Photoelectric cooperative detection method and system for partial discharge of power equipment

Abstract

The invention discloses a photoelectric cooperative detection method and system for partial discharge of power equipment, and the method comprises the steps: carrying out the partial discharge monitoring of the power equipment through a high-frequency current method, an ultrahigh frequency method and an optical detection method, and obtaining an HFCT standard signal, a UHF standard signal and a standard optical signal through data processing; shearing the HFCT standard signal and the UHF standard signal based on the standard optical signal to obtain an HFCT detection signal and a UHF detection signal; performing discrete Fourier transform and signal fusion on the HFCT detection signal and the UHF detection signal to obtain a frequency spectrum fusion coefficient, and performing inverse discrete Fourier transform on the frequency spectrum fusion coefficient to obtain a time domain fusion signal; drawing a partial discharge monitoring graph of the power equipment according to the time domain fusion signal; the method has sensitivity, anti-electromagnetic interference performance and accuracy at the same time, and the detection efficiency of the partial discharge of the power equipment is improved.

Description

Technical Field

[0001] The present invention belongs to the field of partial discharge detection of power equipment, and particularly relates to an optoelectronic collaborative detection method and system for partial discharge of power equipment. Background Art

[0002] In the power system, the insulation performance of power main equipment is crucial. However, due to the compact internal space, complex structure, and small insulation design margin, insulation defects or weak points such as impurities, spikes, and suspensions will inevitably be formed during production, transportation, assembly, and operation. Under the action of a strong electric field, these internal defects will cause uneven electric field distribution inside the insulation, increasing the electric field strength in the local area of the defect, thus easily triggering a discharge phenomenon that does not penetrate the entire insulation, namely partial discharge. Partial discharge is a key indication of equipment insulation deterioration and seriously threatens the safe operation of the equipment.

[0003] Currently, common partial discharge detection methods include high-frequency current method (HFCT), ultra-high frequency method (UHF), optical detection method, etc. HFCT is easily affected by on-site electromagnetic interference, and the accuracy of the detection signal will decrease significantly in a complex electromagnetic environment. The optical detection method is seriously affected by ambient light interference and it is difficult to work accurately under outdoor strong light or complex lighting conditions. The UHF signal attenuates rapidly during propagation, and has high requirements for sensor layout and signal transmission. Traditional one or more detection methods only simply measure various signals and do not combine the advantages of different detection technologies. In complex working conditions, a single detection means may have the problem of data insensitivity, resulting in poor detection effects and even possible omission of important fault information. Summary of the Invention

[0004] The present invention provides an optoelectronic collaborative detection method and system for partial discharge of power equipment, which combines the high-frequency current method (HFCT), ultra-high frequency method (UHF), and optical detection method to make up for each other's advantages in terms of sensitivity, anti-electromagnetic interference, and accuracy, and improve the detection efficiency of partial discharge of power equipment.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The first aspect of the present invention provides an optoelectronic collaborative detection method for partial discharge of power equipment, including:

[0007] Monitoring partial discharge of power equipment by the high-frequency current method, ultra-high frequency method, and optical detection method to obtain HFCT initial signal, UHF initial signal, and initial optical signal;

[0008] Preprocess and normalize the HFCT initial signal, UHF initial signal, and initial optical signal to obtain the HFCT standard signal, UHF standard signal, and standard optical signal. Determine the starting time of the partial discharge based on the standard optical signal, and clip the HFCT standard signal and UHF standard signal according to the starting time of the partial discharge to obtain the HFCT detection signal and UHF detection signal;

[0009] Perform discrete Fourier transform on the HFCT detection signal and UHF detection signal to obtain the HFCT frequency-domain signal and UHF frequency-domain signal. Fuse the HFCT frequency-domain signal and UHF frequency-domain signal to obtain the spectrum fusion coefficient, and perform inverse discrete Fourier transform on the spectrum fusion coefficient to obtain the time-domain fusion signal; Draw the partial discharge monitoring diagram of the power equipment according to the time-domain fusion signal.

[0010] Further, perform partial discharge monitoring on the power equipment by the high-frequency current method to obtain the HFCT initial signal, specifically including:

[0011] When partial discharge occurs inside the power equipment, a high-frequency pulse current is generated. The alternating magnetic field generated by the high-frequency current is sensed by the HFCT sensor to obtain an induced voltage signal. After filtering the induced voltage signal, it is sent to a broadband amplifier to obtain the HFCT initial signal.

[0012] Further, perform partial discharge monitoring on the power equipment by the ultra-high-frequency method to obtain the UHF initial signal, specifically including:

[0013] When partial discharge occurs inside the power equipment, a high-frequency pulse current is generated. The ultra-high-frequency electromagnetic wave radiated by the high-frequency pulse current is detected by the ultra-high-frequency sensor to obtain an electromagnetic wave induction signal. The electromagnetic wave induction signal is sent to a band-pass filter to remove noise to obtain the UHF initial signal.

[0014] Further, perform partial discharge monitoring on the power equipment by the optical detection method to obtain the initial optical signal, specifically including:

[0015] When partial discharge occurs inside the power equipment, light radiation is generated. The initial optical signal is detected by a selected micro-light sensor in the micro-light sensor matrix;

[0016] Record the background noise of the micro-light sensor and the dark count of the detection excitation event; Monitor the operating temperature of the micro-light sensor by a temperature sensor, and dynamically adjust the thresholds of the background noise and dark count according to the operating temperature. The threshold of the background noise is denoted as threshold P1, and the threshold of the dark count is threshold P2;

[0017] In response to the background noise reaching threshold P1, the dark count reaching threshold P2, or the operating temperature of the micro-light sensor reaching a preset temperature threshold, switch the micro-light sensor in the micro-light sensor matrix that detects the light radiation.

[0018] Further, the HFCT initial signal, the UHF initial signal and the initial optical signal are preprocessed, specifically including:

[0019] Identify and judge the missing values ​​in the HFCT initial signal, the UHF initial signal and the initial optical signal, and use the interpolation method to supplement the missing values;

[0020] The Z-Score method or the quartile method is used to identify whether there are outliers in the HFCT initial signal, the UHF initial signal and the initial optical signal; the outliers are eliminated from the HFCT initial signal, the UHF initial signal and the initial optical signal, and the adjacent normal values ​​are used to replace the outliers.

[0021] Furthermore, the HFCT frequency domain signal and the UHF frequency domain signal are fused to obtain a spectrum fusion coefficient, which specifically includes:

[0022]

[0023] In the formula, is the spectrum fusion coefficient; is the HFCT frequency domain signal; It is a UHF frequency domain signal; is the turning frequency point; k is the frequency index; is the weight of the jth spectral coefficient.

[0024] Furthermore, the weights of the spectrum coefficients are calculated, specifically including:

[0025] The frequency index value range of HFCT frequency domain signal is recorded as ; The frequency index value range of UHF frequency domain signal is recorded as ;

[0026] The turning frequency point is calculated according to the frequency index value range of the HFCT frequency domain signal and the UHF frequency domain signal. The expression formula is:

[0027]

[0028] when When the HFCT spectrum matrix is ​​generated according to the jth spectrum coefficient in the i-th partial discharge of the power equipment ,when When the UHF spectrum matrix is ​​generated according to the jth spectrum coefficient in the i-th partial discharge of the power equipment ;

[0029] Calculate HFCT spectrum matrix The weight of each spectral coefficient in generates the HFCT weight matrix ; Calculate UHF spectrum matrix Generate a UHF proportion matrix based on the proportions of each spectrum coefficient ;

[0030] According to the HFCT proportion matrix and the HFCT proportion matrix Calculate the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal, and calculate the weights of the HFCT frequency-domain signal and the UHF frequency-domain signal from the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal.

[0031] The second aspect of the present invention provides an optoelectronic collaborative detection system for partial discharge of power equipment, including:

[0032] An acquisition module for monitoring partial discharge of power equipment by high-frequency current method, ultra-high frequency method and optical detection method to obtain HFCT initial signal, UHF initial signal and initial optical signal;

[0033] A preprocessing module for preprocessing and normalizing the HFCT signal, UHF signal and optical signal to obtain HFCT standard signal, UHF standard signal and standard optical signal;

[0034] A signal division module for determining the starting time of the partial discharge based on the standard optical signal, and clipping the HFCT standard signal and the UHF standard signal according to the starting time of the partial discharge to obtain HFCT detection signal and UHF detection signal;

[0035] A signal fusion module for performing discrete Fourier transform on the HFCT detection signal and the UHF detection signal to obtain HFCT frequency-domain signal and UHF frequency-domain signal, and fusing the HFCT frequency-domain signal and the UHF frequency-domain signal to obtain spectrum fusion coefficients;

[0036] An identification and output module for performing inverse discrete Fourier transform on the spectrum fusion coefficients to obtain a time-domain fusion signal; and drawing a partial discharge monitoring diagram of the power equipment according to the time-domain fusion signal.

[0037] Furthermore, it further includes a low-light sensor, an ultra-high frequency sensor, an HFCT sensor and a detection platform; the low-light sensor, the ultra-high frequency sensor and the HFCT sensor are electrically connected to a computer through a high-speed acquisition card;

[0038] The HFCT sensor senses the alternating magnetic field generated by partial discharge to obtain an induced voltage signal; the ultra-high frequency sensor detects the ultra-high frequency electromagnetic wave generated by partial discharge to obtain an electromagnetic wave induction signal; the low-light sensor matrix detects the light radiation generated by partial discharge to obtain an initial optical signal;

[0039] The power supply, water resistor, resistor-capacitor divider, high-speed acquisition card, and computer are electrically connected in sequence; the housing of the detection platform is connected to the circuit between the water resistor and the resistor-capacitor divider, and the housing of the detection platform is grounded; a grounding resistor is connected to the circuit between the resistor-capacitor divider and the high-speed acquisition card.

[0040] Further, it also includes: when partial discharge occurs inside the power equipment, light radiation is generated, and the initial optical signal is obtained by detecting the light radiation with a selected micro-light sensor in the micro-light sensor matrix; the micro-light sensor matrix is electrically connected to the microcontroller unit through a multiplexer;

[0041] The microcontroller unit records the background noise of the micro-light sensor and the dark count of the detection excitation event; the working temperature of the micro-light sensor is monitored through a temperature sensor, and the thresholds of the background noise and the dark count are dynamically adjusted according to the working temperature. The threshold of the background noise is denoted as threshold P1, and the threshold of the dark count is threshold P2;

[0042] In response to the background noise reaching threshold P1, the dark count reaching threshold P2, or the working temperature of the micro-light sensor reaching the preset temperature threshold, the microcontroller unit controls the micro-light sensor in the micro-light sensor matrix that detects the light radiation to switch.

[0043] Further, the signal fusion module fuses the HFCT frequency-domain signal and the UHF frequency-domain signal to obtain the spectrum fusion coefficient, specifically including:

[0044]

[0045] In the formula, is the spectrum fusion coefficient; is the HFCT frequency-domain signal; is the UHF frequency-domain signal; is the turning frequency point; k is the frequency index; is the weight of the jth spectrum coefficient.

[0046] Further, the signal fusion module calculates the weight of the spectrum coefficient, specifically including:

[0047] The value range of the frequency index of the HFCT frequency-domain signal is denoted as ; the value range of the frequency index of the UHF frequency-domain signal is denoted as ;

[0048] The turning frequency point is calculated according to the value ranges of the frequency indices of the HFCT frequency-domain signal and the UHF frequency-domain signal, and the expression formula is:

[0049]

[0050] When When, generate the HFCT spectrum matrix according to the j-th spectrum coefficient in the i-th partial discharge of the power equipment When When, generate the UHF spectrum matrix according to the j-th spectrum coefficient in the i-th partial discharge of the power equipment ;

[0051] Calculate the proportion of each spectrum coefficient in the HFCT spectrum matrix to generate the HFCT proportion matrix ; Calculate the proportion of each spectrum coefficient in the UHF spectrum matrix to generate the UHF proportion matrix ;

[0052] According to the HFCT proportion matrix and the HFCT proportion matrix Calculate the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal, and calculate the weights of the HFCT frequency-domain signal and the UHF frequency-domain signal from the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal.

[0053] The third aspect of the present invention provides an electronic device, including a storage medium and a processor; the storage medium is used to store instructions; characterized in that the processor is used to operate according to the instructions to execute the optoelectronic collaborative detection method described in the first aspect.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0055] In the present invention, the starting time of the partial discharge is determined based on the standard optical signal, and the HFCT standard signal and the UHF standard signal are clipped according to the starting time of the partial discharge to obtain the HFCT detection signal and the UHF detection signal; the HFCT detection signal and the UHF detection signal are subjected to discrete Fourier transform and inverse discrete Fourier transform of signal fusion to obtain the time-domain fusion signal; the partial discharge monitoring map of the power equipment is drawn according to the time-domain fusion signal; a measurement system of multi-physical synchronous sensing is constructed, and the optoelectronic signals are synergistically processed through time-frequency domain conversion superposition to obtain a more complete partial discharge signal, giving full play to the significant complementary advantages of optoelectronic sensing technology in sensitivity, anti-electromagnetic interference and accuracy. Description of the Drawings

[0056] Figure 1 is a flowchart of an optoelectronic collaborative detection method for partial discharge of power equipment provided in Embodiment 1;

[0057] Figure 2 is a flowchart of switching a low-light sensor provided in Embodiment 1;

[0058] Figure 3 is an electrode structure diagram of simulated discharge provided in Embodiment 1;

[0059] Figure 4 is the PD waveform diagram of the partial discharge of the tip discharge defect provided in Embodiment 1;

[0060] Figure 5 is the structural diagram of an optoelectronic collaborative detection system for partial discharge of power equipment provided in Embodiment 2;

[0061] Figure 6 is the structural diagram of the low-light sensor matrix provided in Embodiment 2. Detailed implementation manners

[0062] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0063] Embodiment 1

[0064] As Figure 1 shown, the present embodiment provides an optoelectronic collaborative detection method for partial discharge of power equipment, including

[0065] monitoring the partial discharge of the power equipment by the high-frequency current method to obtain the HFCT initial signal, specifically including:

[0066] When partial discharge occurs inside the power equipment, a high-frequency pulse current is generated. The alternating magnetic field generated by the high-frequency current is sensed by the HFCT sensor to obtain an induced voltage signal. After filtering the induced voltage signal, it is sent to a broadband amplifier to obtain the HFCT initial signal.

[0067] monitoring the partial discharge of the power equipment by the ultra-high-frequency method to obtain the UHF initial signal, specifically including:

[0068] When partial discharge occurs inside the power equipment, a high-frequency pulse current is generated. The ultra-high-frequency electromagnetic wave radiated by the high-frequency pulse current is detected by the ultra-high-frequency sensor to obtain an electromagnetic wave induction signal. The electromagnetic wave induction signal is sent to a band-pass filter to remove noise to obtain the UHF initial signal.

[0069] monitoring the partial discharge of the power equipment by the optical detection method to obtain the initial optical signal, specifically including:

[0070] When partial discharge occurs inside the power equipment, light radiation is generated. The light radiation is detected by the selected low-light sensor (SiPM unit) in the low-light sensor matrix to obtain the initial optical signal;

[0071] As Figure 2As shown, record the background noise of the low-light sensor and the dark count of detecting excitation events; monitor the operating temperature of the low-light sensor through a temperature sensor, and dynamically adjust the thresholds of the background noise and the dark count according to the operating temperature. The threshold of the background noise is denoted as threshold P1, and the threshold of the dark count is threshold P2;

[0072] In response to the background noise reaching threshold P1, the dark count reaching threshold P2, or the operating temperature of the low-light sensor reaching a preset temperature threshold, switch the low-light sensors in the low-light sensor matrix that detect optical radiation.

[0073] Preprocess the HFCT initial signal, UHF initial signal, and initial optical signal, specifically including:

[0074] Identify and judge the missing values in the HFCT initial signal, UHF initial signal, and initial optical signal, and use the interpolation method to supplement the missing values;

[0075] Use the Z-Score method or the quartile method to identify whether there are outliers in the HFCT initial signal, UHF initial signal, and initial optical signal; remove the outliers from the HFCT initial signal, UHF initial signal, and initial optical signal, and use the adjacent normal values to replace the outliers.

[0076] After preprocessing the HFCT initial signal, UHF initial signal, and initial optical signal, perform normalization processing to obtain the HFCT standard signal, UHF standard signal, and standard optical signal. The expression formula is:

[0077]

[0078] In the formula, is the HFCT standard signal; is the HFCT initial signal; is the maximum value of the HFCT initial signal; is the minimum value of the HFCT initial signal; is the UHF standard signal; is the UHF initial signal; is the maximum value of the UHF initial signal; is the minimum value of the UHF initial signal; is the standard optical signal; is the initial optical signal; is the maximum value of the initial optical signal; is the minimum value of the initial optical signal;

[0079] Based on the standard optical signal, determine the starting time of the partial discharge, and shear the HFCT standard signal and UHF standard signal according to the starting time of the partial discharge to obtain the HFCT detection signal and UHF detection signal;

[0080] The HFCT detection signal and the UHF detection signal are subjected to discrete Fourier transform to obtain the HFCT frequency-domain signal and the UHF frequency-domain signal. The expression formula is as follows:

[0081]

[0082]

[0083] In the formula, N is the length of the HFCT detection signal or the UHF detection signal; j is the sequence number of the spectral coefficient; n is the number of partial discharges; k is the frequency index; is the HFCT frequency-domain signal; is the UHF frequency-domain signal; is the HFCT detection signal; is the UHF detection signal.

[0084] The HFCT frequency-domain signal and the UHF frequency-domain signal are fused to obtain the spectral fusion coefficient, which specifically includes:

[0085]

[0086] In the formula, is the spectral fusion coefficient; is the HFCT frequency-domain signal; is the UHF frequency-domain signal; is the turning frequency point; k is the frequency index; is the weight of the j-th spectral coefficient.

[0087] Calculate the weight of the spectral coefficient, which specifically includes:

[0088] The value range of the frequency index of the HFCT frequency-domain signal is denoted as ; The value range of the frequency index of the UHF frequency-domain signal is denoted as ;

[0089] Calculate the turning frequency point according to the value ranges of the frequency indices of the HFCT frequency-domain signal and the UHF frequency-domain signal. The expression formula is:

[0090]

[0091] When , generate the HFCT spectral matrix according to the j-th spectral coefficient in the i-th partial discharge of the power equipment. When , generate the UHF spectral matrix according to the j-th spectral coefficient in the i-th partial discharge of the power equipment; The expression formula is:

[0092]

[0093] In the formula, is the element in the HFCT spectrum matrix or the UHF spectrum matrix ; is the j-th spectrum coefficient in the i-th partial discharge; and are the maximum and minimum values of the spectrum coefficients.

[0094] Calculate the proportion of each spectrum coefficient in the HFCT spectrum matrix to generate the HFCT proportion matrix ; Calculate the proportion of each spectrum coefficient in the UHF spectrum matrix to generate the UHF proportion matrix ; The expression formula is:

[0095]

[0096] In the formula, is the element in the HFCT proportion matrix or the UHF proportion matrix ; m is the maximum value of the spectrum order.

[0097] According to the HFCT proportion matrix and the HFCT proportion matrix calculate the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal, and calculate the weights of the HFCT frequency-domain signal and the UHF frequency-domain signal from the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal. The expression formula is:

[0098]

[0099]

[0100]

[0101] In the formula, is the weight of the j-th spectrum coefficient, is the entropy value of the HFCT frequency-domain signal or the UHF frequency-domain signal.

[0102] Perform inverse discrete Fourier transform on the spectrum fusion coefficient to obtain the time-domain fusion signal; draw the partial discharge monitoring diagram of the power equipment according to the time-domain fusion signal.

[0103] In this embodiment, a measurement system for multi-physical synchronous sensing is constructed, and the optoelectronic signals are cooperatively processed through time-frequency domain conversion and superposition to obtain a more complete partial discharge signal, giving full play to the significant complementary advantages of optoelectronic sensing technology in terms of sensitivity, anti-electromagnetic interference, and accuracy.

[0104] Such asFigure 3 As shown in the figure, in this embodiment, the metal tip discharge model, the insulating air gap discharge model, the insulating surface discharge model, and the metal floating potential discharge model are used for partial discharge simulation; specifically, it includes:

[0105] Tip discharge model: The diameter of the rod part of the needle electrode is 6 mm, the tip is conical, the equivalent curvature radius of the tip is 50 μm, and the distance between the tip of the needle electrode and the plate electrode is adjustable.

[0106] Air gap discharge model: There is an air gap of about 1 mm in the epoxy resin block between the two plate electrodes.

[0107] Surface discharge model: The diameter of the high-voltage rod electrode is 6 mm, and the thickness of the epoxy resin insulating plate is 2 mm, which is clamped between the rod and plate electrodes.

[0108] Floating discharge model: The upper part is the high-voltage electrode, the floating electrode is fixed between the electrodes, with a diameter of 4 mm, the equivalent curvature radius of the electrode tip is 50 μm, the cone angle is 50°, and the distance between the tip and the plate electrode is adjustable.

[0109] As Figure 4 shown, the partial discharge of the tip discharge defect is tested, and the results prove that the waveform of the optoelectronic collaborative detection and processing of the partial discharge signal is more real. Due to strong electronegativity, the pulse width of the PD waveform in SF6 gas is significantly narrower, and the current drops faster.

[0110] Embodiment 2

[0111] As Figure 5 shown, this embodiment discloses an optoelectronic collaborative detection system for partial discharge of power equipment. The optoelectronic collaborative detection system is used to execute the optoelectronic collaborative detection method described in Embodiment 1. The optoelectronic collaborative detection system includes:

[0112] An acquisition module, which is used to monitor partial discharge of power equipment through the high-frequency current method, the ultra-high frequency method, and the optical detection method to obtain HFCT initial signals, UHF initial signals, and initial optical signals;

[0113] A preprocessing module, which is used to preprocess and normalize the HFCT signal, the UHF signal, and the optical signal to obtain HFCT standard signals, UHF standard signals, and standard optical signals,

[0114] A signal division module, which is used to determine the starting time of the partial discharge based on the standard optical signal, and clip the HFCT standard signal and the UHF standard signal according to the starting time of the partial discharge to obtain HFCT detection signals and UHF detection signals;

[0115] A signal fusion module, which is used to perform discrete Fourier transform on the HFCT detection signal and the UHF detection signal to obtain the HFCT frequency-domain signal and the UHF frequency-domain signal, and fuse the HFCT frequency-domain signal and the UHF frequency-domain signal to obtain a spectrum fusion coefficient.

[0116] An identification and output module, which is used to perform inverse discrete Fourier transform on the spectrum fusion coefficient to obtain a time-domain fusion signal; and draw a partial discharge monitoring map of the power equipment according to the time-domain fusion signal.

[0117] The signal fusion module fuses the HFCT frequency-domain signal and the UHF frequency-domain signal to obtain a spectrum fusion coefficient, specifically including:

[0118]

[0119] In the formula, is the spectrum fusion coefficient; is the HFCT frequency-domain signal; is the UHF frequency-domain signal; is the turning frequency point; k is the frequency index; is the weight of the jth spectrum coefficient.

[0120] The signal fusion module calculates the weight of the spectrum coefficient, specifically including:

[0121] The value range of the frequency index of the HFCT frequency-domain signal is denoted as ; the value range of the frequency index of the UHF frequency-domain signal is denoted as ;

[0122] Calculate the turning frequency point according to the value ranges of the frequency indexes of the HFCT frequency-domain signal and the UHF frequency-domain signal. The expression formula is:

[0123]

[0124] When , generate the HFCT spectrum matrix according to the jth spectrum coefficient in the ith partial discharge of the power equipment. When , generate the UHF spectrum matrix according to the jth spectrum coefficient in the ith partial discharge of the power equipment;

[0125] Calculate the proportion of each spectrum coefficient in the HFCT spectrum matrix to generate the HFCT proportion matrix ; calculate the proportion of each spectrum coefficient in the UHF spectrum matrix to generate the UHF proportion matrix ;

[0126] According to the HFCT proportion matrix and the HFCT specific gravity matrix Calculate the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal, and calculate the weights of the HFCT frequency-domain signal and the UHF frequency-domain signal from the entropy values of the HFCT frequency-domain signal and the UHF frequency-domain signal.

[0127] The optoelectronic collaborative detection system further includes a low-light sensor, a UHF sensor, an HFCT sensor, and a detection platform; the low-light sensor, the UHF sensor, and the HFCT sensor are electrically connected to a computer through a high-speed acquisition card;

[0128] The HFCT sensor senses the alternating magnetic field generated by partial discharge to obtain an induced voltage signal; the UHF sensor detects the UHF electromagnetic wave generated by partial discharge to obtain an electromagnetic wave induction signal; the low-light sensor matrix detects the light radiation generated by partial discharge to obtain an initial light signal; the structure of the low-light sensor matrix is as Figure 6 shown,

[0129] The power supply, the water resistor, the capacitive voltage divider, the high-speed acquisition card, and the computer are electrically connected in sequence; the housing of the detection platform is connected to the circuit between the water resistor and the capacitive voltage divider, and the housing of the detection platform is grounded; a grounding resistor is connected to the circuit between the capacitive voltage divider and the high-speed acquisition card.

[0130] When partial discharge occurs inside the power equipment, light radiation is generated, and the selected low-light sensor in the low-light sensor matrix detects the light radiation to obtain an initial light signal; the low-light sensor matrix is electrically connected to the microcontroller unit through a multiplexer;

[0131] The microcontroller unit records the background noise of the low-light sensor and the dark count of the detection excitation event; monitors the operating temperature of the low-light sensor through a temperature sensor, and dynamically adjusts the thresholds of the background noise and the dark count according to the operating temperature. The threshold of the background noise is denoted as threshold P1, and the threshold of the dark count is threshold P2;

[0132] In response to the background noise reaching threshold P1, the dark count reaching threshold P2, or the operating temperature of the low-light sensor reaching a preset temperature threshold, the microcontroller unit controls the low-light sensor that detects light radiation in the low-light sensor matrix to switch.

[0133] Embodiment 3

[0134] This embodiment provides an electronic device, including a storage medium and a processor; the storage medium is used to store instructions; characterized in that the processor is used to operate according to the instructions to execute the optoelectronic collaborative detection method described in Embodiment 1.

[0135] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0136] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or a plurality of flows and / or blocks

[0137] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in Figure 1 one or more of the flows Figure 1 or a plurality of flows and / or blocks

[0138] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or a plurality of flows and / or blocks

[0139] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A photoelectric cooperative detection method for partial discharge of power equipment, characterized in that: include: The partial discharge monitoring of power equipment is carried out by high-frequency current method, ultra-high frequency method and optical detection method to obtain HFCT initial signal, UHF initial signal and initial optical signal; Preprocessing and normalizing the HFCT initial signal, the UHF initial signal and the initial optical signal to obtain the HFCT standard signal, the UHF standard signal and the standard optical signal, determining the starting time of the partial discharge based on the standard optical signal, and shearing the HFCT standard signal and the UHF standard signal according to the starting time of the partial discharge to obtain the HFCT detection signal and the UHF detection signal; Performing discrete Fourier transform on the HFCT detection signal and the UHF detection signal to obtain HFCT frequency domain signal and UHF frequency domain signal, fusing the HFCT frequency domain signal and the UHF frequency domain signal to obtain spectrum fusion coefficients, performing inverse discrete Fourier transform on the spectrum fusion coefficients to obtain time domain fusion signals; and drawing a partial discharge monitoring diagram of the power equipment according to the time domain fusion signal.

2. The optoelectronic collaborative detection method according to claim 1, characterized in that: The HFCT initial signal is obtained by monitoring partial discharge of power equipment through high-frequency current method, including: When partial discharge occurs inside the power equipment, a high-frequency pulse current is generated. The HFCT sensor senses the alternating magnetic field generated by the high-frequency current to obtain an induced voltage signal. The induced voltage signal is filtered and sent to a broadband amplifier to obtain an HFCT initial signal.

3. The optoelectronic cooperative detection method according to claim 1, characterized in that: The UHF initial signal is obtained by monitoring partial discharge of power equipment through the ultra-high frequency method, including: When partial discharge occurs inside the power equipment, a high-frequency pulse current is generated. The ultra-high frequency electromagnetic wave radiated by the high-frequency pulse current is detected by an ultra-high frequency sensor to obtain an electromagnetic wave induction signal, which is then sent to a bandpass filter to remove noise and obtain a UHF initial signal.

4. The optoelectronic cooperative detection method according to claim 1, characterized in that: The initial optical signal is obtained by performing partial discharge monitoring on power equipment through optical detection method, including: When partial discharge occurs inside the power equipment, light radiation is generated, and the initial light signal is obtained by detecting the light radiation through a selected low-light sensor in the low-light sensor matrix; Recording the background noise of the twilight sensor and the dark count of the detection excitation event; monitoring the operating temperature of the twilight sensor through a temperature sensor, and dynamically adjusting the thresholds of the background noise and the dark count according to the operating temperature, the threshold of the background noise is recorded as threshold P1, and the threshold of the dark count is recorded as threshold P2; In response to the background noise reaching the threshold value P1, the dark count reaching the threshold value P2, or the operating temperature of the low-light sensor reaching the preset temperature threshold, the low-light sensor in the low-light sensor matrix that detects light radiation is switched.

5. The optoelectronic cooperative detection method according to claim 1, characterized in that: The HFCT initial signal, the UHF initial signal and the initial optical signal are preprocessed, specifically including: Identify and judge the missing values ​​in the HFCT initial signal, the UHF initial signal and the initial optical signal, and use the interpolation method to supplement the missing values; The Z-Score method or the quartile method is used to identify whether there are outliers in the HFCT initial signal, the UHF initial signal and the initial optical signal; the outliers are eliminated from the HFCT initial signal, the UHF initial signal and the initial optical signal, and the adjacent normal values ​​are used to replace the outliers.

6. The optoelectronic cooperative detection method according to claim 1, characterized in that: The HFCT frequency domain signal and the UHF frequency domain signal are fused to obtain the spectrum fusion coefficient, which specifically includes: ； In the formula, is the spectrum fusion coefficient; is the HFCT frequency domain signal; It is a UHF frequency domain signal; is the turning frequency point; k is the frequency index; is the weight of the jth spectral coefficient.

7. The optoelectronic cooperative detection method according to claim 6, characterized in that: Calculate the weights of the spectral coefficients, including: The frequency index value range of HFCT frequency domain signal is recorded as ; The frequency index value range of UHF frequency domain signal is recorded as ; The turning frequency point is calculated according to the frequency index value range of the HFCT frequency domain signal and the UHF frequency domain signal. The expression formula is: ； when When the HFCT spectrum matrix is ​​generated according to the jth spectrum coefficient in the i-th partial discharge of the power equipment ,when When the UHF spectrum matrix is ​​generated according to the jth spectrum coefficient in the i-th partial discharge of the power equipment ; Calculate HFCT spectrum matrix The weight of each spectral coefficient in generates the HFCT weight matrix ; Calculate UHF spectrum matrix The weight of each spectrum coefficient in generates the UHF weight matrix ; According to the HFCT specific gravity matrix and HFCT density matrix The entropy values ​​of the HFCT frequency domain signal and the UHF frequency domain signal are calculated, and the weights of the HFCT frequency domain signal and the UHF frequency domain signal are calculated according to the entropy values ​​of the HFCT frequency domain signal and the UHF frequency domain signal.

8. A photoelectric cooperative detection system for partial discharge of power equipment, characterized in that: include: An acquisition module is used to perform partial discharge monitoring on power equipment by high-frequency current method, ultra-high frequency method and optical detection method to obtain HFCT initial signal, UHF initial signal and initial optical signal; A preprocessing module is used to preprocess and normalize the HFCT signal, the UHF signal and the optical signal to obtain the HFCT standard signal, the UHF standard signal and the standard optical signal; A signal division module, used for determining the starting time of the partial discharge based on the standard optical signal, and cutting the HFCT standard signal and the UHF standard signal according to the starting time of the partial discharge to obtain the HFCT detection signal and the UHF detection signal; A signal fusion module is used to perform discrete Fourier transform on the HFCT detection signal and the UHF detection signal to obtain the HFCT frequency domain signal and the UHF frequency domain signal, and fuse the HFCT frequency domain signal and the UHF frequency domain signal to obtain a spectrum fusion coefficient; The identification output module is used to perform inverse discrete Fourier transform on the spectrum fusion coefficient to obtain a time domain fusion signal; and draw a partial discharge monitoring diagram of the power equipment according to the time domain fusion signal.

9. The optoelectronic cooperative detection system according to claim 8, characterized in that: It includes a low light sensor, an ultra-high frequency sensor, an HFCT sensor and a detection platform; the low light sensor, the ultra-high frequency sensor and the HFCT sensor are electrically connected to a computer through a high-speed acquisition card; The HFCT sensor senses the alternating magnetic field generated by partial discharge to obtain an induced voltage signal; the ultra-high frequency sensor detects the ultra-high frequency electromagnetic wave generated by partial discharge to obtain an electromagnetic wave induction signal; the micro-light sensor matrix detects the light radiation generated by partial discharge to obtain an initial light signal; The power supply, water resistor, RC voltage divider, high-speed acquisition card and computer are electrically connected in sequence; the circuit between the water resistor and the RC voltage divider is connected to the shell of the detection platform, and the shell of the detection platform is grounded; the circuit between the RC voltage divider and the high-speed acquisition card is connected to the grounding resistor.

10. The optoelectronic cooperative detection system according to claim 9, characterized in that: Also includes: When partial discharge occurs inside the power equipment, light radiation is generated, and the initial light signal is obtained by detecting the light radiation through a selected low-light sensor in the low-light sensor matrix; The low-light sensor matrix is ​​electrically connected to the microcontroller unit via a multiplexer; The microcontroller unit records the background noise of the low-light sensor and the dark count of the detection excitation event; the operating temperature of the low-light sensor is monitored by a temperature sensor, and the thresholds of the background noise and the dark count are dynamically adjusted according to the operating temperature, the threshold of the background noise is recorded as threshold P1, and the threshold of the dark count is recorded as threshold P2; In response to the background noise reaching the threshold value P1, the dark count reaching the threshold value P2, or the operating temperature of the low-light sensor reaching the preset temperature threshold, the microcontroller unit controls the low-light sensors detecting light radiation in the low-light sensor matrix to switch.

11. The optoelectronic cooperative detection system according to claim 8, characterized in that: The signal fusion module fuses the HFCT frequency domain signal and the UHF frequency domain signal to obtain a spectrum fusion coefficient, specifically including: ； In the formula, is the spectrum fusion coefficient; is the HFCT frequency domain signal; It is a UHF frequency domain signal; is the turning frequency point; k is the frequency index; is the weight of the jth spectral coefficient.

12. The optoelectronic cooperative detection system according to claim 11, characterized in that: The signal fusion module calculates the weight of the spectrum coefficient, specifically including: The frequency index value range of HFCT frequency domain signal is recorded as ; The frequency index value range of UHF frequency domain signal is recorded as ; The turning frequency point is calculated according to the frequency index value range of the HFCT frequency domain signal and the UHF frequency domain signal. The expression formula is: ； when When the HFCT spectrum matrix is ​​generated according to the jth spectrum coefficient in the i-th partial discharge of the power equipment ,when When the UHF spectrum matrix is ​​generated according to the jth spectrum coefficient in the i-th partial discharge of the power equipment ; Calculate HFCT spectrum matrix The weight of each spectral coefficient in generates the HFCT weight matrix ; Calculate UHF spectrum matrix The weight of each spectrum coefficient in generates the UHF weight matrix ; According to the HFCT specific gravity matrix and HFCT density matrix The entropy values ​​of the HFCT frequency domain signal and the UHF frequency domain signal are calculated, and the weights of the HFCT frequency domain signal and the UHF frequency domain signal are calculated according to the entropy values ​​of the HFCT frequency domain signal and the UHF frequency domain signal.

13. An electronic device comprising a storage medium and a processor; the storage medium is used to store instructions; characterized in that: The processor is used to operate according to the instructions to execute the optoelectronic cooperative detection method described in any one of claims 1 to 7.

Images