181 results about "Wavelet basis functions" patented technology

The invention relates to the technical field of power supply or power distribution circuit systems, in particular to a photovoltaic module fault monitoring system and method, and the system comprises an acquisition module, a power supply dynamic compensation module, a control optimization module, a power supply module and a digital twin module. The acquisition module acquires multi-source data through the infrared thermal imaging sensor, the electroluminescent detection unit and the current and voltage characteristic curve acquisition module, the power supply dynamic compensation module dynamically adjusts wavelet basis function parameters based on an improved whale optimization algorithm, and the power supply module fuses hot spot distribution, current and voltage abnormity and aging trend data. And driving the dynamic adjustment of the protection threshold. And the digital twin module synchronizes real and virtual system data through transfer learning, rehearses a fault path to generate a maintenance instruction and feeds back the maintenance instruction to an optimization prediction model, so that a monitoring, protection and self-optimization closed-loop system is formed, and the fault diagnosis precision and the system reliability in a complex environment are improved.

The invention provides a distribution line fault waveform denoising analysis method based on an improved wavelet threshold function and computer equipment, and relates to the technical field of power system fault detection and signal processing. The method comprises the following steps: S1, obtaining a fault waveform of a distribution line through actual measurement or analogue simulation, and converting the fault waveform into a fault signal; s2, through denoising effect comparison, selecting an applicable wavelet basis function and a decomposition layer number, and carrying out wavelet transformation to decompose a fault signal; s3, carrying out wavelet decomposition coefficient threshold processing on the fault signal by adopting a self-adaptive adjustment mechanism of a threshold and an improved threshold function; and S4, performing discrete wavelet inverse transformation on the wavelet decomposition coefficient subjected to threshold processing to reconstruct a signal so as to obtain a denoised fault signal. According to the method, through the improved threshold function and the multi-scale analysis technology, the fault waveform denoising effect can be remarkably improved, the accuracy and the real-time performance of fault detection are ensured, and therefore the reliability and the safety of a distribution line are improved.

The invention provides a civil construction monitoring intelligent sensor information detection method and system under signal mismatch, and the method comprises the steps: carrying out the time-frequency analysis of temperature and strain fundamental frequency components, selecting a wavelet basis function adaptive to the concrete setting and strength increasing process, carrying out the self-adaptive threshold processing of a wavelet coefficient, removing high-frequency noise, and carrying out the detection of the temperature and strain fundamental frequency components. Low-frequency signal characteristics reflecting concrete strength increase are reserved; performing feature extraction on the denoised temperature and strain signals by adopting a singular value decomposition algorithm, detecting internal defects of the concrete through abrupt change of a singular value spectrum, and if crack and hole defects exist, causing strain signal abrupt change by stress concentration; if it is detected that defects exist in the concrete, that is, spatial heterogeneity of temperature and stress distribution exists, temperature and strain monitoring data of multi-point arrangement and a defect detection result serve as boundary conditions and constraints, and a temperature field and a stress field in the whole concrete structure are obtained through numerical simulation.

The invention relates to the technical field of laser spectrum detection, in particular to an LIBS (Laser-induced Breakdown Spectroscopy) spectrum noise reduction method, system and equipment based on adaptive threshold wavelet transform and a storage medium. Acquiring an original spectral signal of the laser-induced breakdown spectroscopy; performing five-layer multi-layer wavelet decomposition on the original spectral signal by adopting a db4 wavelet basis function to obtain a high-frequency coefficient and a low-frequency coefficient of each layer; calculating a noise intensity standard deviation based on the detail coefficient of the highest decomposition layer; dynamically determining the optimal value of the regulation factor through a double-layer optimization strategy combining a grid search method and a golden section iterative optimization method; constructing an adaptive threshold value based on the noise intensity standard deviation and the adjustment factor; carrying out threshold value processing on the high-frequency coefficient by adopting a self-adaptive threshold value; and performing wavelet reconstruction on the processed high-frequency coefficient and low-frequency coefficient, and outputting a denoised spectral signal. While the LIBS spectral signal-to-noise ratio is remarkably improved, the spectral feature form is completely reserved, and reliable technical support is provided for laser-induced breakdown spectroscopy detection in a complex industrial environment.

The invention discloses an ancient textile image restoration system based on artificial intelligence. The system comprises a multi-source image acquisition module, a damaged area detection module, a pattern generation module, a color restoration module, a texture synthesis module and a multi-scale fusion module. The system introduces a wavelet guidance-frequency domain attention mechanism and a rotation invariant Haar wavelet basis function to realize accurate identification and classification of a damaged area; a saliency-guided wavelet decomposition control and self-adaptive threshold denoising method is combined, so that the perception capability of slant textures and edge details is improved; the texture synthesis module constructs a hierarchical modeling strategy fusing Gram style loss, Wasserstein style loss and a total variation regular term, and realizes generation of high-quality textures with unified styles and smooth edges; the system can be widely applied to cultural relic digital repair and display scenes.

The invention discloses a converter transformer valve side bushing leakage current data preprocessing method based on improved wavelet transform, and relates to the technical field of insulation monitoring of transformer bushing equipment, and the method comprises the steps: obtaining transformer bushing leakage current data, and setting a state space, an action space and a reward function of reinforcement learning; selecting a wavelet basis function, and performing wavelet decomposition on the obtained leakage current data of the transformer bushing; and calculating the energy of each scale of the wavelet coefficient, and judging the energy threshold of each scale. According to the converter transformer valve side bushing leakage current data preprocessing method based on improved wavelet transformation, wavelet transformation is used when transformer bushing leakage current data is preprocessed, the number of decomposition layers is improved, the optimal number of wavelet decomposition layers is objectively selected by using the advantage of reinforcement learning autonomous decision, and the reliability of the transformer bushing leakage current data is improved. And multi-resolution frequency spectrum information of the signal is provided, noise in the original signal is suppressed, and leakage current data of the transformer bushing are efficiently processed.

The invention relates to a GIS partial discharge optical detection method and device, and a medium. The method comprises the following steps: collecting a GIS partial discharge optical signal through a light guide rod, and carrying out the preprocessing of the GIS partial discharge optical signal; self-adaptive wavelet packet decomposition is carried out on the preprocessed signals, noise signals are separated through a self-adaptive threshold value adjustment algorithm, multi-scale time-frequency characteristics are extracted from the signals after noise separation, and according to the self-adaptive wavelet packet decomposition, a wavelet basis function is selected in a self-adaptive mode according to statistical indexes of the extracted signals so as to carry out wavelet packet decomposition; and constructing a lightweight convolutional neural network model, classifying the extracted multi-scale time-frequency features, and identifying a partial discharge signal. Compared with the prior art, the method has the advantages that the anti-interference capability is high, weak partial discharge signals can be effectively extracted, and the real-time requirement is met.

The invention provides a feature extraction method for an electroacoustic background interference signal of operation power transformation equipment, which belongs to the technical field of power transformation equipment, and comprises the following steps: acquiring an electroacoustic signal, preprocessing the electroacoustic signal, and generating a controlled interference signal at the same time; and performing time-frequency analysis on the preprocessed electroacoustic signal and the controlled interference signal, and optimizing the interference signal parameter to enable the interference signal parameter to be highly similar to the electroacoustic signal. And constructing a wavelet basis function library based on the optimized controlled interference signal, and performing wavelet packet decomposition on the electroacoustic signal to obtain a plurality of frequency band sub-signals. A self-adaptive threshold model is established by using a controlled interference signal, and soft threshold denoising processing is performed on sub-signals. Time-frequency features of the denoised sub-signals and the controlled interference signals are extracted, a feature mapping relation is established, and an initial feature set is obtained; and performing nonlinear dimensionality reduction on the initial feature set by adopting principal component analysis to obtain a dimensionality-reduced feature set. And an improved support vector machine model is adopted to evaluate the importance of dimension reduction features, and an optimal feature set is selected as an electroacoustic background interference signal feature.

The invention discloses an automatic control method and system for transformer substation maintenance, operation and maintenance supervision based on data analysis, and belongs to the technical field of transformer substation maintenance, and the method comprises the steps: collecting multi-source monitoring data of a transformer substation, including voltage, current, transformer oil temperature, partial discharge signals, GIS equipment vibration frequency and insulating oil chromatographic data; performing time sequence processing on the multi-source monitoring data to generate time sequence monitoring data, performing filtering processing on power frequency noise in the time sequence monitoring data by adopting a Daubechies wavelet basis function, and performing feature extraction to obtain time sequence processing data; inputting the time sequence processing data into a pre-constructed long short-term memory network model for fault prediction to obtain an equipment fault probability prediction value; when the equipment fault probability prediction value exceeds a preset threshold value, triggering a multi-stage early warning signal and executing an automatic control operation; and according to the maintenance record data, calculating a fault recovery rate and an operation stability index, and generating a maintenance evaluation report.

The invention discloses a sampling signal noise reduction method and device based on a wavelet basis function, equipment and a medium, and belongs to the field of signal processing, and the method comprises the steps: carrying out the preprocessing of an original sampling signal after the original sampling signal is obtained, and obtaining a processing signal; performing wavelet decomposition on the processing signal to obtain a wavelet coefficient, and correcting the wavelet coefficient to obtain a correction coefficient; and performing inverse wavelet transform on the correction coefficient to obtain a noise reduction signal. According to the invention, after the original sampling signal is obtained, the preset composite power quality disturbance signal is added to the original sampling signal, and the noise reduction processing is carried out according to the wavelet coefficient of the signal combined with the noise to obtain the noise reduction signal. According to the invention, by adding the noise, high-efficiency noise suppression can be realized while key disturbance characteristics are reserved, so that the precision of the signal after noise reduction is improved; as the signal features of the original signals are reserved, a reliable preprocessing scheme can be provided for high-precision data acquisition scenes such as new energy monitoring of the power grid according to the original features subsequently.

The invention provides a multivariate time sequence prediction method and system and a medium, an input time sequence is adaptively decomposed into an approximate coefficient sequence and a detail coefficient sequence by adopting an adaptive discrete wavelet transform and inverse transform mode, and compared with the previous wavelet transform depending on a predefined wavelet basis function, the multivariate time sequence prediction method and system have the advantages that the time sequence prediction efficiency is improved; the mode is more flexible, and filtering kernels of discrete wavelet transform and inverse transform can be updated in a data driving mode in the training process according to the characteristics of the time sequence, so that the filtering kernels are more suitable for the current sequence. Wavelet transformation realized by carrying out convolution operation on a time dimension lacks extraction and modeling of correlation between global information and different variables in a multivariate time sequence; therefore, a coefficient mixing module and a wavelet domain attention channel enhancement module are provided to carry out supplementary modeling on an approximation coefficient and detail coefficient sequence obtained after wavelet transformation. The method can meet the prediction requirements of the time series in actual production such as power load.

The invention relates to the technical field of composite material structure monitoring, in particular to a composite material structure damage identification method based on acoustic emission wavelet packet energy characteristics, and the method comprises the steps: S1, obtaining acoustic emission signal data of a composite material, and carrying out the preprocessing; s2, performing wavelet packet decomposition on the denoised composite material acoustic emission signal data by using a wavelet basis function and discrete wavelet inverse transformation; s3, acquiring the processed acoustic emission signal data of the composite material, and extracting the characteristic energy of each piece of acoustic emission signal data; and S4, performing clustering analysis by using a clustering method to complete damage identification of the composite material structure. According to the method, the acoustic emission signal is used as an analysis basis, wavelet transform and k-means clustering analysis are used for accurately realizing structural damage identification and judgment of the composite material, dynamic continuous monitoring can be realized, the method is not influenced by structural complexity, and the method has wide applicability and is suitable for various composite materials.

The invention discloses a rotary machine fault diagnosis method based on PyramidNet and Transform, and relates to the field of fault diagnosis, and the method comprises the following steps: carrying out the normalization preprocessing and sliding window segmentation of an original vibration signal, and generating a time sequence data segment with a fixed length; carrying out discrete wavelet transform on the time sequence, carrying out multilayer decomposition by adopting a Daubechies 4 wavelet basis function, and converting a signal from a time domain to a frequency domain; a hybrid network model based on PyramidNet and Transform is constructed, local features are extracted by increasing the number of channels layer by layer, and channel attention and space attention optimization is carried out in combination with a CBAM module; performing time sequence modeling on the output features, and capturing a long-distance dependency relationship of a time sequence through a multi-head self-attention mechanism; according to the method, the extracted global features are classified, fault categories are output, feature extraction and fault classification are carried out by adopting an improved hybrid network architecture, the defects of a traditional method in feature extraction and global dependency modeling are overcome, and the detection precision and robustness of fault diagnosis are effectively improved.

The invention provides a fault diagnosis method and system based on multi-band multi-scale fuzzy entropy fusion for a traction rectifier with the highest fault rate in an electric locomotive traction transmission system. The method comprises the following steps: firstly, on the basis of an optimal wavelet basis function, decomposing fault signals under different working conditions and different operation modes by a wavelet packet to obtain a series of optimal frequency band information; secondly, performing coarse graining processing on the sequence of each frequency band, and calculating a multi-scale fuzzy entropy; and finally, solving the energy value of the multi-scale fuzzy entropy of each frequency band, and taking the energy value as a fault feature vector. The multiband fuzzy entropy feature obtained based on the optimal wavelet basis function has certain robustness to noise, and the fault diagnosis rate can be further improved through the proposed multi-information fusion algorithm. Compared with other methods, the method has the advantages of higher diagnostic rate and stronger robustness.

The invention discloses a transformer bushing insulation resistance calculation method under electromagnetic interference based on a Wav-KAN algorithm, and relates to the technical field of transformer bushing insulation resistance calculation. The method comprises the following steps: S1, carrying out normalization processing on a measured value of the leakage current of the transformer bushing; s2, selecting a proper wavelet basis function and a proper number of decomposition layers, and extracting detail coefficients of each layer in wavelet coefficients to construct a detail coefficient matrix as a filtering input vector; s3, establishing a KAN filtering model, and obtaining the leakage current value of the transformer bushing after the induced current is filtered; and S4, constructing an empirical calculation model of the transformer bushing capacitance. According to the method for calculating the insulation resistance of the transformer bushing under the electromagnetic interference based on the Wav-KAN algorithm, when an empirical model of a transformer bushing capacitor is constructed, influences of environment temperature, humidity and the aging degree of the transformer bushing are considered, and an induced current part in a leakage current measurement value of the transformer bushing is filtered out; according to the method, the insulation resistance of the transformer bushing can be calculated more accurately.

The invention discloses a meteorological prediction data compression storage optimization method, which belongs to the technical field of meteorological data processing, and comprises the following steps: obtaining preprocessed meteorological prediction data; performing three-dimensional wavelet decomposition on the preprocessed meteorological prediction data by using an orthogonal wavelet basis function to obtain a tensor; performing high-order tensor decomposition on the tensor to obtain a core tensor and a plurality of modal feature matrixes; regularization constraint dynamic adjustment and sparse processing are carried out on the rank of the core tensor, dimension reduction processing is carried out on the multiple modal feature matrixes, and the core tensor with the reduced rank and the multiple modal feature matrixes with the reduced storage scale are obtained and entropy coding and quantization processing are carried out on the core tensor and the multiple modal feature matrixes; obtaining the core tensor subjected to entropy coding and quantization processing and the compressed representation of a plurality of modal feature matrixes; and dynamically calibrating the storage precision and the information loss of the compression representation of the core tensor and the plurality of modal feature matrixes after entropy coding and quantization processing by using variational inference to complete the compression storage optimization of the meteorological prediction data.

The invention relates to an electrochemical impedance spectroscopy on-line measurement method and device, electronic equipment and a storage medium, and the electrochemical impedance spectroscopy on-line measurement method can collect time domain signals of a lithium battery under the excitation of a large-current pulse, such as voltage signals and current signals of the lithium battery in a large-current pulse charging state. During large-current pulse charging, a to-be-measured curve based on a time domain signal is converted into frequency domain information with the deviation of an electrochemical station reference curve smaller than a preset deviation through wavelet transform, impedance information is determined according to parameter information of a wavelet basis function in the conversion process, and an electrochemical impedance spectrum of the lithium battery is determined according to all the impedance information. Due to the fact that time-frequency analysis of the lithium battery under large-current pulse excitation can be completed, large-current pulse charging is achieved, and meanwhile online electrochemical impedance spectroscopy measurement is conducted on the lithium battery.

The invention relates to the field of communication signal processing, in particular to an air defense and disaster prevention early warning alarm real-time control system based on Beidou third-generation communication, which adopts a Daubechies wavelet family to perform five-layer discrete wavelet decomposition and decomposes the total delay of satellite signals into different scale coefficients. By accurately controlling the boundary scale, the system can effectively separate the ionosphere error from the troposphere error. And by inserting a zero value between filter coefficients, information loss caused by down-sampling operation is avoided. And aiming at different atmospheric error characteristics, the system adaptively selects an optimal wavelet basis function. A stable correction effect is kept under extreme weather conditions, and an efficient and practical air defense and disaster prevention real-time early warning control method is constructed.

The invention relates to the technical field of signal processing, and discloses a harbor equipment vibration signal processing method, which comprises the following steps: constructing a comprehensive function, and calculating a harbor equipment vibration signal based on the characteristics of a frequency scale, a second wavelet basis function and a threshold value; the concentration ratio of energy distribution, the calculation complexity of second wavelet basis functions under the frequency scale, the orthogonal value between the second wavelet basis functions under the frequency scale, the sparse value of second wavelet coefficients under the frequency scale and the signal-to-noise ratio of time domain signals reconstructed after threshold processing are comprehensively considered. The selection of the optimized frequency scale, the optimized second wavelet basis function and the optimized threshold is realized. The innovative method gets rid of the limitation of a single or optimized algorithm, fixed parameter setting or predefined rules in the prior art, and significantly improves the precision and robustness of low-frequency vibration signal processing.

The invention relates to a fault information method and device, computer equipment, a storage medium and a program product. The method comprises the following steps: acquiring fault traveling wave data of a measurement point in a direct-current power transmission system in a target time period; constructing a wavelet basis function based on the fault traveling wave data and the center frequency of the fault traveling wave data; based on a wavelet basis function, performing wavelet transformation on the fault traveling wave data to obtain fault traveling wave arrival time data corresponding to the fault traveling wave data; and based on the fault traveling wave arrival time data and the wave velocity of the fault traveling wave data, determining the fault position of the fault in the DC power transmission system. By adopting the method, the accurate positioning of the fault position can be realized.

The invention provides a CNN-based power measuring instrument short-circuit fault automatic diagnosis method, and relates to the technical field of fault diagnosis, and the method comprises the steps: presetting an acquisition period and duration, collecting and preprocessing the operation data of a power measuring instrument in real time, determining an optimal decomposition layer number based on information entropy, and dynamically selecting an optimal wavelet basis function. Carrying out wavelet packet decomposition on the preprocessed data, calculating and comparing the energy and variance of each offspring coefficient, selecting the offspring coefficient containing fault features to construct a feature vector, segmenting the feature vector into sub-feature vectors and converting the sub-feature vectors into a two-dimensional matrix, carrying out normalization processing and then dividing the two-dimensional matrix into a training set and a test set, constructing an automatic diagnosis model by combining CNN and LSTM, and introducing an attention mechanism. A sparrow search algorithm and an Adam optimization algorithm are used for optimizing model parameters, model performance is evaluated through a test set, a diagnosis result is analyzed, and accurate diagnosis of faults of the power measuring instrument is achieved. According to the invention, the accuracy and real-time performance of fault diagnosis of the power measuring instrument can be improved.

The invention discloses a natural gas pipeline leakage detection method based on novel wavelet basis transformation and singular value decomposition in a two-dimensional convolutional neural network. Firstly, a sound signal collected by a sound wave sensor is converted into a digital signal; secondly, in the data preprocessing stage, singular value decomposition is carried out on the digital signals to effectively eliminate background noise interference, and then batch normalization is carried out on the processed data; then, converting the one-dimensional time sequence signal into a two-dimensional time-frequency image by adopting a self-defined Morlet wavelet basis function; and finally, based on the time-frequency images, constructing and training a 2D-CNN model for fault classification, and presenting a diagnosis result through a confusion matrix and a comparison graph. According to the method, 97.55% of fault recognition accuracy is obtained in a public data set, and compared with other competitive methods, the method shows more excellent noise robustness and classification performance, and has higher accuracy and wide application prospects in pipeline leakage diagnosis in a complex noise environment.

The invention discloses a photovoltaic access power distribution network fault diagnosis method based on fault identification, and particularly relates to the technical field of power grid fault diagnosis, and the method comprises the steps: synchronously obtaining multi-point electrical quantity monitoring data, photovoltaic system inverter operation data and environment data of a power distribution network side, and carrying out the abnormality elimination and delay compensation preprocessing; based on the switching frequency of the photovoltaic inverter and the line parameters of the power distribution network, adaptively selecting a wavelet basis function and a decomposition scale, and extracting a fusion fault feature vector; inputting the feature vectors into a two-channel hybrid neural network model for intelligent diagnosis, and outputting fault section positioning, type classification, severity level and occurrence time information; and finally generating a fault processing instruction according to the diagnosis result. According to the method, the problems of low diagnosis precision, slow response and the like caused by single data source, poor feature extraction self-adaption and simple model structure of the existing method are effectively solved, the accuracy and reliability of complex fault recognition are remarkably improved, and closed-loop automation of fault diagnosis and processing is realized.

The invention provides a time-varying parameter model identification method based on beta wavelet basis function expansion. As shown in the flow in figure 1, the method comprises the following steps: firstly, establishing a nonlinear autoregression time-varying parameter model by using a non-stationary time-varying signal, and determining the order of the model by using an FPE order determination criterion; performing linear weighted expansion on the model time-varying parameters by utilizing a first-order beta wavelet basis function, and converting a model time-varying parameter identification problem into a time-invariant parameter estimation and model effective item selection problem, namely obtaining a beta wavelet expansion time-invariant parameter model; selecting effective items of the model by adopting a classical orthogonal forward regression algorithm, determining the number of the effective items of the model in combination with an APRESS cross validation standard, eliminating redundant items in the expansion model, estimating corresponding time-invariant parameters of the model, and establishing a sparse model structure; and finally, in combination with the obtained effective items and corresponding parameters, obtaining a sparse nonlinear autoregression model and time-varying parameters thereof through reverse solution. Compared with an existing time-varying parameter identification method based on main B-spline multi-wavelet basis function expansion, the time complexity of the identification process can be effectively reduced, the identification precision of a sparse model is improved, and a new thought and a new calculation framework are provided for identification analysis of nonlinear time-varying parameter signals.

The invention discloses a separation overload and impact signal identification method and system based on wavelet transform, and belongs to the technical field of mechanical engineering and signal processing.The method comprises the steps that S1, separation data are collected and preprocessed, and the separation data comprise separation acceleration data; s2, decomposing and separating the acceleration data through discrete wavelet transform to obtain a detail coefficient and an approximation coefficient; s3, reconstructing a high-frequency impact signal and a low-frequency overload signal based on the detail coefficient and the approximation coefficient, and obtaining an impact response positive spectrum and a negative spectrum; s4, setting different wavelet basis functions and decomposition layers, repeating the step S2 and the step S3, and separating impact and overload data through multi-objective optimization; and S5, according to the optimized separation impact and overload data, an environment test condition or a product structure strength design index is formulated. According to the method, the problems that complex trend terms cannot be accurately identified and validity criteria are lacked in the prior art are solved, and the signal separation precision and the engineering application reliability are remarkably improved.

The invention discloses an intelligent valve terminal monitoring management system of a hydraulic station, which relates to the technical field of industrial automation control and comprises a data acquisition module, a feature extraction module, a time-frequency domain combined diagnosis module, a fault diagnosis decision module, an alarm module, a remote monitoring module, a data storage module and a system control module. The method has the advantages that the adaptive wavelet packet decomposition technology is adopted to perform multi-band feature extraction on the operating parameters of the hydraulic station valve terminal, and the signal local energy entropy is combined to dynamically select the optimal wavelet basis function and the decomposition layer number, so that sensitive band features corresponding to faults such as valve element abrasion and valve internal leakage can be accurately identified; according to the system, through dynamic optimization of decomposition parameters and frequency band energy analysis, the false alarm rate is remarkably reduced, meanwhile, dependence on artificial experience is avoided, the system has the self-adaptive diagnosis capacity for complex working conditions, and therefore the accuracy and reliability of fault detection are improved.

The invention belongs to the technical field of transformer monitoring, and discloses a transformer voiceprint signal noise reduction and identification method and system in a complex environment, and the method comprises the steps: selecting a wavelet basis function to decompose a transformer voiceprint signal, and decomposing the transformer voiceprint signal into wavelet packet coefficient matrixes at different frequencies and time scales; inputting the obtained wavelet packet coefficient matrix into an anisotropic noise factor algorithm, and calculating a low-rank matrix and a noise covariance of the voiceprint signal of the transformer; reconstructing according to the low-rank matrix and the noise covariance for calculating the voiceprint signal of the transformer to obtain a denoised voiceprint signal of the transformer; and inputting the noise-reduced transformer voiceprint signal into a voiceprint signal identification network, and identifying the operation state of the transformer. According to the method, noise components can be effectively removed, the signal-to-noise ratio can be effectively improved, pure transformer voiceprint signals are obtained, and the identification accuracy is improved.

The invention relates to the technical field of intelligent driving, in particular to an intelligent non-pneumatic tire damage diagnosis method and system based on wavelet packet energy. Vibration signals of the intelligent non-pneumatic tire in the health state and different local damage states are obtained; the method comprises the following steps: processing an original vibration signal by adopting a wavelet signal de-noising method, selecting a proper wavelet basis function according to the characteristics of the signal and the characteristics needing to be highlighted, carrying out wavelet decomposition on the original vibration signal, and solving a wavelet coefficient of each node; calculating the energy of each node and the total energy, and solving the energy ratio of each node; and establishing a wavelet packet total energy change rate WER, comparing RES values, and judging the damage degree of the intelligent non-pneumatic tire. According to the invention, the precision and efficiency of damage identification of the intelligent non-pneumatic tire are improved, and powerful technical support is provided for application of the non-pneumatic tire in the field of intelligent driving.

The invention discloses a partial discharge signal feature extraction method and system, and the method comprises the following steps: collecting a current signal on a grounding loop cable of detected electrical equipment, and carrying out the preprocessing of the current signal; converting the preprocessed signal into a two-dimensional matrix, and performing singular value decomposition on the two-dimensional matrix to obtain a principal component; matrix reconstruction is carried out based on the principal component to generate a de-noising matrix, and the de-noising matrix is restored to a time domain signal sequence; performing discrete wavelet transform on the time domain signal sequence to obtain a multi-level approximation coefficient and a detail coefficient; the discrete wavelet transform selects a wavelet basis function from the candidate wavelet basis set based on a preset adaptive wavelet basis selection mechanism, and adaptively determines the number of wavelet decomposition layers based on the signal dominant frequency characteristics; and inputting the approximation coefficient and the detail coefficient into an inverse wavelet transform module to obtain a final partial discharge signal. According to the method, efficient, accurate and universal partial discharge signal feature extraction can be realized.

The invention provides a fault identification method for a photovoltaic energy storage power distribution system, and relates to the technical field of photovoltaic system fault identification, and the method comprises the steps: S1, setting a fault threshold standard; s2, collecting real-time voltage and current signals in the photovoltaic energy storage power distribution system by using a signal source; s3, selecting a proper wavelet basis function; s4, performing convolution operation on the collected signals and the selected wavelet basis function to obtain wavelet coefficients of the signals at different scales and positions; s5, analyzing the characteristics of the wavelet coefficient; and S6, according to the extracted features, in combination with a preset fault threshold, judging whether the system has a fault or not. Real-time voltage / current signals are obtained by means of a signal source to provide data support in the subsequent discrete wavelet transform process, the signals are decomposed into approximate coefficients and detail coefficients by means of wavelet transform, and the fault state existing in the power distribution process of the photovoltaic energy storage system is determined according to the high-frequency and low-frequency conditions of the approximate coefficients and the detail coefficients. And early detection of potential fault hidden dangers is facilitated.