the invention, the technical problem that the accuracy and the reliability of interference suppression are restricted due to poor narrow-band interference applicability of partial discharge ultrahigh-frequency signals of GIS equipment in a field environment is solved.

Description

Technical Field

[0001] The invention relates to the field of ultra-high frequency sensor calibration and interference suppression, and in particular to a method and system for actively suppressing background noise of a partial discharge ultra-high frequency signal. Background Art

[0002] Partial discharge is the main cause of insulation degradation of electrical equipment and an important indicator of insulation degradation. In order to ensure the safety of the overall operation of the system, partial discharge detection of electrical equipment is required, among which ultra-high frequency partial discharge detection is widely used due to its advantages such as high sensitivity and precise positioning. However, under actual working conditions, due to wear and corrosion of ultra-high frequency sensors and noise interference from the substation environment, the accuracy and sensitivity of receiving partial discharge signals may be affected, resulting in failure to detect and warn in time after electrical equipment fails, resulting in serious consequences. Therefore, it is necessary to calibrate the sensors regularly.

[0003] Under actual working conditions, when calibrating UHF sensors, the accuracy and reliability of the calibration results are often significantly reduced due to the influence of complex background noise. These noise interferences may come from equipment operation, environmental factors or other electromagnetic activities. In order to ensure timely warning of equipment failure, these background noises must be detected to identify the type and characteristics of the noise. This method studies the active suppression method of narrowband noise interference, which can provide a basis for the calibration method of UHF sensors in noise-affected environments.

[0004] The existing invention patent application document with publication number CN118759321A is entitled "A method for on-site detection and laboratory reproduction of background noise of partial discharge ultra-high frequency signals". The existing method includes: determining the arrangement position of the ultra-high frequency sensor on the outer wall of the GIS tube according to the shape of the GIS tube; arranging the ultra-high frequency sensor at the arrangement position of the outer wall of the GIS tube; controlling the ultra-high frequency sensors at various locations to detect the background noise of the partial discharge ultra-high frequency signal of the GIS tube, and reproducing the noise under on-site conditions in the laboratory through signal processing and the arrangement of each noise sensor. However, the aforementioned existing scheme focuses on the collection of all types of noise on site and experimental reproduction, and does not consider denoising-related issues, and cannot achieve the removal of narrow-band interference on site.

[0005] The existing invention patent application document "A GIS ultra-high frequency partial discharge online monitoring system and its monitoring method" with publication number CN109782139A, the existing monitoring system includes a sensor array unit, a waveform signal acquisition and transmission unit, and a host computer unit. The host computer unit includes a signal processing and filtering module, a partial discharge judgment module, and a partial discharge positioning module. The local positioning module includes a distance calculation module and a space positioning module. The monitoring method includes: collecting the background noise during GIS operation through the sensor array unit; the oscilloscope obtains the waveform and sends it to the host computer unit; the host computer unit calculates the partial discharge threshold, and monitors the subsequent waveform data according to the threshold; when there are multiple component amplitudes greater than the threshold in a set of waveform data, it is determined that partial discharge occurs; the waveform data is analyzed by the variable time window method, the waveform distortion time is calculated and the time delay is obtained, and then the hyperbolic equation group is solved by the Newton iteration method to obtain the partial discharge position, and an alarm is issued. The aforementioned existing scheme focuses on the variable time window method in MATLAB to determine whether partial discharge occurs and locate it. This existing technology is difficult to perform denoising operations when noise and partial discharge exist at the same time on site.

[0006] The existing public document "Study on Interference Suppression and Data Transmission of GIS Local Discharge Monitoring System" studies the interference suppression method of GIS local discharge monitoring system, and proposes to use the discharge template windowing and translation method to suppress the ground noise interference in the GIS local discharge monitoring system. The collected local discharge signal without noise is transformed by FFT through Matlab, and the transformed frequency domain signal is used as the discharge template; then, the local discharge signal with ground noise interference is compared with the discharge template, and the minimum value of the two is retained; finally, the processed frequency domain signal is transformed by IFFT, so that the interference is suppressed and the characteristics of the local discharge signal are enhanced. This existing document compares the pure and noisy signal spectrum diagrams, and uses the IFFT method for denoising. However, this existing technology cannot remove narrowband noise in a targeted manner.

[0007] This method is different from the existing invention patent application document "A method for on-site detection and laboratory reproduction of background noise of partial discharge ultra-high frequency signals" with publication number CN118759321A in that the patent is mainly aimed at the collection and experimental reproduction of all types of noise on site, and does not consider the denoising related issues. This patent is aimed at removing narrowband interference on site.

[0008] This method is different from the existing invention patent application document "A GIS UHF partial discharge online monitoring system and monitoring method thereof" with publication number CN109782139A in that the patent is mainly aimed at determining whether partial discharge occurs and locating it by using the variable time window method in MATLAB. This patent is aimed at denoising when there is noise and partial discharge at the same time on site.

[0009] The difference between this method and the existing open document "Research on Interference Suppression and Data Transmission of GIS Partial Discharge Monitoring System" is that the document compares the pure and noisy signal spectra and uses the IFFT method for denoising. However, this patent considers the properties of the GIS equipment itself and the comparison of the partial discharge signal of the noise signal and the mixed noise, and uses the denoising formula to remove the narrowband noise in a targeted manner by determining the narrowband noise frequency band.

[0010] In summary, the existing technology has the technical problem of poor applicability to narrowband interference of partial discharge UHF signals of GIS equipment in field environments, which restricts the accuracy and reliability of interference suppression. Summary of the invention

[0011] The technical problem to be solved by the present invention is to solve the technical problem that the local discharge ultra-high frequency signal of GIS equipment in the field environment has poor applicability to narrowband interference in the prior art, which restricts the accuracy and reliability of interference suppression.

[0012] The present invention adopts the following technical solutions to solve the above technical problems. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals includes:

[0013] S1. Under the field environment, a first UHF sensor and a second UHF sensor are arranged on the outer wall of the GIS pipe, a Gaussian pulse is injected into the first UHF sensor to stimulate the first UHF sensor to send a partial discharge signal, and the partial discharge UHF signal of the mixed background noise of the GIS pipe is detected and saved to obtain the average value of the partial discharge UHF signal of the mixed background noise;

[0014] S2. Arrange a noise sensor on the outer wall of the GIS pipe, use the noise sensor to detect and save the background noise signal of the GIS pipe, and process it to obtain the average value of the background noise signal;

[0015] S3, using a noise sensor to collect noise signals, perform spectrum analysis on the noise signals, determine narrowband noise, and determine the frequency band range of the narrowband noise; determine the phase jitter of the narrowband noise in each frequency band range;

[0016] S4. When the spectrum analysis confirms that the noise signal is narrowband noise, determine and store the frequency band and phase jitter of the narrowband noise, and process them to obtain a background noise suppression formula;

[0017] S5. Using the background noise suppression formula, integrating and processing to obtain background noise suppression waveform data, and saving the background noise suppression waveform data in the host computer;

[0018] S6. Mixing and processing the partial discharge ultra-high frequency signal mixed with background noise and the background noise suppression waveform data to obtain a denoised partial discharge ultra-high frequency signal.

[0019] The present invention considers an active suppression strategy for narrowband interference of partial discharge UHF signals of GIS equipment in a field environment, which can avoid the influence of complex background noise when calibrating UHF sensors, and improve the accuracy and reliability of calibration results and interference suppression operations. The present invention can remove narrowband interference on site. Specifically, the present invention performs denoising in the case where noise and partial discharge exist at the same time on site.

[0020] In a more specific technical solution, in S1, according to a preset layout position and layout distance, a first UHF sensor and a second UHF sensor are arranged on the outer wall of the GIS pipe, and the first UHF sensor and the second UHF sensor are set on a horizontal line.

[0021] In a more specific technical solution, in S1, a Gaussian pulse is injected into the first UHF sensor to stimulate the first UHF sensor to emit a partial discharge signal;

[0022] Control the second UHF sensor to detect the partial discharge UHF signal mixed with the background noise of the GIS tube;

[0023] The partial discharge ultra-high frequency signal is stored in the host computer and processed to obtain the average value U2 of the partial discharge ultra-high frequency signal mixed with background noise.

[0024] Since the noise interference in the prior art comes from equipment operation, environmental factors or other electromagnetic activities, the present invention detects the above background noise, identifies the type and characteristics of the noise, and ensures timely warning of equipment failure.

[0025] In a more specific technical solution, in S2, a noise sensor is arranged at the installation position of the second UHF sensor.

[0026] In a more specific technical solution, in S2, the noise sensor is controlled to detect the background noise signal of the GIS pipe;

[0027] The background noise signal is saved in the host computer and processed to obtain the average value U1 of the background noise signal.

[0028] In a more specific technical solution, in S3, a noise sensor is used to collect noise signals according to the following logic:

[0029]

[0030] In the formula, t represents the acquisition time;

[0031] Perform spectrum analysis on the noise signal. If the peak value of the frequency band in the image obtained by spectrum analysis is significantly higher than the peak value of the white noise in the whole frequency band, and the noise amplitude of the remaining frequency bands is similar to the amplitude of the white noise in the whole frequency band, it is confirmed that narrowband noise exists in the frequency band, and the frequency band range of the narrowband noise is confirmed;

[0032] The spectrum analyzer is used to test and determine the phase jitter of narrowband noise in each frequency band.

[0033] The present invention studies the active suppression method of narrowband noise interference, which can provide a basis for the calibration method of ultra-high frequency sensors in noise-affected environments. The present invention considers the properties of the GIS equipment itself and the comparison of the partial discharge signal of the noise signal and the mixed noise, and then uses the denoising formula to remove the narrowband noise in a targeted manner by determining the narrowband noise frequency band.

[0034] In a more specific technical solution, in S4, if the spectrum analysis confirms that the noise signal is narrow-band noise, the frequency bands f1, f2, ..., f of the narrow-band noise are determined. n 、Phase jitter φ1(t), φ2(t)…φ n (t), where n is the maximum number of narrowband noise frequency bands;

[0035] Set the frequency band f1, f2…f n 、Phase jitter φ1(t), φ2(t)…φ n (t) is saved in the host computer and processed to obtain the background noise suppression formula.

[0036] In a more specific technical solution, the background noise suppression formula is expressed using the following logic:

[0037]

[0038] In the formula, U1 represents the average value of the signal received by the noise sensor; U2 represents the average value of the signal received by the second UHF sensor; a represents the outer diameter of the conductor inside the GIS tube; b represents the inner diameter of the GIS tube shell; V represents the voltage level of the GIS tube.

[0039] In a more specific technical solution, in S6, the following logic is used to process and obtain the denoised partial discharge ultra-high frequency signal k(t):

[0040] k(t)=f(t)+g(t)

[0041] Wherein, f(t) represents the partial discharge UHF signal mixed with narrowband noise measured by the second UHF sensor.

[0042] In a more specific technical solution, the active suppression system of the partial discharge UHF signal background noise includes:

[0043] The partial discharge UHF signal detection module is used to arrange the first UHF sensor and the second UHF sensor in the field environment, inject Gaussian pulses into the first UHF sensor, stimulate the first UHF sensor to send out partial discharge signals, detect and save the partial discharge UHF signal of the mixed background noise of the GIS tube, and obtain the average value of the partial discharge UHF signal of the mixed background noise;

[0044] A background noise signal detection module is used to arrange noise sensors, use the noise sensors to detect and save the background noise signals of the GIS pipe, and process to obtain the average value of the background noise signals. The background noise signal detection module is connected to the partial discharge ultra-high frequency signal detection module;

[0045] The spectrum analysis module is used to collect noise signals using noise sensors, perform spectrum analysis on the noise signals, determine narrowband noise, and determine the frequency range of the narrowband noise; determine the phase jitter of the narrowband noise in each frequency range;

[0046] A background noise suppression logic determination module is used to determine and store the frequency band and phase jitter of the narrowband noise when the spectrum analysis confirms that the noise signal is narrowband noise, and to process and obtain a background noise suppression formula based on the frequency band and phase jitter, and the background noise suppression logic determination module is connected to the spectrum analysis module;

[0047] An integration processing module is used to obtain background noise suppression waveform data by integration processing using a background noise suppression formula, and store the background noise suppression waveform data in a host computer. The integration processing module is connected to the background noise suppression logic determination module;

[0048] The mixing processing module is used to mix and process the partial discharge ultra-high frequency signal mixed with background noise and the background noise suppression waveform data to obtain the denoised partial discharge ultra-high frequency signal. The mixing processing module is connected with the integration processing module and the background noise signal detection module.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] The present invention takes into account an active suppression strategy for narrowband interference of partial discharge UHF signals of GIS equipment in a field environment, which can avoid the influence of complex background noise when calibrating UHF sensors, and improve the accuracy and reliability of calibration results and interference suppression operations.

[0051] Since the noise interference in the prior art comes from equipment operation, environmental factors or other electromagnetic activities, the present invention detects the above background noise, identifies the type and characteristics of the noise, and ensures timely warning of equipment failure.

[0052] The present invention studies the active suppression method of narrowband noise interference, and can provide a basis for the calibration method of ultra-high frequency sensors in an environment affected by noise.

[0053] The present invention solves the technical problem in the prior art that the local discharge ultra-high frequency signal for GIS equipment in a field environment has poor applicability to narrowband interference, which restricts the accuracy and reliability of interference suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic diagram of the basic steps of the method for actively suppressing the background noise of a partial discharge ultra-high frequency signal according to Embodiment 1 of the present invention;

[0055] Figure 2 This is a schematic diagram of the configuration of a UHF sensor according to Embodiment 1 of the present invention;

[0056] Figure 3 This is a schematic diagram of the noise sensor configuration according to Embodiment 1 of the present invention;

[0057] Figure 4 This is a schematic diagram of a partial discharge ultra-high frequency Gaussian pulse signal according to Embodiment 1 of the present invention;

[0058] Figure 5 The spectrum diagram of the background noise signal measured by the noise sensor in the field test of Example 1 of the present invention after spectrum analysis;

[0059] Figure 6 It is a phase diagram of the background noise signal measured by the noise sensor in the field test of Example 1 of the present invention after spectrum analysis. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] Example 1

[0062] like Figure 1 As shown, the method for actively suppressing the background noise of the partial discharge ultra-high frequency signal provided by the present invention comprises the following basic steps:

[0063] Step S1, in a field environment, arrange a first UHF sensor and a second UHF sensor at the outer wall of a GIS pipe, inject a Gaussian pulse into the first UHF sensor to excite it to emit a partial discharge signal, detect and save the partial discharge UHF signal of the mixed background noise of the GIS pipe, and obtain an average value of the partial discharge UHF signal of the mixed background noise;

[0064] like Figure 2 As shown, in the field environment test of this embodiment, a first UHF sensor is arranged on the outer wall at a distance of l1 from any port of the GIS pipe, and a second UHF sensor is arranged on the outer wall at a distance of l2 from the first UHF sensor, so that the first UHF sensor and the second UHF sensor are on a horizontal line, and the first UHF sensor is injected with Figure 4 The Gaussian pulse shown in the figure excites it to emit a partial discharge signal, where l1 is 200mm and l1 is 1000mm. The second UHF sensor is controlled to detect the partial discharge UHF signal of the mixed background noise of the GIS tube, and the data is saved in the host computer, and the average value U2 of the partial discharge UHF signal of the mixed background noise is obtained through processing.

[0065] Step S2: Figure 3 As shown, a noise sensor is arranged on the outer wall of the GIS pipe to detect and save the background noise signal of the GIS pipe and obtain the average value of the background noise signal;

[0066] In this embodiment, a noise sensor is arranged at the same position as the second UHF sensor in the aforementioned step S1. The noise sensor is controlled to detect the background noise signal of the GIS pipe, and the data is stored in the host computer, and the average value U1 of the background noise signal is obtained by processing.

[0067] Step S3, using the aforementioned noise sensor to collect noise signals, performing spectrum analysis on the received noise signals, confirming that the noise is narrowband noise, and the frequency band range of the narrowband noise; determining the phase jitter of the narrowband noise in each frequency band range;

[0068] In this embodiment, the noise signal is collected by a noise sensor, and the collection time is t, where:

[0069]

[0070] like Figure 5 , Figure 6 As shown, in this embodiment, the received noise signal is subjected to spectrum analysis. If the image obtained by the spectrum analysis has a relatively high peak value in one or more frequency bands and the noise amplitudes in the remaining frequency bands are similar to the amplitude of the white noise in the full frequency band, the noise is confirmed to be narrowband noise, and the frequency band range of the narrowband noise is confirmed. The phase jitter of the narrowband noise in each frequency band range is determined by spectrum analyzer testing.

[0071] Step S4: when the spectrum analysis confirms that the collected noise is narrowband noise, determine and store the frequency band and phase jitter of the narrowband noise;

[0072] In this embodiment, if the spectrum analysis confirms that the collected noise is narrow-band noise, the frequency bands f1, f2, ..., f of the narrow-band noise are determined. n and phase jitter φ1(t), φ2(t)…φn (t), n takes the maximum number of narrowband noise frequency bands, and saves the data in the host computer. The background noise suppression formula is obtained:

[0073]

[0074] Among them, U1 represents the average value of the signal received by the noise sensor; U2 represents the average value of the signal received by the second UHF sensor; a represents the outer diameter of the conductor inside the GIS tube; b represents the inner diameter of the GIS tube shell; V represents the voltage level of the GIS tube.

[0075] Step S5, calculating and integrating to obtain background noise suppression waveform data, and saving the waveform in the host computer;

[0076] Step S6, mixing the partial discharge UHF signal mixed with background noise obtained in the above step S2 with the background noise suppression waveform stored in the host computer in step S5 to obtain a denoised partial discharge UHF signal k(t).

[0077] k(t)=f(t)+g(t)

[0078] Wherein, f(t) represents the partial discharge UHF signal mixed with narrowband noise measured by the second UHF sensor.

[0079] In summary, the present invention considers an active suppression strategy for narrowband interference of local discharge UHF signals of GIS equipment in field environments, which can avoid the influence of complex background noise when calibrating UHF sensors, and improve the accuracy and reliability of calibration results and interference suppression operations.

[0080] Since the noise interference in the prior art comes from equipment operation, environmental factors or other electromagnetic activities, the present invention detects the above background noise, identifies the type and characteristics of the noise, and ensures timely warning of equipment failure.

[0081] The present invention studies the active suppression method of narrowband noise interference, and can provide a basis for the calibration method of ultra-high frequency sensors in an environment affected by noise.

[0082] The present invention solves the technical problem in the prior art that the local discharge ultra-high frequency signal for GIS equipment in a field environment has poor applicability to narrowband interference, which restricts the accuracy and reliability of interference suppression.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for actively suppressing background noise of partial discharge ultra-high frequency signals, characterized in that: The method comprises: S1. Under the field environment, a first UHF sensor and a second UHF sensor are arranged on the outer wall of the GIS pipe, a Gaussian pulse is injected into the first UHF sensor to stimulate the first UHF sensor to send a partial discharge signal, and the partial discharge UHF signal of the mixed background noise of the GIS pipe is detected and saved to obtain the average value of the partial discharge UHF signal of the mixed background noise; S2, arranging a noise sensor, using the noise sensor to detect and save the background noise signal of the GIS pipe, and processing to obtain an average value of the background noise signal; S3, using the noise sensor to collect noise signals, perform spectrum analysis on the noise signals, perform narrowband noise determination, and determine the frequency band range of the narrowband noise; determine the phase jitter of the narrowband noise in each frequency band range; S4. When the spectrum analysis confirms that the noise signal is the narrowband noise, determine and store the frequency band of the narrowband noise and the phase jitter, and process them to obtain a background noise suppression formula; S5, using the background noise suppression formula, integrating and processing to obtain background noise suppression waveform data, and storing the background noise suppression waveform data in the host computer; S6. Mixing the partial discharge UHF signal mixed with background noise and the background noise suppression waveform data to obtain a denoised partial discharge UHF signal.

2. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S1, the first UHF sensor and the second UHF sensor are arranged on the outer wall of the GIS tube according to a preset arrangement position and a preset arrangement distance, and the first UHF sensor and the second UHF sensor are arranged on a horizontal line.

3. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S1, the Gaussian pulse is injected into the first UHF sensor to stimulate the first UHF sensor to emit a partial discharge signal; Controlling the second UHF sensor to detect the partial discharge UHF signal mixed with the background noise of the GIS tube; The partial discharge ultra-high frequency signal is stored in a host computer, and processed to obtain an average value U2 of the partial discharge ultra-high frequency signal of the mixed background noise.

4. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S2, the noise sensor is arranged at the installation position of the second UHF sensor.

5. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S2, controlling the noise sensor to detect the background noise signal of the GIS pipe; The background noise signal is stored in a host computer and processed to obtain an average value U1 of the background noise signal.

6. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S3, the noise signal is collected by using the noise sensor according to the following logic: In the formula, t represents the acquisition time; Performing spectrum analysis on the noise signal, if the peak value of the frequency band of the image obtained by the spectrum analysis is significantly higher than the peak value of the white noise in the whole frequency band, and the noise amplitudes of the remaining frequency bands are similar to the amplitude of the white noise in the whole frequency band, then it is confirmed that narrowband noise exists in the frequency band, and the frequency band range of the narrowband noise is confirmed; A spectrum analyzer is used to perform a test to determine the phase jitter of the narrowband noise in each frequency band.

7. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S4, if the spectrum analysis confirms that the noise signal is the narrowband noise, the frequency bands f1, f2, ..., f of the narrowband noise are determined. n , the phase jitter φ1(t), φ2(t)…φ n (t), where n is the maximum number of narrowband noise frequency bands; The frequency bands f1, f2...f n , the phase jitter φ1(t), φ2(t)…φ n (t) The background noise suppression formula is obtained by processing the background noise suppression formula in the host computer.

8. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 7, characterized in that: The background noise suppression formula is expressed using the following logic: In the formula, U1 represents the average value of the signal received by the noise sensor; U2 represents the average value of the signal received by the second UHF sensor; a represents the outer diameter of the conductor inside the GIS tube; b represents the inner diameter of the GIS tube shell; V represents the voltage level of the GIS tube.

9. The method for actively suppressing the background noise of partial discharge ultra-high frequency signals according to claim 1, characterized in that: In S6, the following logic is used to process and obtain the denoised partial discharge UHF signal k(t): k(t)=f(t)+g(t) Wherein, f(t) represents the partial discharge UHF signal mixed with narrowband noise measured by the second UHF sensor.

10. Active suppression system for partial discharge UHF signal background noise, characterized in that: The system comprises: The partial discharge UHF signal detection module is used to arrange the first UHF sensor and the second UHF sensor in the field environment, inject Gaussian pulses into the first UHF sensor, stimulate the first UHF sensor to send a partial discharge signal, detect and save the partial discharge UHF signal of the mixed background noise of the GIS tube, and obtain the average value of the partial discharge UHF signal of the mixed background noise; A background noise signal detection module is used to arrange a noise sensor, use the noise sensor to detect and save the background noise signal of the GIS tube, and process to obtain an average value of the background noise signal. The background noise signal detection module is connected to the partial discharge ultra-high frequency signal detection module; A spectrum analysis module, used to collect noise signals using the noise sensor, perform spectrum analysis on the noise signals, perform narrowband noise determination, and determine the frequency band range of the narrowband noise; determine the phase jitter of the narrowband noise in each frequency band range; A background noise suppression logic determination module, used for determining and storing the frequency band and the phase jitter of the narrowband noise when the spectrum analysis confirms that the noise signal is the narrowband noise, and processing and obtaining a background noise suppression formula based on the frequency band and the phase jitter, wherein the background noise suppression logic determination module is connected to the spectrum analysis module; An integration processing module, used for integrating and processing the background noise suppression formula to obtain background noise suppression waveform data, and storing the background noise suppression waveform data in the host computer, wherein the integration processing module is connected to the background noise suppression logic determination module; A mixing processing module is used to mix and process the partial discharge ultra-high frequency signal of the mixed background noise and the background noise suppression waveform data to obtain a denoised partial discharge ultra-high frequency signal. The mixing processing module is connected to the integration processing module and the background noise signal detection module.

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