Partial discharge detection anti-interference method, system, medium and device

Abstract

The present application relates to the technical field of partial discharge detection of power equipment, and particularly relates to a partial discharge detection anti-interference method, system, medium and equipment, the method mainly comprising: extracting the frequency spectrum features of the partial discharge original signal based on the partial discharge original signal obtained in the air medium before installation of the interference isolation device; after installation of the interference isolation device with main inductance and distributed sub-inductance, continuously collecting the partial discharge signal and obtaining its characteristic parameters, calculating the signal-to-noise ratio improvement rate and the interference attenuation rate based on the frequency spectrum features and the characteristic parameters, and then adjusting the interference isolation device parameters according to the signal-to-noise ratio improvement rate and the interference attenuation rate. Through the nested structure of "main inductance covering the main interference frequency band + sub-inductance matching the edge interference frequency band", combined with the air gap dynamic adjustment of the magnetic core displacement, the defects of the traditional single inductance "narrow coverage and slow response" are solved, and "full frequency band locking-real-time tracking" of the wide frequency band interference of chirp identification is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of partial discharge detection of power equipment, and particularly relates to a partial discharge detection anti-interference method, system, medium and equipment. BACKGROUND

[0002] In the power system, the partial discharge detection of high-voltage equipment such as transformers and GIS (gas insulated switchgear) is crucial to the safe and stable operation of the power equipment. However, when measuring the partial discharge on the high-voltage side, the partial discharge signals generated by overhead lines will seriously interfere with the measurement results. These interference signals not only affect the accurate extraction of the characteristics of the partial discharge signals, but also may lead to misjudgment, making it impossible to timely and accurately discover the partial discharge faults existing in the high-voltage equipment itself, thereby bringing potential risks to the safe operation of the power system. In the prior art, a single parameter inductor or magnetic ring can only form a high resistance to fixed frequency interference, and cannot cover the wide frequency band interference in the 10 kHz-100 MHz frequency band in the partial discharge detection. Moreover, when the interference frequency drifts, the inductance parameter needs to be manually recalculated and replaced, which has a lagging response, resulting in unstable interference suppression effect. In addition, the traditional fast Fourier transform (FFT) can only identify a single interference center frequency, and it is difficult to capture the edge frequency and bandwidth of the interference, further leading to parameter design deviation of the interference isolation device, affecting the accurate extraction of the characteristics of the partial discharge signals (such as discharge quantity and phase distribution). Therefore, there is an urgent need for an efficient, simple and low-cost method to filter out the partial discharge interference of overhead lines.

[0003] The above information disclosed in the background section is only for the purpose of enhancing the understanding of the background of the present application and therefore can include information that does not constitute the prior art that is already known to those of ordinary skill in the art. SUMMARY

[0004] The present application provides a partial discharge detection anti-interference method, system, medium and equipment, which realizes accurate identification of wide frequency band interference and dynamic optimization of interference isolation device parameters by introducing a chirp signal, solves the problem of incomplete suppression of wide frequency band and non-stationary interference in the prior art, and improves the reliability and effectiveness of partial discharge detection of high-voltage equipment.

[0005] In one aspect, the present application discloses a partial discharge detection anti-interference method, comprising the following steps:

[0006] obtaining a background signal in a state without partial discharge before installation of an interference isolation device, and a partial discharge original signal in an air medium;

[0007] performing fast Fourier transform on the partial discharge original signal to obtain a basic frequency band distribution, and synchronously extracting the frequency spectrum characteristics of the partial discharge original signal;

[0008] The linear chirp reference signal is generated according to the basic frequency band distribution, and the linear chirp reference signal is correlated with the partial discharge original signal;

[0009] The result of the correlation operation is calibrated in combination with the background signal, and the complete frequency band range of the external interference signal affecting the partial discharge detection is determined based on the result of the calibrated correlation operation, wherein the complete frequency band range includes a main interference frequency band and an edge interference frequency band;

[0010] The interference isolation device is installed in series at the connection between the high-voltage equipment and the power transmission line, and the linear chirp reference signal is injected into the measurement loop; wherein the interference isolation device includes a multi-frequency adaptive inductance component, and the multi-frequency adaptive inductance component is a nested adjustable inductance structure, which includes a main inductance and a distributed sub-inductance.

[0011] The partial discharge signal is continuously collected by using the high-voltage side pulse current method, the signal-to-noise ratio improvement rate and the interference attenuation rate are calculated based on the frequency spectrum characteristics and the characteristic parameters of the partial discharge signal, and then the interference isolation device parameters are adjusted according to the signal-to-noise ratio improvement rate and the interference attenuation rate.

[0012] The main interference frequency band is matched by the main inductance parameter, and the edge interference frequency band is matched by the air gap length.

[0013] The linear chirp reference signal is kept real-time frequency sweeping to track the interference frequency drift, and when the chirp signal monitors that the interference frequency drift exceeds 5%, the air gap length is automatically adjusted by the magnetic core displacement mechanism of the sub-inductance, so that the inductance impedance peak value is locked to the frequency after the drift.

[0014] In the partial discharge detection anti-interference method, the main inductance and the sub-inductance in the multi-frequency adaptive inductance component are made of high magnetic permeability material, and the outer wrapping insulation layer is made of high-voltage resistant insulation material; the main inductance is 1, and the sub-inductance is 3-6; all the sub-inductances use gradient magnetic permeability magnetic cores.

[0015] In the partial discharge detection anti-interference method, the response time of the interference isolation device parameter adjustment is ≤1s; the range of the air gap length is 0.1-1mm; the inductance value of the nested adjustable inductance structure can be continuously adjusted.

[0016] In the partial discharge detection anti-interference method, the background signal and the partial discharge original signal before the installation of the interference isolation device are obtained by using a partial discharge test platform, and the partial discharge signal after the installation of the interference isolation device is obtained.

[0017] The background signal and the partial discharge original signal before installation of the interference isolation device and the partial discharge signal after installation of the interference isolation device are collected by a high-frequency current sensor under a coverage frequency band of 10 kHz-100 MHz.

[0018] In the partial discharge detection anti-interference method, the cross-correlation operation further includes:

[0019] A one-to-one correspondence between time and frequency is established through time-frequency mapping analysis, and the frequency resolution of the cross-correlation operation is ensured to be ≤1 kHz, and the identification error of the interference edge frequency is ensured to be ≤0.1 MHz.

[0020] In the partial discharge detection anti-interference method, the interference isolation device further includes: a plurality of multi-frequency band adaptive inductors connected in parallel or in series to form a cascade filter network, wherein the main inductance frequency band difference of adjacent inductors is ≥1 MHz, the sub-inductance frequency band difference is ≥0.5 MHz, the frequency band distribution is based on 10 kHz-100 MHz full-frequency band interference distribution identified by the chirp signal; the impedance of the cascade network to the 50 Hz power frequency signal is ≤5Ω.

[0021] In another aspect, the present application discloses a partial discharge detection anti-interference system, which includes:

[0022] The signal acquisition module, the signal processing module, the interference isolation device and the monitoring optimization module, wherein,

[0023] The signal acquisition module includes a partial discharge test platform, a high-frequency current sensor and a chirp signal generator, wherein,

[0024] The partial discharge test platform includes a partial discharge test platform, a high-frequency current sensor and a chirp signal generator, wherein,

[0025] The high-frequency current sensor is used to collect the background signal and the partial discharge original signal before installation of the interference isolation device and the partial discharge signal after installation of the interference isolation device under a coverage frequency band of 10 kHz-100 MHz;

[0026] The chirp signal generator is used to generate a linear chirp reference signal with a sweep range of 10 kHz-100 MHz and an amplitude of 1 / 100 of the amplitude of the partial discharge original signal;

[0027] The signal processing module is connected to the signal acquisition module, and the signal processing module includes a digital signal processor and a data analysis unit, wherein,

[0028] The digital signal processor is configured to: perform fast Fourier transform on the partial discharge original signal to obtain a basic frequency band distribution, and synchronously extract a frequency spectrum feature of the partial discharge original signal, and perform cross-correlation operation on the partial discharge original signal by using a linear chirp reference signal;

[0029] The data analysis unit is configured to calibrate a result of the cross-correlation operation in combination with the background signal, and determine a complete frequency band range of the external interference signal affecting the partial discharge detection based on the calibrated result of the cross-correlation operation; wherein the complete frequency band range includes a main interference frequency band and an edge interference frequency band.

[0030] The interference isolation device includes a multi-frequency band adaptive inductance component, wherein,

[0031] The multi-frequency band adaptive inductance component is a nested adjustable inductance structure, and the nested adjustable inductance structure includes one main inductance and 3-6 distributed sub-inductances; all the sub-inductances adopt gradient permeability magnetic cores.

[0032] The monitoring optimization module includes a partial discharge monitoring system and a parameter adjustment unit, wherein,

[0033] The partial discharge monitoring system is configured to continuously collect partial discharge signals by using a high-voltage side pulse current method, and calculate a signal-to-noise ratio improvement rate and an interference attenuation rate based on the frequency spectrum feature and a characteristic parameter of the partial discharge signal.

[0034] The parameter adjustment unit is configured to adjust parameters of the interference isolation device according to the signal-to-noise ratio improvement rate and the interference attenuation rate, and keep the linear chirp reference signal real-time frequency sweeping to track the interference frequency drift, wherein,

[0035] The adjusting the parameters of the interference isolation device includes matching the main interference frequency band by a main inductance parameter, and matching the edge interference frequency band by an air gap length.

[0036] When the chirp signal monitors that the interference frequency drift exceeds 5%, a magnetic core displacement mechanism of the sub-inductance automatically adjusts the air gap length within ≤1s, so that the inductance impedance peak value is locked to the frequency after the drift.

[0037] In another aspect, the present application also discloses a computer storage medium, which comprises computer instructions, and when the computer instructions are run on a computer, the computer instructions make the computer execute the method.

[0038] In another aspect, the present application also discloses an electronic device, which comprises:

[0039] The electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein,

[0040] The processor implements the method when executing the program.

[0041] Compared with the prior art, the present application has the following advantages: through 10 kHz-100 MHz linear sweep, the limitation that the traditional FFT can only identify a single fixed frequency is solved, the complete frequency band (including edge frequency) and dynamic drift of the interference are accurately positioned, and the frequency basis for "targeted suppression" of multi-frequency inductance is provided. Through the nested structure of "main inductance covering the main interference frequency band + sub-inductance matching the edge interference frequency band", combined with the dynamic adjustment of the air gap with the displacement of the magnetic core, the defects of the traditional single inductance "narrow coverage and slow response" are solved, and "full-band locking-real-time tracking" of the wide-band interference identified by chirp is realized. In the implementation process of the present application, the device parameters can be adjusted and optimized according to the actual measurement situation to adapt to different interference environments and equipment working conditions, thereby improving the applicability and flexibility of the method. BRIEF DESCRIPTION OF DRAWINGS

[0042] Various other advantages and benefits of the present application will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limiting of the present application. It should be readily understood that the drawings are merely illustrative of the present application and that they, therefore, do not limit its scope, which is set forth in the claims attached hereto. Obviously, other embodiments of the application can be derived from the drawings, without paying creative labor, which will be readily apparent to those skilled in the art. Moreover, in the entire drawings, the same reference numerals have been used to designate the same components.

[0043] In the drawings:

[0044] Figure 1 is a flowchart of the partial discharge measurement anti-interference method in an embodiment of the present application;

[0045] Figure 2 is a structural schematic diagram of a partial discharge test platform in another embodiment of the present application;

[0046] Figure 3 is a partial discharge signal suppression comparison chart after adding an interference isolation device in another embodiment of the present application;

[0047] The reference signs are as follows:

[0048] 1-no partial discharge transformer; 2-current limiting resistor; 3-capacitive voltage divider; 4-oscilloscope; 5-discharge cavity; 6-Rogowski coil; 7-no partial discharge voltage regulator; 8-chirp signal generator.

[0049] The present application will be further explained in conjunction with the drawings and embodiments. DETAILED DESCRIPTION

[0050] The present application will be further explained in conjunction with the drawings and embodiments. Figures 1 to 3The specific embodiments of the present application will now be described in detail with specific reference being made to the figures. While the specific embodiments of the present application are described in the context of a method, it will be understood that the application is not limited to this context and is applicable to any suitable context. It should be noted that the description and drawings merely illustrate the principles of the application. The application should not be construed as limited to the embodiments set forth in the description and drawings, but includes all solutions falling within the scope of the present application.

[0051] It should be noted that certain terms have been used throughout the description and the claims to refer to particular components. As one skilled in the art will appreciate, components can be referred to by different names and can perform different functions without departing from the scope of the application. Accordingly, no significance should be placed upon the names of components, or references thereto, used in the description and the claims. The description and the claims are not to be limited in scope by the embodiments described or illustrated in the description and the claims so long as such embodiments are within the scope of the present application. The description and the claims may

[0052] In order to make the present application clearly understood and easily carried out, the following will further explain and describe the embodiments of the present application with specific examples in conjunction with the accompanying drawings, and each drawing does not constitute a limitation to the embodiments of the present application.

[0053] As shown in Figure 1 The present application discloses a partial discharge detection anti-interference method, comprising the following steps:

[0054] The background signal in the state without partial discharge before installation of the interference isolation device is acquired by a high-frequency current sensor, and the original partial discharge signal in the air medium is acquired;

[0055] Fast Fourier transform is performed on the original partial discharge signal to acquire the basic frequency band distribution, and the frequency spectrum features of the original partial discharge signal are extracted synchronously;

[0056] The linear chirp reference signal is generated according to the basic frequency band distribution, and the cross-correlation operation is performed on the linear chirp reference signal and the original partial discharge signal;

[0057] The result of the cross-correlation operation is calibrated in combination with the background signal, and the complete frequency band range of the external interference signal affecting the partial discharge detection is determined based on the calibrated result of the cross-correlation operation, wherein the complete frequency band range includes the main interference frequency band and the edge interference frequency band;

[0058] The interference isolation device is connected in series at the connection between the high-voltage equipment and the power transmission line, and a linear chirp reference signal is injected into the measurement loop; wherein the interference isolation device comprises a multi-band adaptive inductance component, the multi-band adaptive inductance component is a nested adjustable inductance structure, the nested adjustable inductance structure comprises one main inductance and 3-6 distributed sub-inductances; all the sub-inductances adopt gradient permeability magnetic cores;

[0059] The partial discharge signal is continuously collected by using the high-voltage side pulse current method, the signal-to-noise ratio improvement rate and the interference attenuation rate are calculated based on the frequency spectrum characteristics and the characteristic parameters of the partial discharge signal, and then the interference isolation device parameters are adjusted according to the signal-to-noise ratio improvement rate and the interference attenuation rate, wherein the parameter adjustment response time is ≤1s;

[0060] The main interference frequency band is matched by the main inductance parameter, and the edge interference frequency band is matched by the air gap length; wherein the air gap length ranges from 0.1mm to 1mm;

[0061] The linear chirp reference signal is kept real-time frequency sweeping to track the interference frequency drift, and when the chirp signal monitors that the interference frequency drift exceeds 5%, the magnetic core displacement mechanism of the sub-inductance automatically adjusts the air gap length within ≤1s, so that the inductance impedance peak value is locked to the frequency after the drift.

[0062] Exemplarily, the magnetic core displacement mechanism adjusts the air gap length by a micro stepping motor (step distance ±0.001mm).

[0063] Exemplarily, the characteristic parameters include frequency spectrum, discharge amount, discharge times, discharge phase distribution, etc.

[0064] Exemplarily, the interference isolation device parameters include main inductance turns, sub-inductance turns, sub-inductance air gap length, etc.

[0065] Exemplarily, the interference isolation device can further comprise a cascade filter network formed by a plurality of multi-band adaptive inductance components in series and / or parallel.

[0066] In the preferred embodiment of the partial discharge detection anti-interference method, the main inductance and the sub-inductance in the selected multi-band adaptive inductance component are made of high permeability material, and the external insulating layer is made of high-voltage resistant insulating material.

[0067] In the preferred embodiment of the partial discharge detection anti-interference method, the inductance value of the nested adjustable inductance structure can be continuously adjusted.

[0068] In the partial discharge detection anti-interference method, the background signal and the partial discharge original signal before installation of the interference isolation device are obtained by using a partial discharge test platform, and the partial discharge signal after installation of the interference isolation device is obtained.

[0069] The partial discharge detection anti-interference method, utilizes a high-frequency current sensor to collect the background signal and the partial discharge original signal before installation of the interference isolation device, and the partial discharge signal after installation of the interference isolation device under a coverage frequency band of 10 kHz-100 MHz.

[0070] The partial discharge detection anti-interference method, the cross-correlation operation further includes:

[0071] A one-to-one correspondence between time and frequency is established through time-frequency mapping analysis, and the frequency resolution of the cross-correlation operation is ensured to be ≤1 kHz, and the identification error of the interference edge frequency is ensured to be ≤0.1 MHz.

[0072] The partial discharge detection anti-interference method, the interference isolation device further includes: a plurality of multi-frequency band adaptive inductors connected in parallel or in series to form a cascade filter network, wherein the main inductance frequency band difference of adjacent inductors is ≥1 MHz, the sub-inductance frequency band difference is ≥0.5 MHz, the frequency band distribution is based on 10 kHz-100 MHz full-frequency band interference distribution identified by the chirp signal; the impedance of the cascade network to the 50 Hz power frequency signal is ≤5 Ω.

[0073] In another embodiment, the present application discloses a partial discharge detection anti-interference system, which comprises:

[0074] The signal acquisition module, the signal processing module, the interference isolation device and the monitoring optimization module, wherein,

[0075] The signal acquisition module comprises a partial discharge test platform, a high-frequency current sensor and a chirp signal generator, wherein,

[0076] The partial discharge test platform comprises a partial discharge-free power supply, a current-limiting resistor, a capacitor voltage divider, an oscilloscope, a discharge cavity and a partial discharge-free voltage regulator, wherein the discharge cavity comprises any of the following electrodes: needle-plate, plate-plate and ball-plate electrodes;

[0077] The high-frequency current sensor is used to collect the background signal and the partial discharge original signal before installation of the interference isolation device, and the partial discharge signal after installation of the interference isolation device under a coverage frequency band of 10 kHz-100 MHz;

[0078] The chirp signal generator is used to generate a linear chirp reference signal with a sweep range of 10 kHz-100 MHz and an amplitude of 1 / 100 of the amplitude of the partial discharge original signal;

[0079] The signal processing module is connected to the signal acquisition module, and the signal processing module comprises a digital signal processor and a data analysis unit, wherein,

[0080] The digital signal processor is configured to perform fast Fourier transform on the partial discharge original signal to obtain a basic frequency band distribution, and synchronously extract a frequency spectrum feature of the partial discharge original signal, and perform cross-correlation operation on the linear chirp reference signal and the partial discharge original signal;

[0081] The data analysis unit is configured to calibrate the cross-correlation operation result in combination with the background signal, and determine a complete frequency band range of the external interference signal affecting the partial discharge detection based on the calibrated cross-correlation operation result; wherein the complete frequency band range includes a main interference frequency band and an edge interference frequency band.

[0082] The interference isolation device includes a multi-frequency band adaptive inductance component, wherein,

[0083] The multi-frequency band adaptive inductance component is a nested adjustable inductance structure, and the nested adjustable inductance structure includes one main inductance and 3-6 distributed sub-inductances; all the sub-inductances adopt gradient permeability magnetic cores.

[0084] The monitoring optimization module includes a partial discharge monitoring system and a parameter adjustment unit, wherein,

[0085] The partial discharge monitoring system is configured to continuously collect partial discharge signals by using a high-voltage side pulse current method, and calculate a signal-to-noise ratio improvement rate and an interference attenuation rate based on the frequency spectrum feature and a characteristic parameter of the partial discharge signal.

[0086] The parameter adjustment unit is configured to adjust the interference isolation device parameters according to the signal-to-noise ratio improvement rate and the interference attenuation rate, and keep the linear chirp reference signal real-time frequency sweeping to track the interference frequency drift, wherein,

[0087] Adjusting the interference isolation device parameters includes matching the main interference frequency band by the main inductance parameter, and matching the edge interference frequency band by the air gap length.

[0088] When the chirp signal monitors that the interference frequency drift exceeds 5%, the magnetic core displacement mechanism of the sub-inductance automatically adjusts the air gap length within ≤1s, so that the inductance impedance peak value is locked to the frequency after the drift.

[0089] The partial discharge-free power supply is, for example, a partial discharge-free transformer; a high-frequency current sensor (for example, a current induction coil, and for another example, a Rogowski coil) and a chirp signal generator,

[0090] For example, the multi-frequency band adaptive inductance component is connected in series at the connection between the high-voltage device and the power transmission line through a high-voltage sleeve or a detachable joint, and is externally wrapped with a high-voltage resistant insulation layer.

[0091] For example, the multi-frequency band adaptive inductance component further includes:

[0092] A metal shield is arranged around the multi-band adaptive inductor assembly or the combined magnetic ring.

[0093] Preferably, the ground resistance of the metal shield is ≤0.5Ω.

[0094] In another embodiment, the present application discloses a computer storage medium, which comprises computer instructions, when running on a computer, make the computer execute the method.

[0095] In another embodiment, the present application discloses an electronic device, which comprises:

[0096] The memory, the processor and the computer program stored in the memory and executable on the processor, wherein,

[0097] The processor executes the program to realize the method.

[0098] In another embodiment, the partial discharge detection anti-interference method comprises the following steps:

[0099] Step 1: Multi-source signal acquisition and chirp-frequency domain joint analysis The partial discharge signal in the air medium is obtained by using the partial discharge test platform, and the following signals are synchronously collected by the high-frequency current sensor: the partial discharge original signal; the background signal under the condition of no partial discharge.

[0100] The signal is analyzed by signal processing technology: the fast Fourier transform is performed on the partial discharge original signal to obtain the basic frequency band distribution, and the frequency spectrum characteristics of the partial discharge original signal are synchronously extracted; the linear chirp reference signal is generated according to the basic frequency band distribution. Illustratively, the chirp signal generator injects the linear chirp reference signal into the measurement loop; and the cross-correlation operation is performed on the chirp reference signal and the partial discharge original signal, and the complete frequency band of the interference signal is accurately positioned (illustratively, the complete frequency band includes the center frequency, the edge frequency and the bandwidth, and the error is ≤0.1 MHz).

[0101] Step 2: Multi-band adaptive inductor parameter design and interference isolation device installation

[0102] According to the interference frequency band obtained by the chirp-frequency domain joint analysis in step 1, the parameters of the multi-band adaptive inductor assembly are designed and installed as a component of the interference isolation device:

[0103] Parameter calculation: for the main interference frequency band, the formula The main inductance turns are calculated to ensure that the impedance of the frequency band is greater than or equal to 1 MΩ; for the edge interference frequency band, the sub-inductance turns are adjusted to make the impedance of each frequency band uniformly covered; and a sub-inductance air gap length adjustment space is reserved. The installation mode is as follows: at the connection between the high-voltage equipment and the power transmission line, the multi-frequency adaptive inductance assembly is installed in series through a high-voltage bushing or a detachable threaded joint; a copper metal shielding cover is arranged around to reduce spatial electromagnetic radiation interference.

[0104] Step 3: Continuously monitor three types of indicators through a partial discharge monitoring system (using a high-voltage side pulse current method):

[0105] After installing the interference isolation device, the partial discharge signal is continuously collected and the characteristic parameters thereof are obtained, such as discharge quantity error, discharge frequency fluctuation, and discharge phase shift; and the skilled person in the art knows that the interference suppression effect is focused on the following indicators: interference attenuation rate, signal-to-noise ratio improvement rate; and the interference frequency drift captured by the real-time sweep frequency of the chirp signal.

[0106] If the monitoring result does not reach the target, the micro stepping motor is driven through the parameter adjustment unit to dynamically optimize the inductance parameters: adjusting the sub-inductance air gap length (step distance ± 0.001 mm, response time ≤ 1 s); switching the sub-inductance turn combination to adapt to the new interference frequency band, forming a closed loop of "collection-frequency recognition-adjustment-re-monitoring".

[0107] In the preferred embodiment of the partial discharge detection anti-interference method, the selected multi-frequency adaptive inductance assembly is wrapped with a composite insulation layer, and a copper metal shielding cover is arranged around it, which effectively reduces electromagnetic radiation interference while ensuring the insulation performance of the assembly.

[0108] In the preferred embodiment of the partial discharge detection anti-interference method, the adjustable structure of the multi-frequency adaptive inductance assembly is used to change the sub-inductance air gap length (adjustment range 0.1-1 mm, step distance ± 0.001 mm) or switch the sub-inductance core position through a micro stepping motor, to realize continuous adjustment of the inductance value and dynamically adapt to the interference frequency drift.

[0109] In the preferred embodiment of the partial discharge detection anti-interference method, the partial discharge signal in the air medium is obtained by using a partial discharge test platform, which includes a partial discharge source, a current limiting resistor, a capacitor voltage divider, a discharge cavity, a discharge cavity, a current sensing coil with a bandwidth higher than 30 MHz, and a chirp signal generator; the discharge cavity includes needle-plate electrodes, plate-plate electrodes, or ball-plate electrodes, which can simulate partial discharge under different working conditions by adjusting the electrode distance (2-10 mm); the chirp signal generator is used to generate a linear chirp reference signal with a sweep frequency range of 10 kHz-100 MHz and an amplitude of 1 / 100 of the original partial discharge signal amplitude, which is synchronously injected into the measurement loop through the current sensing coil.

[0110] The preferred embodiment of the partial discharge detection anti-interference method uses a high-frequency current sensor (frequency band 10 kHz-100 MHz, sampling rate ≥1 GHz, collection accuracy ≤0.1 mV) to synchronously collect three types of signals: partial discharge original signal, linear chirp reference signal, and no partial discharge background signal; the high-frequency current sensor needs to be connected to the measurement circuit through a high-voltage sleeve or a shielded cable to provide high-quality data for subsequent frequency domain analysis.

[0111] In the preferred embodiment of the partial discharge detection anti-interference method, the characteristic parameters include discharge quantity, discharge frequency, and discharge phase distribution, and the specific comparison requirements are as follows:

[0112] Discharge quantity: calculated by high-voltage side pulse current method, the measurement error of discharge quantity before and after installation of the interference isolation device should be ≤5%, and the single discharge quantity fluctuation amplitude should be ≤10%;

[0113] Discharge frequency: the number of effective discharges per unit time (1 minute) is counted, and the discharge frequency fluctuation after installation should be ≤10%, and there should be no "false discharge frequency" caused by interference (the proportion of false frequency should be reduced to below 5%);

[0114] Discharge phase distribution: analyze the phase distribution of the discharge signal in the 50 Hz power frequency cycle, and after installation, it should meet the typical characteristics of the partial discharge of the high-voltage equipment.

[0115] In the preferred embodiment of the partial discharge detection anti-interference method, the interference isolation device parameters include the main / secondary inductance turns of the multi-band adaptive inductor, the secondary inductance air gap length, and the parallel composite filter network, and the specific adjustment method is as follows: main / secondary inductance turns adjustment: for the main interference frequency band of the chirp signal identification, the main inductance turns are calculated by the formula ; for the edge interference frequency band, the secondary inductance turns are adjusted to ensure that the impedance of each frequency band is ≥1 MΩ; secondary inductance air gap length adjustment: the micro stepping motor is driven by the parameter adjustment unit to change the secondary inductance air gap length to adapt to the interference frequency drift of the chirp signal tracking; composite filter network optimization: multiple multi-band adaptive inductors are connected in parallel or series to form a cascaded network, the main inductance frequency band difference of adjacent inductors is ≥1 MHz, and the filter frequency band is expanded to the full range of 10 kHz-100 MHz;

[0116] A partial discharge detection anti-interference system for implementing the method includes a signal collection module, a signal processing module, an interference isolation device, and a monitoring optimization module, which cooperatively realize wide-band interference identification and dynamic suppression, and the specific structure is as follows:

[0117] Signal collection module

[0118] Partial discharge test platform: including no partial discharge transformer (output voltage 110kV-220kV), current limiting resistor, no partial discharge voltage regulator (adjustment range 0-120kV), capacitor voltage divider (division ratio 1000:1), oscilloscope (bandwidth ≥200MHz, sampling rate ≥1GHz), discharge cavity (for example, the discharge cavity includes any of the following electrodes: needle-plate electrode, plate-plate electrode, sphere-plate electrode);

[0119] Chirp signal generator (sweeping range 10kHz-100MHz);

[0120] High-frequency current sensor (for example, a current induction coil is used as a high-frequency current sensor; further, the current induction coil uses a Rogowski coil): frequency band covers 10kHz-100MHz, sampling rate ≥1GHz, collection accuracy ≤0.1mV, connected with a signal processing module through a shielded cable, used for synchronously collecting partial discharge original signals and background signals, and the collection timing is synchronized with the chirp signal generator;

[0121] Signal processing module

[0122] Digital signal processor, configured to: perform fast Fourier transform on the partial discharge original signals to obtain a basic frequency band distribution, synchronously extract spectral features of the partial discharge original signals, and perform cross-correlation operation on the partial discharge original signals and a linear chirp reference signal;

[0123] Data analysis unit, used for calibrating a result of the cross-correlation operation in combination with the background signals, and determining a complete frequency band range of an external interference signal affecting partial discharge detection based on the calibrated result of the cross-correlation operation; wherein the complete frequency band range includes a main interference frequency band and an edge interference frequency band (for example, the complete frequency band range more specifically includes a center frequency, an edge frequency and a bandwidth, etc.);

[0124] Interference isolation device

[0125] Multi-band adaptive inductor assembly: a nested adjustable inductor structure, including 1 main inductor and 3-6 distributed sub-inductors, connected in series through a high-voltage sleeve or a detachable threaded joint at a connection between a high-voltage device and a power transmission line;

[0126] Metallic shield: made of copper material, arranged around the multi-band adaptive inductor assembly, with a grounding resistance ≤0.5Ω, used for shielding spatial electromagnetic radiation interference.

[0127] Monitoring optimization module

[0128] Partial discharge monitoring system: adopts a high-voltage side pulse current method to collect partial discharge signals, displays discharge quantity, discharge times, discharge phase distribution and spectral features in real time, calculates signal-to-noise ratio improvement rate and interference attenuation rate, and transmits evaluation results to a parameter adjustment unit;

[0129] Parameter adjustment unit: configured to receive interference frequency band drift data of signal processing module and effect evaluation result of monitoring system, drive magnetic core displacement of sub-inductor through micro stepping motor (step distance ± 0.001 mm), adjust air gap length (remark: other adjustment parameter means include: switching sub-inductor turns), realize dynamic optimization of inductance parameter, adjust response time ≤1s, and ensure stable interference suppression effect.

[0130] In another embodiment, a partial discharge measurement anti-interference method comprises the following steps,

[0131] S1: partial discharge test platform and multi-source signal acquisition Figure 2 The partial discharge test platform shown in the figure carries out tests in air medium:

[0132] Discharge cavity: adjust electrode distance (2-10 mm) of needle-plate electrode, plate-plate electrode and sphere-plate electrode to simulate partial discharge under different working conditions; signal acquisition: synchronously acquire three types of signals through high-frequency current sensor (frequency band 10 kHz-100 MHz, sampling rate ≥1 GHz): partial discharge original signal; linear chirp reference signal injected by chirp signal generator (sweeping range 10 kHz-100 MHz, amplitude 1 / 100 of original signal amplitude); background signal under no partial discharge state.

[0133] S2: chirp-frequency domain joint signal analysis Use digital signal processing technology to analyze the three types of signals: frequency domain analysis: preliminarily extract basic frequency band distribution of the signal through fast Fourier transform; interference signal frequency identification: perform cross-correlation operation on the chirp reference signal and the original signal to accurately locate the complete frequency band of the interference signal.

[0134] S3: multi-band adaptive inductance parameter calculation According to the interference frequency band determined in S2 and the inductance impedance characteristic formula , calculate multi-band adaptive inductance component parameters: main inductor: ensure that the impedance of the main interference frequency band is ≥1 MΩ; sub-inductor: ensure that the impedance of each frequency band is uniformly covered.

[0135] S4: multi-band inductance component installation Install the multi-band adaptive inductance component (nested structure of main inductor+distributed sub-inductor) at the connection between the high-voltage device and the power transmission line through high-voltage bushing or detachable threaded joint. The installation needs to meet the following requirements: insulation protection: the component is wrapped with an insulation layer.

[0136] S5: metal shielding cover setting around the multi-band adaptive inductance component Install a copper metal shielding cover, and the shielding cover is reliably grounded (grounding resistance ≤0.5 Ω) to reduce the interference of space electromagnetic radiation on inductance parameters and signal acquisition.

[0137] S6: Real-time monitoring of partial discharge signals Real-time monitoring of partial discharge signals of high-voltage equipment using a partial discharge monitoring system by using a high-voltage side pulse current method, including the following monitoring contents: discharge quantity, discharge times, discharge phase distribution characteristic parameters; signal spectrum characteristics (updated in real time by FFT).

[0138] S7: Comparison of signal characteristic parameters Comparison of signal characteristic parameters before and after installation of the multi-band adaptive inductor assembly: discharge quantity: calculate the discharge quantity measurement error before and after installation; discharge times: count the effective discharge times in a unit time (1 minute), and calculate the fluctuation amplitude; discharge phase distribution: analyze the phase distribution of the discharge signal in the 50Hz power frequency cycle, and judge whether it meets the discharge characteristics of the device itself.

[0139] S8: Interference suppression effect evaluation Establish an interference suppression effect evaluation model to calculate two core indicators: signal-to-noise ratio (SNR) improvement rate according to the following formula (1):

[0140] ,

[0141] Wherein,

[0142] a represents the SNR improvement rate,

[0143] b represents the SNR of the characteristic parameters of the partial discharge signal after installation of the interference isolation device,

[0144] c represents the spectrum characteristics of the original partial discharge signal before installation of the interference isolation device;

[0145] The interference signal attenuation rate (also known as signal suppression rate) is according to the following formula (2):

[0146] ,

[0147] Wherein,

[0148] d represents the interference attenuation rate,

[0149] e represents the interference amplitude before installation of the interference isolation device,

[0150] f represents the interference amplitude after installation of the interference isolation device.

[0151] S9: Inductive parameter dynamic optimization If it is found that there is still an interference signal affecting the measurement result, the inductive parameter is dynamically optimized by the parameter adjustment unit according to the frequency drift, intensity change and other characteristics of the interference signal: air gap adjustment: drive a micro stepping motor (step distance ± 0.001 mm) to change the air gap length of the sub-inductive magnetic core (adjustment range 0.1-1 mm) to adapt to the interference frequency drift; composite filter network: parallel or series connection of multiple multi-frequency adaptive inductive components to form a cascade network (the difference between adjacent inductive main inductance frequency bands is ≥1MHz) to expand the filter frequency band to the full range of 10kHz-100MHz; auxiliary measures: install a capacitor coupler (capacitance 100-500pF) on the high-voltage equipment side to extract the target frequency component, or set a notch filter in the measurement loop to suppress specific frequency interference, and use differential measurement technology to eliminate common-mode interference.

[0152] Referring to Figure 2 In another embodiment, the partial discharge test platform comprises: a partial discharge-free transformer 1 (output voltage 110kV-220kV), a current-limiting resistor 2, a capacitive voltage divider 3 (division ratio 1000:1), an oscilloscope 4 (bandwidth ≥200MHz, sampling rate ≥1GHz), a discharge cavity 5, a Rogowski coil 6 and a partial discharge-free voltage regulator 7, and a chirp signal generator 8 (sweeping range 10kHz-100MHz, amplitude adjustment range 0.01-1mV, amplitude is 1 / 100 of the original partial discharge signal).

[0153] For example, the Rogowski coil 6: frequency band covers 10kHz-100MHz, sampling rate ≥1GHz, collection accuracy ≤0.1mV, used for collecting the background signal, the original partial discharge signal and the partial discharge signal.

[0154] Further, the application uses a current induction coil (HFCT) to synchronously collect the original partial discharge signal, the linear chirp reference signal and the partial discharge-free background signal in the air medium in the frequency band range of 10kHz-100MHz; through the joint method of "fast Fourier transform (FFT) frequency domain analysis + chirp-original signal cross-correlation operation", the complete frequency band (including the center frequency, the edge frequency and the bandwidth) of the interference signal is accurately identified, the defects that the traditional single FFT can only identify the fixed frequency and cannot capture the edge frequency band are solved, the "wide frequency band targeted basis" is provided for the subsequent design of the parameter of the interference isolation device, the air partial discharge interference conducted on the overhead line is filtered out in a targeted manner to avoid its coupling to the partial discharge measurement loop of the high-voltage equipment. Design and installation of multi-frequency adaptive inductive components: according to the interference frequency band obtained by chirp frequency identification, the inductive impedance formula The main / sub-inductance parameters are calculated; the components are connected in series through high-voltage bushings or detachable threaded joints at the connection between the high-voltage equipment and the power transmission line, wrapped with an external insulation layer and provided with a metal shielding cover (ground resistance ≤0.5 Ω), which forms high resistance (impedance of each frequency band ≥1 MΩ) to wide-band interference and shields space electromagnetic radiation, ensuring long-term stable operation of the components. After the installation of the multi-frequency adaptive inductance components, the discharge quantity, discharge frequency, and discharge phase distribution characteristic parameters are continuously and real-timely monitored through the partial discharge monitoring system, and the interference suppression effect is evaluated in combination with the signal-to-noise ratio improvement rate and the interference attenuation rate; the parameter adjustment unit can drive the micro stepping motor to adjust the sub-inductance air gap length (step distance ±0.001 mm) or switch the sub-inductance number of turns based on the real-time sweep frequency data of the chirp signal, complete parameter adaptation within ≤1 s, and ensure the stability of the interference suppression effect. In addition, the filtering range can be expanded to the full frequency band of 10 kHz-100 MHz by forming a cascade network through “parallel / series connection of multiple multi-frequency adaptive inductances” (the main frequency band difference of adjacent inductances is ≥1 MHz), or the adaptability of the system to complex interference can be further enhanced by cooperating with a capacitance coupler (extracting target frequency components) and a differential measurement technology in the measurement loop, thereby significantly improving the accuracy and reliability of the partial discharge detection of high-voltage equipment.

[0155] The application substantially discloses a high-frequency signal control model of “chirp frequency recognition-multi-frequency inductance cooperative suppression”, wherein the impedance of the inductance to the high-frequency signal satisfies the formula Z L =2π×f×L, wherein Z L is the inductance impedance, f is the signal frequency, and L is the inductance value. When the inductance impedance is much larger than the equivalent impedance Z0 of the circuit, the corresponding frequency signal can be effectively blocked. Meanwhile, the chirp signal can track the interference frequency drift in real time, and the inductance parameters can be dynamically adjusted when the drift meets certain conditions, thereby solving the defect of the traditional single inductance “fixed parameters cannot adapt to wide-band interference”.

[0156] In another embodiment, a multi-frequency adaptive inductance suppression experiment based on a 5 MHz partial discharge signal is carried out for the air medium partial discharge detection scene of a 110 kV high-voltage equipment.

[0157] By linear chirp signal (sweep range 10kHz-100MHz, amplitude is 1 / 100 of the original signal) and partial discharge original signal correlation operation, combined with fast Fourier transform (FFT) frequency domain analysis, the complete frequency band of the interference signal is accurately located as 3-7MHz; further through "chirp signal time-frequency mapping" (time-frequency one-to-one correspondence), it is found that the interference signal amplitude of 5MHz frequency band is the largest (11mV), and covers the adjacent frequency band of the partial discharge effective signal (3MHz, amplitude 2mV), which becomes the core conflict frequency band of interference and effective signal. In order to target inhibit the 5MHz core interference frequency band, combined with the frequency band characteristics of chirp frequency recognition, the main inductance value L=15mH of the multi-frequency adaptive inductance component is preliminarily selected for experimental verification, and the sub-inductance is set as 20mH (3MHz) and 10mH (7MHz), that is, two sub-inductances are used to cover the edge frequency band. In this embodiment, the main inductance and all sub-inductances are in series, which ensures that the dual effects of "core frequency band suppression" and "wide frequency band coverage" are verified at the same time.

[0158] The results show that: without installing multi-frequency inductance, the amplitude of 5MHz interference signal is 11mV, the amplitude deviation of 3MHz effective signal after being interfered and superimposed is ±4mV, and the amplitude of 7MHz edge interference is 7mV; after installing multi-frequency adaptive inductance (main inductance 15mH+sub-inductance 20mH / 10mH), the interference amplitude of 5MHz is suppressed to 3mV, the amplitude deviation of 3MHz effective signal is reduced to ±0.6mV, and the interference amplitude of 7MHz is suppressed to 0.7mV; the signal waveform comparison chart of the two states is shown in Figure 3 The signal suppression rate of the core frequency band (5MHz) is calculated according to the above formula (2), and the result is 72.7%. This result shows that the multi-frequency adaptive inductance component of the present application not only has a significant suppression effect on the 5MHz core interference frequency band, but also can cover the 3MHz and 7MHz edge frequency bands through the sub-inductance, avoiding the problem of "suppressing the core frequency band but missing the edge frequency band" of the traditional single inductance, which meets the current file "10kHz-100MHz wide frequency band anti-interference" demand.

[0159] Combined with experimental data and inductance impedance formula, the correlation model of "chirp frequency recognition frequency band-multi-frequency inductance parameter-suppression rate" is constructed: the interference frequency f=5x10 6 Hz of 5MHz is known, the main inductance value L=15mH=15x10 -3 H is substituted into the formula Z L =2πx f x L, and the impedance of the main inductance at 5MHz is obtained:

[0160] Z L =2πx5x10 6 x15x10 -3 ≈4.71x10 5 Ω,

[0161] Assuming the experimental setting Z0=1MΩ,

[0162] At the same time, the impedance of the sub-inductors at 3MHz and 7MHz is respectively:

[0163] Z L2 =2π×3×10 6 ×20×10 -3 ≈3.77×10 5 Ω,

[0164] Z L3 =2π×7×10 6 ×10×10 -3 ≈4.40×10 5 Ω,

[0165] It should be noted that the impedance of the main inductor and all sub-inductors is about half of Z0, which does not hinder the full-band suppression of the present embodiment through "high impedance of main inductor + coordination of sub-inductors", which will be detailed in the specific calculation below.

[0166] In addition, in the present embodiment, the main inductor and the two sub-inductors are added, i.e., the main inductor and all sub-inductors are in series, and there are 15+20+10=45mH, i.e., the equivalent inductance L eq =45mH, under this embodiment, the relationship model of "suppression rate and inductance value, signal frequency, and chirp recognition frequency deviation" is derived as follows, and the suppression rate d has the following formula (3):

[0167] ,

[0168] Where k is the chirp recognition frequency deviation coefficient, and for every 1MHz increase in recognition frequency deviation, an additional kMΩ impedance needs to be compensated to offset the deviation; in the current experiment, k=10 2 MΩ / MHz; Δf is the frequency deviation of the chirp recognition frequency, and in the current experiment, Δf=0.05MHz≤0.1MHz,

[0169] Substitute the experimental data Z0=1MΩ, f=5×10 6 Hz, L eq =45mH, and Δf=0.05MHz, and the suppression rate is calculated to be about 84.4%, which deviates from the actual suppression rate (about 72.7%) by about 12%. After analysis, the deviation is caused by the influence of the line-to-ground capacitance and stray capacitance on the inductance, and the error of 10±2% is within the allowable error range in engineering, and the model is effective. The model can be real-time corrected by Δf of the chirp signal output, and provides dynamic guidance for multi-band inductance parameter selection under different frequencies and different suppression requirements.

[0170] Further, regarding the influence on the power frequency signal: the power frequency signal frequency in our country is 50Hz, and the equivalent inductance L of the multi-band adaptive inductor is 45mH, the impedance Z of the power frequency signal is calculated as follows: eq L-power :

[0171] Z L-power =2π×50×45×10 -3 ≈14.14Ω,

[0172] Since Z L-power <<Z0=1MΩ, it means that the impedance of the power frequency signal current can be ignored, and it fully meets the constraint of "not affecting the normal operation of high-voltage equipment".

[0173] Although the embodiments of the present application are described above in combination with the drawings, the present application is not limited to the above specific embodiments and application fields, and the above specific embodiments are only illustrative and guiding, but not limiting. Those skilled in the art can make many forms under the guidance of the present application and without departing from the scope protected by the claims of the present application, which all belong to the protection of the present application.​

Claims

1. A partial discharge detection anti-interference method, characterized in that, The method comprises the following steps: obtaining a background signal in a no-partial-discharge state before installation of an interference isolation device, and a partial discharge original signal in an air medium; performing fast Fourier transform on the partial discharge original signal to obtain a basic frequency band distribution, and synchronously extracting a frequency spectrum feature of the partial discharge original signal; generating a linear chirp reference signal according to the basic frequency band distribution, and performing cross-correlation operation on the linear chirp reference signal and the partial discharge original signal; calibrating a result of the cross-correlation operation in combination with the background signal, and determining a complete frequency band range of an external interference signal affecting partial discharge detection based on a calibrated result of the cross-correlation operation, wherein the complete frequency band range comprises a main interference frequency band and an edge interference frequency band; installing the interference isolation device in a series mode at a connection between a high-voltage device and a power transmission line, and injecting the linear chirp reference signal into a measurement loop; wherein the interference isolation device comprises a multi-frequency-band adaptive inductor assembly, the multi-frequency-band adaptive inductor assembly is a nested adjustable inductor structure, and the nested adjustable inductor structure comprises a main inductor and distributed sub-inductors; continuously collecting a partial discharge signal by using a high-voltage side pulse current method, calculating a signal-to-noise ratio improvement rate and an interference attenuation rate based on the frequency spectrum feature and a characteristic parameter of the partial discharge signal, and then adjusting a parameter of the interference isolation device according to the signal-to-noise ratio improvement rate and the interference attenuation rate; matching the main interference frequency band by a main inductor parameter, and matching the edge interference frequency band by an air gap length; keeping the linear chirp reference signal real-time frequency sweeping to track a drift of an interference frequency, and automatically adjusting the air gap length by a magnetic core displacement mechanism of a sub-inductor when the chirp signal monitors that the drift of the interference frequency exceeds 5%, so that an inductive impedance peak value is locked to a frequency after the drift.

2. The partial discharge detection anti-interference method according to claim 1, characterized in that, The main inductor and the sub-inductors in the multi-frequency-band adaptive inductor assembly are made of high magnetic permeability materials, and an external wrapping insulation layer is made of high-voltage resistant insulation materials; the main inductor is 1, and the sub-inductors are 3-6; all the sub-inductors adopt gradient magnetic permeability magnetic cores.

3. The partial discharge detection anti-interference method according to claim 1, wherein, A response time of the parameter of the interference isolation device is less than or equal to 1s; the air gap length ranges from 0.1mm to 1mm; and an inductance value of the nested adjustable inductor structure can be continuously adjusted.

4. The partial discharge detection anti-interference method according to claim 1, wherein, The background signal and the partial discharge original signal before installation of the interference isolation device are obtained by using a partial discharge test platform, and the partial discharge signal after installation of the interference isolation device is obtained.

5. The partial discharge detection anti-interference method according to claim 4, characterized in that, The background signal and the partial discharge original signal before installation of the interference isolation device, and the partial discharge signal after installation of the interference isolation device are collected by using a high-frequency current sensor under a coverage frequency band of 10kHz-100MHz.

6. The partial discharge detection anti-interference method according to claim 1, wherein, The cross-correlation operation further comprises: establishing a one-to-one correspondence between time and frequency by time-frequency mapping analysis, and ensuring that a frequency resolution of the cross-correlation operation is less than or equal to 1kHz, and ensuring that an error of interference edge frequency identification is less than or equal to 0.1MHz.

7. The partial discharge detection anti-interference method according to claim 1, wherein, The interference isolation device further comprises: a plurality of multi-band adaptive inductors connected in parallel and / or in series to form a cascade filter network, wherein the main inductance frequency band difference of adjacent inductors is greater than or equal to 1 MHz, and the sub-inductance frequency band difference is greater than or equal to 0.5 MHz, and the frequency band distribution is based on the 10 kHz-100 MHz full-band interference distribution identified by the chirp signal; the impedance of the cascade network to the 50 Hz power frequency signal is less than or equal to 5 Ω.

8. A partial discharge detection anti-interference system, characterized in that, It comprises: a signal acquisition module, a signal processing module, an interference isolation device, and a monitoring optimization module, wherein the signal acquisition module comprises a partial discharge test platform, a high-frequency current sensor, and a chirp signal generator, wherein the partial discharge test platform comprises a partial discharge-free power supply, a current-limiting resistor, a capacitor voltage divider, an oscilloscope, a discharge cavity, and a partial discharge-free voltage regulator, wherein the discharge cavity comprises any of the following electrodes: needle-plate, plate-plate, and sphere-plate electrodes; the high-frequency current sensor is used to acquire background signals and original partial discharge signals before the installation of the interference isolation device, and partial discharge signals after the installation of the interference isolation device, covering a frequency band of 10 kHz-100 MHz; the chirp signal generator is used to generate a linear chirp reference signal with a sweep range of 10 kHz-100 MHz and an amplitude of 1 / 100 of the amplitude of the original partial discharge signal; the signal processing module is connected to the signal acquisition module, and the signal processing module comprises a digital signal processor and a data analysis unit, wherein the digital signal processor is configured to perform fast Fourier transform on the original partial discharge signal to obtain the basic frequency band distribution, synchronously extract the spectral features of the original partial discharge signal, and perform cross-correlation operation on the linear chirp reference signal and the original partial discharge signal; the data analysis unit is used to calibrate the cross-correlation operation result in combination with the background signal, and determine the complete frequency band range of the external interference signal affecting the partial discharge detection based on the calibrated cross-correlation operation result; wherein the complete frequency band range includes the main interference frequency band and the edge interference frequency band; the interference isolation device comprises a multi-band adaptive inductor assembly, wherein the multi-band adaptive inductor assembly is a nested adjustable inductor structure, which comprises one main inductor and 3-6 distributed sub-inductors; all sub-inductors use gradient permeability magnetic cores; the monitoring optimization module comprises a partial discharge monitoring system and a parameter adjustment unit, wherein the partial discharge monitoring system is used to continuously acquire partial discharge signals using high-voltage side pulse current method, and calculate signal-to-noise ratio improvement rate and interference attenuation rate based on the spectral features and characteristic parameters of the partial discharge signals; the parameter adjustment unit is configured to adjust the interference isolation device parameters according to the signal-to-noise ratio improvement rate and the interference attenuation rate, and keep the linear chirp reference signal real-time sweeping to track the interference frequency drift, wherein adjusting the interference isolation device parameters includes matching the main interference frequency band through the main inductor parameters, and matching the edge interference frequency band through the air gap length; when the chirp signal monitoring detects that the interference frequency drift exceeds 5%, the magnetic core displacement mechanism of the sub-inductor automatically adjusts the air gap length within ≤1 s, so that the inductance impedance peak value is locked to the frequency after the drift.

9. A computer storage medium, characterized in that The storage medium comprises computer instructions which, when run on a computer, cause the computer to perform the method of any one of claims 1-7.

10. An electronic device, comprising: The electronic device comprises: a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1-7 when executing the program.

Images