Method and device for atomic detection of partial discharge signals

Abstract

A method and device for atomic detection of partial discharge signals belongs to the technical field of detecting partial discharge signals. It generates and modulates atomic light signals; performs signal interaction and coupling; performs photoelectric detection and signal extraction, and analyzes and identifies partial discharge characteristics. Thus, by constructing a closed-loop frequency stabilization and digital pre-distortion modulation system, the high stability and repeatability of the atomic light signal are ensured. The coplanar waveguide structure realizes efficient coupling of the electronic light signal and the electrical signal to be measured, and the combination of dual-channel differential detection and feature extraction algorithm effectively identifies partial discharge events. The method has the advantages of high sensitivity, strong anti-interference ability and non-contact detection, and is suitable for practical application scenarios such as high-voltage equipment status monitoring and power system online detection. The present invention utilizes the interaction between the atomic light signal and the signal to be measured, and detects the changes in the light signal caused by the interaction to achieve high-sensitivity and high anti-interference detection of partial discharge signals.

Description

Technical Field

[0001] The invention belongs to the technical field of detecting partial discharge signals, and in particular relates to a method and device for atomic detection of partial discharge signals. Background Art

[0002] Currently, partial discharge detection mostly relies on capacitive coupling, as demonstrated in patent publication number "CN110045241B." These methods are susceptible to on-site electromagnetic interference, resulting in reduced detection sensitivity and even misjudgment. To overcome these issues, some research has attempted to introduce optical detection methods, but their response to partial discharge signals is still limited by the coupling method between the optical system and the object being measured. Existing technologies lack a detection mechanism that utilizes the physical interaction between atomic light signals and the measured signal to reveal partial discharge characteristics. Summary of the Invention

[0003] To address the shortcomings of the prior art, the present invention proposes a method and device for atomic detection of partial discharge signals. By utilizing the interaction between atomic optical signals and the signal to be measured and detecting the changes in the optical signal caused by this interaction, high-sensitivity and high-anti-interference detection of partial discharge signals can be achieved.

[0004] The present invention utilizes the following technical solutions.

[0005] A method for atomic detection of partial discharge signals, comprising:

[0006] Step 1: Generate and modulate atomic light signals;

[0007] Step 2: Perform signal interaction and coupling;

[0008] Step 3: Photoelectric detection and signal extraction;

[0009] Step 4: Partial discharge feature analysis and identification.

[0010] Furthermore, in step 1, a narrow linewidth laser is used to excite a specific atomic medium to generate an atomic resonance light signal; an external electro-optical modulator is set in the optical path of the atomic resonance light signal, and the atomic resonance light signal is modulated by the external electro-optical modulator. The atomic light signal formed after the modulation is used as a probe signal for physically interacting with the electrical signal to be measured.

[0011] Furthermore, in step 2, the modulated atomic light signal and the electrical signal to be measured are coupled in a set space, that is, the atomic light signal and the electrical signal to be measured realize physical interaction at the electromagnetic field level through the set space.

[0012] Furthermore, in step 2, an open resonant cavity structure is used in the set space to enhance the interaction efficiency between the atomic optical signal and the electrical signal to be measured, and an electromagnetic shielding structure is introduced in the set space.

[0013] Furthermore, in step 3, a balanced photodetector is used to receive the atomic light signal after interaction, and the original electrical signal to be measured is simultaneously introduced as a reference channel to form a differential detection structure; the photodetector converts the atomic light signal into an electrical signal, and digitally samples it through an analog-to-digital converter and transmits the digitally sampled data to the FPGA controller. The FPGA controller uses phase-locked amplification or digital orthogonal demodulation method to demodulate the digitally sampled data and extract its amplitude, phase or frequency offset.

[0014] Furthermore, in step 3, the balanced photodetector is composed of two symmetrical PIN photodiodes, and the two symmetrical PIN photodiodes form two optical paths; the output voltage signal of the balanced photodetector is It is proportional to the difference in light intensity between the two light paths and satisfies the following expression:

[0015]

[0016] in To balance the responsivity of the photodetector, and are the incident light intensities of the atomic light signal on the two optical paths respectively.

[0017] Furthermore, in step 4, the FPGA controller synchronously processes the sampled data of the received electronic light signal and the sampled data of the electrical signal to be measured, and extracts the following partial discharge characteristics as key features:

[0018] Transient amplitude change of electronic light signal , electronic optical signal phase shift The mutual correlation coefficient between the electronic light signal and the measured electrical signal .

[0019] Furthermore, in step 4, two channels of the high-speed analog-to-digital converter perform parallel data sampling on the electronic optical signal and the electrical signal to be measured using a high-precision clock synchronization unit;

[0020] Based on the variance analysis method, the transient amplitude change of the electronic light signal in the set time period is extracted , specifically including:

[0021] (1) Perform baseline calibration: Obtain the optical signal baseline during a set period without partial discharge. , The calculation formula is:

[0022] 𝐼

[0023] in The number of digitally sampled data of the electronic optical signal during the set period without partial discharge, The first digital sampling of the electronic light signal during the set period without partial discharge The amplitude value of each data;

[0024] (2) Transient detection: using variance analysis, first obtain the variance of the amplitude value of the digitally sampled data of the electronic light signal during the set period without partial discharge. , when the first digital sampling of the electronic light signal during the set period The amplitude value of the data exist When the It is determined to be a transient amplitude value and is defined as ;𝜎

[0025] (3) Transient amplitude change The calculation formula is:

[0026]

[0027] in To seek The maximum value of

[0028] The electronic optical signal formed after modulation is converted into in-phase and quadrature components by digital orthogonal demodulation method, and the phase offset of the electronic optical signal is calculated by four-quadrant inverse tangent algorithm. , which specifically include:

[0029] (1) Perform orthogonal demodulation: The electronic light signal formed after modulation is Digitally sampled data Perform quadrature demodulation, where is the frequency of the electronic light signal, The electronic light signal at time The phase, is the amplitude of the electronic light signal, and the moment is obtained after orthogonal demodulation The in-phase component and orthogonal components ;

[0030] (2) Phase extraction: Use the four-quadrant inverse tangent algorithm to calculate the time The instantaneous phase ;

[0031] (3) Calculate the phase offset of the electronic light signal ,in is the average of the instantaneous phases of all sampling moments of the electronic light signal during the set period, is the average of the instantaneous phases of the electronic optical signal at all sampling moments during a set period without partial discharge;

[0032] Construct the cross-correlation function of the electronic light signal to obtain the cross-correlation coefficient between the electronic light signal and the electrical signal to be measured , which specifically include:

[0033] (1) Constructing the cross-correlation function of the electron-light signal ,in The first digital sampling of the electronic light signal during the set period data, The first digital sampling of the electrical signal to be measured during the set period data, is the average number of digitally sampled data of the electronic light signal during a set period of time, The average number of digitally sampled data of the electrical signal to be measured during a set period of time;

[0034] (2) The mutual correlation coefficient between the electronic light signal and the measured electrical signal The calculation formula is ,in To seek The maximum value of .

[0035] Furthermore, in step 4, the transient amplitude change of the electronic light signal is , electronic optical signal phase shift The mutual correlation coefficient between the electronic light signal and the measured electrical signal After normalization, the data is input into the multi-layer perceptron classifier; the multi-layer perceptron classifier adopts a three-layer structure: 3 nodes in the input layer, 10 nodes in the hidden layer, and 1 node in the output layer. The activation function is ReLU, and the output layer uses the Sigmoid function to generate the partial discharge probability value. , if the partial discharge probability value Higher than the set threshold , it is determined that partial discharge exists, otherwise it is determined that no partial discharge exists.

[0036] A device for atomically detecting partial discharge signals, comprising:

[0037] The photodetector, the analog-to-digital converter and the FPGA controller are sequentially connected, and the analog-to-digital converter is also connected to the analog-to-digital converter;

[0038] The device for atomically detecting partial discharge signals further comprises:

[0039] A generation module, which is used to generate and modulate atomic light signals;

[0040] A coupling module, which is used for signal interaction and coupling;

[0041] Extraction module, which is used for photoelectric detection and signal extraction;

[0042] The identification module is used for partial discharge feature analysis and identification.

[0043] The beneficial effects of the present invention are that, compared with the prior art, the technical effects of the present invention include:

[0044] The present invention generates and modulates atomic optical signals; performs signal interaction and coupling; performs photoelectric detection and signal extraction; and analyzes and identifies partial discharge characteristics. This ensures high stability and repeatability of the atomic optical signals by constructing a closed-loop frequency stabilization and digital predistortion modulation system. A coplanar waveguide structure achieves efficient coupling of the electronic optical signal with the electrical signal to be measured. Combined with a dual-channel differential detection and feature extraction algorithm, partial discharge events can be effectively identified. This method offers advantages such as high sensitivity, strong interference resistance, and non-contact detection, making it suitable for practical applications such as high-voltage equipment status monitoring and online power system testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flow chart of the method for atomic detection of partial discharge signals of the present invention;

[0046] Figure 2 It is a module structure diagram of the device for atomic detection of partial discharge signals in the present invention. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the present invention more clear, the following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely express the technical solutions of the present invention. The embodiments expressed in this application are only some embodiments of the present invention, not all embodiments. Based on the spirit of the present invention, other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0048] like Figure 1 As shown, the method for detecting partial discharge signals by atoms according to the present invention includes:

[0049] Step 1: Generate and modulate atomic light signals;

[0050] The purpose of step 1 is to generate an atomic light signal of a specific frequency.

[0051] In a preferred but non-limiting embodiment of the present invention, in step 1, a narrow linewidth laser is used to excite a specific atomic medium (such as rubidium atomic vapor) to generate an atomic resonance light signal with stable frequency and polarization characteristics; when passing through the atomic medium, the atomic resonance light signal undergoes an electromagnetic induced transparency (EIT) effect or a coherent population transfer (CPT) effect, forming an optical probe with high stability and tunable characteristics. An external electro-optical modulator is set in the optical path of the atomic resonance light signal, and the atomic resonance light signal is modulated by the external electro-optical modulator so that it has specific frequency modulation or phase encoding characteristics to enhance the signal-to-noise ratio and anti-interference ability in subsequent detection. The atomic light signal formed after the modulation is used as a probe signal for physical interaction with the electrical signal to be measured. This process ensures that the atomic light signal has a high sensitivity response to the electromagnetic disturbance caused by local discharge in the subsequent interaction.

[0052] In an embodiment of the present invention, a narrow-linewidth laser (linewidth <10 kHz) with a central wavelength of 780 nm is used to excite a rubidium atomic vapor cell. The laser frequency is precisely locked to the resonant frequency of the rubidium atomic D2 hyperfine transition (85Rb F=2→F'=3) to stimulate the electromagnetically induced transparency (EIT) effect. Specifically, the laser frequency is synchronized with the atomic transition frequency in a reference saturated absorption cell using the Pound-Drever-Hall (PDH) frequency locking technique, achieving frequency stability within ±10 kHz.

[0053] The laser signal then enters an electro-optical modulator (EOM), where it undergoes phase modulation driven by an external RF signal (10.7 MHz). The modulation depth is dynamically adjusted by an FPGA controller to compensate for the modulator's nonlinear response, ensuring a stable modulation depth (within ±1%) for the modulated optical signal. The modulated optical signal carries a periodic phase perturbation signature, creating a probe signal highly sensitive to electromagnetic disturbances induced by partial discharges.

[0054] Step 2: Perform signal interaction and coupling;

[0055] The purpose of step 2 is to physically interact the atomic light signal with the electrical signal to be measured in a set space.

[0056] In a preferred but non-limiting embodiment of the present invention, in step 2, the modulated atomic optical signal is coupled with the electrical signal to be measured in a predetermined space. Specifically, the atomic optical signal and the electrical signal to be measured physically interact at the electromagnetic field level within the predetermined space (which can be free space or a waveguide structure). Partial discharge pulses that may be present in the electrical signal to be measured will alter the electromagnetic environment in that region, thereby modulating the propagation characteristics of the atomic optical signal, such as its phase, polarization state, or absorption intensity.

[0057] In a preferred but non-limiting embodiment of the present invention, in step 2, a high-bandwidth waveguide or open resonant cavity structure is employed within the designated space to enhance the interaction efficiency between the atomic optical signal and the electrical signal to be measured. Furthermore, an electromagnetic shielding structure is introduced within the designated space to suppress the influence of external interference signals. This coupling process ensures that the atomic optical signal responds to the partial discharge signal with high selectivity and repeatability. The atomic optical signal after interaction carries information related to the partial discharge disturbance in the measured signal, enabling subsequent detection and analysis.

[0058] In an embodiment of the present invention, the modulated atomic optical signal is guided along a waveguide propagation path to the detection area. Electromagnetic coupling is then achieved using an electromagnetic coupling device with the conductor structure (such as a high-voltage cable) containing the electrical signal to be measured. The electrical signal to be measured is the magnetic field signal of a 10 kV AC transmission line, with a potential partial discharge signal frequency range of 100 MHz to 1 GHz.

[0059] A coplanar waveguide structure is used as the electromagnetic coupling device. Atomic optical signals propagate along the waveguide path and interact with the electromagnetic field on the conductor. When a partial discharge event occurs in the line, the resulting transient electromagnetic pulse (typically lasting <1ns and with an amplitude of several V / m) disrupts the energy level structure of the atomic medium, thereby modulating the phase or polarization properties of the passing optical signal.

[0060] An electromagnetic shielding layer (made of μ-metal, with a shielding efficiency of >60 dB at 1 GHz) is incorporated into the electromagnetic coupling device structure to suppress the effects of environmental electromagnetic interference and improve the system's signal-to-noise ratio. Tests have shown that this structure can increase the sensitivity of electronic optical signals to partial discharge signals by approximately three times.

[0061] Step 3: Photoelectric detection and signal extraction;

[0062] The purpose of step 3 is to receive the electronic light signal after interaction and the original electrical signal to be measured through a photodetector and output a corresponding electrical signal.

[0063] In a preferred but non-limiting embodiment of the present invention, in step 3, a high-response balanced photodetector is used to receive the atomic light signal after interaction, while simultaneously introducing the original electrical signal to be measured as a reference channel, forming a differential detection structure. The photodetector converts the atomic light signal into an electrical signal, digitally samples it via a high-speed analog-to-digital converter (ADC), and transmits the digitally sampled data to an FPGA controller at a sampling rate of no less than 10 GS / s to capture the transient disturbance characteristics caused by partial discharge. The FPGA controller uses phase-locked amplification or digital orthogonal demodulation to demodulate the digitally sampled data of the modulated electronic light signal, extracting key parameters such as its amplitude, phase, or frequency offset. This step achieves highly sensitive detection of weak electromagnetic disturbances caused by partial discharge and converts the signal characteristics into analyzable digital data.

[0064] In a preferred but non-limiting embodiment of the present invention, in step 3, the atomic light signal after interaction enters a balanced photodetector, which is composed of two symmetrical PIN photodiodes. The two symmetrical PIN photodiodes form two optical paths, which can effectively suppress common mode noise; the output voltage signal of the balanced photodetector is It is proportional to the difference in light intensity between the two light paths and satisfies the following expression:

[0065]

[0066] in To balance the responsivity of the photodetector (unit: V / W), and are the incident light intensities of the atomic light signal on the two optical paths respectively.

[0067] This voltage signal then enters one channel of a high-speed analog-to-digital converter (ADC, sampling rate 10 GS / s, resolution 10 bits) for digital sampling. Simultaneously, the electrical signal to be measured is sampled synchronously in another channel of the high-speed ADC via a coupler. The synchronously sampled data of the measured electrical signal forms a dual-channel differential structure. By comparing the time-aligned data of the electronic optical signal and the measured electrical signal, the perturbation characteristics of the electronic optical signal response are extracted.

[0068] Step 4: Partial discharge feature analysis and identification.

[0069] The purpose of step 4 is to process the electrical signal output by the photodetector, extract characteristic parameters related to partial discharge, and determine whether a partial discharge signal exists.

[0070] In a preferred but non-limiting embodiment of the present invention, in step 4, the FPGA controller synchronously processes the sampled data of the received electronic light signal and the sampled data of the electrical signal to be measured, and extracts the following partial discharge characteristics as key features:

[0071] Transient amplitude change of electronic light signal , electronic optical signal phase shift The mutual correlation coefficient between the electronic light signal and the measured electrical signal .

[0072] In a preferred but non-limiting embodiment of the present invention, in step 4, the two channels of the high-speed analog-to-digital converter use a high-precision clock synchronization unit (time error <10 ps) to perform parallel data sampling on the electronic optical signal and the electrical signal to be measured, ensuring that the sampled data of the two signals are strictly aligned in the time domain;

[0073] Based on the variance analysis method, the transient amplitude change of the electronic light signal in the set period where partial discharge events may occur is extracted. , specifically including:

[0074] (1) Perform baseline calibration: Obtain the optical signal baseline during a set period without partial discharge. , The calculation formula is:

[0075] 𝐼

[0076] in The number of digitally sampled data of the electronic optical signal formed after modulation during the set period without partial discharge, The first digital sampling of the electronic light signal formed after modulation during the set period without partial discharge is arranged in the order of the sampling time. The amplitude value of each data;

[0077] (2) Transient detection: using variance analysis, first obtain the variance of the amplitude value of the digitally sampled data of the electronic light signal during the set period without partial discharge. , when the digital sampling of the electronic light signal during the set period of possible partial discharge event is arranged in the order of the sampling time, the first The amplitude value of the data exist When the It is determined to be a transient amplitude value and is defined as ;𝜎

[0078] (3) Transient amplitude change The calculation formula is:

[0079]

[0080] in To seek The maximum value of this method can effectively identify the sudden change characteristics of the electron optical signal caused by partial discharge.

[0081] The electronic optical signal formed after modulation is converted into in-phase and quadrature components by digital orthogonal demodulation method, and the phase offset of the electronic optical signal is calculated by four-quadrant inverse tangent algorithm. , which specifically include:

[0082] (1) Perform orthogonal demodulation: The electronic light signal formed after modulation is Digitally sampled data Perform quadrature demodulation, where is the frequency of the electronic light signal, The electronic light signal at time The phase, is the amplitude of the electronic light signal, and the moment is obtained after orthogonal demodulation The in-phase component and orthogonal components ;

[0083] (2) Phase extraction: Use the four-quadrant inverse tangent algorithm to calculate the time The instantaneous phase ;

[0084] (3) Calculate the phase offset of the electronic light signal ,in is the average of the instantaneous phases of all sampling moments of the electronic optical signal during the period in which a partial discharge event may occur, It is the average of the instantaneous phases of the electronic light signal at all sampling moments during a set period without partial discharge; a four-quadrant inverse tangent function is used to achieve high-precision phase calculation to ensure that the phase offset detection error is less than 0.1 rad.

[0085] Construct the cross-correlation function of the electronic light signal to obtain the cross-correlation coefficient between the electronic light signal and the electrical signal to be measured , which specifically include:

[0086] (1) Constructing the cross-correlation function of the electron-light signal ,in The first digitized sampling of the electronic light signal during the period of possible partial discharge event is arranged in the order of the sampling time. data, The first digitized sampling time of the electric signal to be measured is arranged in the order of the sampling time during the set period when partial discharge events may occur. data, The average value of the digital sampling of the electronic light signal during the set period where a partial discharge event may occur, which is arranged in the order of the sampling moments. The average of the digital samples of the electrical signal to be measured arranged in the order of their sampling moments during the set period in which a partial discharge event may occur;

[0087] (2) The mutual correlation coefficient between the electronic light signal and the measured electrical signal The calculation formula is ,in To seek The maximum value of this parameter Reflects the coupling strength between the electronic light signal and the measured electrical signal in a partial discharge event.

[0088] In a preferred but non-limiting embodiment of the present invention, in step 4, the transient amplitude change of the electronic light signal is , electronic optical signal phase shift The mutual correlation coefficient between the electronic light signal and the measured electrical signal After normalization, the data is input into the multi-layer perceptron (MLP) classifier. The MLP classifier adopts a three-layer structure: 3 nodes in the input layer, 10 nodes in the hidden layer, and 1 node in the output layer. The activation function is ReLU, and the output layer uses the Sigmoid function to generate the partial discharge probability value. , if the partial discharge probability value Higher than the set threshold , it is determined that partial discharge exists; otherwise, it is determined that partial discharge does not exist. The training data fed into the multi-layer perceptron (MLP) classifier in this embodiment of the present invention includes 100,000 sets of simulation data (including partial discharge models and interference signals), and the validation set accuracy rate is >99%. The final output is the judgment result of whether partial discharge exists or not. The set threshold Can be customized according to specific requirements, just as Set it to 0.75.

[0089] Verified by actual measured data, the method of the present invention successfully identified 97 partial discharge events in 100 tests, with a false alarm rate of less than 2%, which is significantly better than the traditional capacitive coupling detection method.

[0090] like Figure 2 As shown, the device for detecting partial discharge signals by atoms according to the present invention comprises:

[0091] The photodetector, the analog-to-digital converter and the FPGA controller are sequentially connected, and the analog-to-digital converter is also connected to the analog-to-digital converter;

[0092] The device for atomically detecting partial discharge signals further comprises:

[0093] A generation module, which is used to generate and modulate atomic light signals;

[0094] A coupling module, which is used for signal interaction and coupling;

[0095] Extraction module, which is used for photoelectric detection and signal extraction;

[0096] The identification module is used for partial discharge feature analysis and identification.

[0097] The beneficial effects of the present invention are that, compared with the prior art, the technical effects of the present invention include:

[0098] The present invention generates and modulates atomic optical signals; performs signal interaction and coupling; performs photoelectric detection and signal extraction; and analyzes and identifies partial discharge characteristics. This ensures high stability and repeatability of the atomic optical signals by constructing a closed-loop frequency stabilization and digital predistortion modulation system. A coplanar waveguide structure achieves efficient coupling of the electronic optical signal with the electrical signal to be measured. Combined with a dual-channel differential detection and feature extraction algorithm, partial discharge events can be effectively identified. This method offers advantages such as high sensitivity, strong interference resistance, and non-contact detection, making it suitable for practical applications such as high-voltage equipment status monitoring and online power system testing.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific implementation methods of the present invention can still be modified or replaced with equivalents, and any modifications or equivalent replacements that do not deviate from the spirit and scope of the present invention should be covered within the protection space of the claims of the present invention.

Claims

1. A method for detecting partial discharge signals by atomic force detection, characterized in that: include: Step 1: Generate and modulate atomic light signals; Step 2: Perform signal interaction and coupling; Step 3: Photoelectric detection and signal extraction; Step 4: Partial discharge feature analysis and identification; In step 1, a narrow linewidth laser is used to excite a specific atomic medium to generate an atomic resonance optical signal; An external electro-optical modulator is provided on the optical path of the atomic resonance light signal, and the atomic resonance light signal is modulated by the external electro-optical modulator. The atomic light signal formed after the modulation serves as a probe signal for physically interacting with the electrical signal to be measured; In step 2, the modulated atomic light signal is coupled with the electrical signal to be measured in a set space, that is, the atomic light signal and the electrical signal to be measured realize physical interaction at the electromagnetic field level through the set space; In step 2, an open resonant cavity structure is used in the set space to enhance the interaction efficiency between the atomic optical signal and the electrical signal to be measured, and an electromagnetic shielding structure is introduced in the set space; In step 3, a balanced photodetector is used to receive the atomic light signal after interaction, and the original electrical signal to be measured is simultaneously introduced as a reference channel to form a differential detection structure. The photodetector converts the atomic light signal into an electrical signal, digitally samples it through an analog-to-digital converter, and transmits the digitally sampled data to the FPGA controller. The FPGA controller uses phase-locked amplification or digital orthogonal demodulation to demodulate the digitally sampled data and extract its amplitude, phase, or frequency offset. In step 3, the balanced photodetector is composed of two symmetrical PIN photodiodes, and the two symmetrical PIN photodiodes form two optical paths; the output voltage signal of the balanced photodetector is It is proportional to the difference in light intensity between the two light paths and satisfies the following expression: in To balance the responsivity of the photodetector, and are the incident light intensities of the atomic light signal on the two light paths respectively; In step 4, the FPGA controller synchronously processes the sampled data of the received electronic light signal and the sampled data of the electrical signal to be measured, and extracts the following partial discharge characteristics as key features: Transient amplitude change of electronic light signal , electronic optical signal phase shift The mutual correlation coefficient between the electronic light signal and the measured electrical signal .

2. The method for detecting partial discharge signals by atomic force detection according to claim 1, characterized in that: In step 4, the two channels of the high-speed analog-to-digital converter use a high-precision clock synchronization unit to perform parallel data sampling on the electronic optical signal and the electrical signal to be measured; Based on the variance analysis method, the transient amplitude change of the electronic light signal in the set time period is extracted , specifically including: (1) Perform baseline calibration: Obtain the optical signal baseline during a set period without partial discharge. , The calculation formula is: in The number of digitally sampled data of the electronic optical signal during the set period without partial discharge, The first digital sampling of the electronic light signal during the set period without partial discharge The amplitude value of each data; (2) Transient detection: using variance analysis, first obtain the variance of the amplitude value of the digitally sampled data of the electronic light signal during the set period without partial discharge. , when the first digital sampling of the electronic light signal during the set period The amplitude value of the data exist When the It is determined to be a transient amplitude value and is defined as ; (3) Transient amplitude change The calculation formula is: in To seek The maximum value of The modulated electronic optical signal is converted into in-phase and quadrature components by digital quadrature demodulation method, and the phase offset of the electronic optical signal is calculated by four-quadrant inverse tangent algorithm. , which specifically include: (1) Perform orthogonal demodulation: The electronic light signal formed after modulation is Digitally sampled data Perform quadrature demodulation, where is the frequency of the electronic light signal, The electronic light signal at time The phase, is the amplitude of the electronic light signal, and the moment is obtained after orthogonal demodulation The in-phase component and orthogonal components ; (2) Phase extraction: Use the four-quadrant inverse tangent algorithm to calculate the time The instantaneous phase ; (3) Calculate the phase offset of the electronic light signal ,in is the average of the instantaneous phases of all sampling moments of the electronic light signal during the set period, is the average of the instantaneous phases of the electronic optical signal at all sampling moments during a set period without partial discharge; Construct the cross-correlation function of the electronic light signal to obtain the mutual correlation between the electronic light signal and the electrical signal to be measured. Relationship number , which specifically include: (1) Constructing the cross-correlation function of the electron-light signal ,in The first digital sampling of the electronic light signal during the set period data, The first digital sampling of the electrical signal to be measured during the set period data, is the average number of digitally sampled data of the electronic light signal during a set period of time, The average number of digitally sampled data of the electrical signal to be measured during a set period of time; (2) The mutual correlation coefficient between the electronic light signal and the measured electrical signal The calculation formula is ,in To seek The maximum value of .

3. The method for detecting partial discharge signals by atomic force detection according to claim 2, characterized in that: In step 4, the transient amplitude change of the electronic light signal , electronic optical signal phase shift The mutual correlation coefficient between the electronic light signal and the measured electrical signal After normalization, the data is input into the multi-layer perceptron classifier; the multi-layer perceptron classifier adopts a three-layer structure: 3 nodes in the input layer, 10 nodes in the hidden layer, and 1 node in the output layer. The activation function is ReLU, and the output layer uses the Sigmoid function to generate the partial discharge probability value. , if the partial discharge probability value Higher than the set threshold , it is determined that partial discharge exists, otherwise it is determined that no partial discharge exists.

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