112 results about "Time domain response" patented technology

The invention discloses an early fault diagnosis method for an analog circuit based on subsequence division and Transform. According to the method, an analog circuit time domain response signal is taken as input, a multi-class fault data set constructed by combining PSpice simulation and a Monte Carlo method is divided through a sliding window to generate subsequences, and then local time sequence characteristics are extracted by using depth separable convolution and an SE module and resistance and capacitance fault sensitive frequency bands are adaptively enhanced; the method comprises the following steps: firstly, position coding is carried out on a device, then time sequence information which keeps cross-subsequence with position coding is embedded through token, a Transform encoder modeling global dependency relationship is input, meanwhile, a time sequence coupling effect generated by multi-device collaborative degradation is captured, and finally, multi-class fault diagnosis is completed through a full-connection fault diagnosis module. According to the method, weak fault features and cross-time slice long-range correlation caused by early degradation can be effectively recognized, and experimental results show that the method has high precision and good engineering application value under complex working conditions.

The invention discloses a flexible riser vibration response characteristic analysis method, and relates to the technical field of ocean engineering. According to the method, a flexible riser vibration model is established based on a vibration theoretical model and a fluid control equation for vibration analysis, a theoretical time domain response curve of the flexible riser is obtained through MATLAB calculation, and then a flexible riser three-dimensional simulation model is established in an ANSYS Workbench integrated simulation platform. According to the method, a flexible riser three-dimensional simulation model is constructed, material constitutive parameters, boundary conditions and load application of the flexible riser three-dimensional simulation model are configured, then simulation is performed in an ANSYS Workbench integrated simulation platform by using the flexible riser three-dimensional simulation model, bidirectional fluid-solid coupling analysis is performed by coupling a Fluent flow field system and a Transient Stratum module, the radial displacement time history of the flexible riser under a preset working condition is obtained, and the radial displacement time history of the flexible riser under the preset working condition is calculated. And extracting resonance characteristics of the flexible riser. According to the method, the vibration response characteristics of the deep-sea flexible riser under the influence of internal and external fluids in the service process are accurately obtained, and a foundation is laid for guiding the structural stability of a deep-sea operation system.

The invention discloses a cable defect early warning method and device, terminal equipment and a storage medium, and belongs to the technical field of cable defect early warning, and the method comprises the steps: carrying out the frequency sweeping test of an equivalent circuit model, generating a reflection coefficient spectrum, separating a low-frequency component from the reflection coefficient spectrum, and taking the low-frequency component as a head-end reflection coefficient, through combination of the head end reflection coefficient, the internal resistance of the test equipment and the cable impedance, equivalent impedance at the joint of the test fixture and the head end of the cable is obtained through quantification, and an original reflection coefficient spectrum is corrected according to the equivalent impedance, so that impedance mismatch of the test fixture in the test process is eliminated. The corrected reflection coefficient spectrum can reflect the impedance of the cable body more accurately, so that the subsequently obtained time domain response can reflect the defect condition of the cable body more truly, and the accuracy of cable defect early warning is improved. The problem that the accuracy of cable defect early warning is low due to the fact that the original reflection coefficient spectrum cannot be corrected in the prior art can be solved.

The invention relates to the technical field of numerical simulation ship response, in particular to a ship hydrodynamic response numerical simulation method and system considering the effects of a complex wave field and an automatic mooring system. Firstly, ship radiation potential and hydrodynamic coefficients are obtained based on a three-dimensional potential flow theory and a boundary element method, and wave field information at a berth is obtained in combination with a Boussinesq wave theory; the time domain wave force is solved through the Haskind-Relation theory, and an automatic mooring numerical model integrated with a PD controller is established to calculate the automatic mooring force and torque; and finally, constructing a ship six-degree-of-freedom time domain motion equation based on the data, and solving by adopting a four-order Runge-Kutta method to obtain a time domain response result. The hybrid Boussinesq-Panel technology is adopted, the wave disturbance evaluation accuracy is improved, the blank that existing simulation does not consider an automatic mooring system sufficiently is filled up, arrangement, parameters and control strategies of the automatic mooring device can be flexibly adjusted and secondarily developed, applicability and flexibility are high, and the method is suitable for large-scale popularization and application. And reliable decision support can be provided for procurement and deployment of automatic mooring equipment of a port.

The invention relates to the technical field of electromagnetic scattering, in particular to a frequency domain response calculation method and device of an electromagnetic field, equipment and a storage medium. Performing recursive transformation on the time domain basic system equation according to the discrete time domain set and a backward Euler method to obtain a time domain transformation equation and an algebraic matrix equation; carrying out back substitution solving operation on the algebraic matrix equation according to a time domain stepping method and a time domain transformation equation; performing full-time-domain response calculation on the time-domain finite element solution based on a time-domain finite element method to obtain a time-domain base solution; calculating the time domain base solution according to a preset linear superposition principle to obtain a frequency domain response; a continuous problem is dispersed through a backward Euler method, rapid back substitution solution is carried out after factorization for one time, and redundant calculation is reduced; based on a linear superposition principle, phase weighting is carried out to synthesize a time domain base solution, frequency domain response of any frequency is rapidly obtained, frequency-by-frequency repeated calculation is avoided, efficiency is improved, and the method is suitable for broadband high-precision electromagnetic field analysis and has remarkable application value.

The invention discloses an intelligent temperature control production system for an environment-friendly asphalt cold patch additive, and relates to the technical field of asphalt cold patch additive production, and the system comprises a controller initial modeling module which is used for recording the currently set proportional-integral-differential controller parameters, and constructing a reference control feature vector used for representing the initial response behavior of a controller; and the thermal load response identification module is used for applying micro-amplitude step type temperature disturbance to the to-be-heated environment-friendly asphalt cold patch additive and extracting a thermal load characteristic vector representing the thermal response characteristic of the additive. According to the method, intelligent matching and full-time-domain response evaluation are realized by constructing control and thermal load feature vectors and combining cross-correlation and grey correlation analysis; a sliding spectrum entropy and self-adaptive parameter correction mechanism is introduced, a closed-loop regulation system is constructed, the suitability, stability and additive dispersing performance of a temperature control system are effectively improved, and the problems of control lag and fluctuation are solved.

The invention discloses a distribution line lightning stroke grading protection method based on geographical environment factors, and relates to the field of power system overvoltage protection and electromagnetic transient calculation, and the method comprises the following steps: S1, obtaining the real geographical environment parameters of a distribution line system; s2, performing multi-scale conductor distributed parameter modeling on the distribution line system; s3, modeling a nonlinear device of the distribution line system; s4, establishing a thunder and lightning channel model; s5, establishing a lightning arresting shielding model; s6, solving lightning stroke electromagnetic transient time domain response; step S7, lightning stroke risk comprehensive index output; step S8, lightning stroke risk grading protection; according to the invention, the output of the optimal differential protection scheme under the target protection level is realized, and a reliable theoretical basis and an effective technical path are provided for calculation and research of lightning electromagnetic transient effect of the overhead distribution line of the power system, random process evaluation of lightning activity and comprehensive protection design of line lightning.

The invention provides a dendritic pipe network thermal dynamic modeling method based on a transfer function, and belongs to the technical field of electric digital data processing. The method comprises the following steps: firstly, establishing an advection diffusion-heat loss control equation of a single pipeline, and deducing a frequency domain transfer function of the single pipeline through Laplace transformation; then combining theoretical analysis and high-precision numerical simulation to accurately calibrate and correct a turbulence temperature diffusion coefficient alpha and a temperature loss coefficient gamma, so that the physical consistency of the model is remarkably improved; the method comprises the following steps: for a dendritic pipe network topological structure, decomposing the dendritic pipe network topological structure into a plurality of independent branches according to heat user load nodes, and constructing a frequency domain expression of the return water temperature of the whole pipe network based on a flow weighting principle; and finally, obtaining a time domain response through inverse Laplace transformation. The method effectively solves the contradiction between the insufficient precision of a traditional node method and the complex calculation of a high-precision numerical method, considers both the modeling precision and the calculation efficiency, and is suitable for the real-time optimization scheduling of the heat supply pipe network in the comprehensive energy system.

A continuous time linear equalizer (CTLE) includes a first circuit path and a second circuit path. The first circuit path has a first step response. The second circuit path is in parallel with the first circuit path. The second circuit path has a second step response with a pulse response, and includes a transmission line that is configured to control a pulse width of the pulse response according to a length of the transmission line. An output signal of the CTLE is derived from an output signal of the first circuit path and an output signal of the second circuit path.

The application relates to the field of photonic device modeling, and discloses a parameterized optoelectronic joint simulation platform construction method for optoelectronic chip design, which is characterized in that, in an electronic design automation platform, a unified model framework of a photonic device is constructed based on a hardware description language, and conversion between frequency domain response and time domain response is realized in the model, including the following steps: a general VerilogA model framework is constructed based on the frequency domain response of the photonic device; a frequency-time domain numerical conversion mechanism is realized in the model; and for the photonic device with dispersion characteristics, a parameterized time domain model is constructed based on a finite impulse response. The application can directly embed the photonic device model into an electronic circuit simulation environment, co-simulate the electronic device, support time-frequency domain analysis of the cascade structure and the loop structure, thereby avoiding the complicated steps of separate simulation by relying on external simulation tools in the process of optoelectronic chip design, and further improving the design efficiency and iteration speed of the chip.

The invention discloses a photoelectric pod damping control method and device based on a simulation environment, and relates to the technical field of simulation. The method comprises the following steps: constructing a three-dimensional simulation environment and each simulation period, based on a virtual camera imaging principle, obtaining a target miss distance, mapping the target miss distance into an angle tracking error of a pod control axis, independently designing a proportional-differential controller for the pod control axis, obtaining a continuous time control law, and converting the continuous time control law into discrete time for representation to obtain a discrete control quantity. Setting initial proportional gain and damping gain in a three-dimensional simulation environment, analyzing a time domain response curve of target miss distance based on discrete control quantity, iteratively adjusting parameters until preset performance indexes are met, enabling the time domain response of the miss distance to be optimal, and taking the corresponding proportional gain and damping gain at the moment as a parameter set for photoelectric pod control. A real object platform is replaced by a simulation environment, and the problems that a traditional damping parameter setting method is high in cost and low in efficiency are solved.

The invention provides a self-calibration method and system for a VNA port extension test system and a test system, and the method comprises the steps: recalibration is carried out, so that a path between a VNA port and a corresponding switch matrix output port is in a disconnected state; the port transmits a signal and measures anti-radio frequency domain data in a disconnection state and time domain response of the anti-radio frequency domain data; time domain data of directivity errors, time domain data of reflection tracking errors and corresponding frequency domain responses are obtained through a first gating gate and a second gating gate; the drift distance of a reflection error item is calculated, and the directivity error and the reflection tracking error of each port are updated; performing S parameter measurement on the DUT to be measured; the drift distance of the ET is obtained according to the obtained drift distance of the reflection error term, and the transmission error term is updated based on the drift distance of the ET; and correcting the measurement data of the current DUT to be measured to obtain an accurate S parameter. According to the invention, a self-calibration function without interruption of production can be realized, and the test efficiency is improved.

The application discloses a kind of active suspension system model parameter adaptive calibration test bench test method and system, belong to vehicle active suspension test technical field, sensitive system parameters are filtered out by sensitivity analysis function, then sensitive system parameters are identified and calibrated, greatly reduce the amount of calculation in calibration process, improve the test implementation efficiency;Through time delay boundary calculation, the time delay feedback coefficient and time delay are optimized, the optimal time delay feedback coefficient and optimal time delay are obtained, and through adaptive adjustment, time delay compensation calibration is carried out using Smith prediction compensation model, which significantly improves the adaptive ability and compensation accuracy of time-varying time delay;In addition, standard test signals are applied to the target active suspension test bench test system, and time domain response data are collected to determine the tolerance according to the time domain response data to complete the parameter adaptive calibration of the active suspension system dynamics model.

The invention belongs to the field of mechanical engineering, and particularly relates to a method for calculating the dynamic stiffness of a new energy reducer shell bearing seat. The method aims to solve the problem of low dynamic stiffness prediction precision caused by neglecting manufacturing residual stress and multi-physics field coupling effect in traditional simulation. A refined finite element model containing a high-density mixed grid and material nonlinear characteristics is constructed, a die-casting residual stress field based on neural network prediction is integrated, multi-source dynamic loads such as gear alternating torque, electromagnetic pulse power and road surface excitation are coupled, nonlinear transient dynamics solution is executed, and a die-casting residual stress field is obtained. And obtaining time domain response data of the bearing seat node. In addition, a process-structure-performance database and a rapid prediction model are established, lightweight design closed-loop optimization and digital twinning online monitoring are supported, simulation accuracy and engineering application efficiency are improved, and the method is suitable for dynamic performance analysis and service life management of the new energy automobile speed reducer.

The invention provides a multi-mode dynamic strain monitoring method and system based on blade tip acceleration, and belongs to the technical field of aero-engines, and the method comprises the steps: recording a vibration arrival time sequence of a blade in a multi-mode vibration state, building a vibration acceleration calculation model, calculating the vibration acceleration of the blade tip, and obtaining an undersampling blade tip vibration acceleration signal; based on the signal, establishing a blade multi-modal vibration parameter sparse identification model, reconstructing an acceleration response, obtaining a blade multi-modal vibration acceleration parameter, and calculating a blade tip vibration acceleration full-time domain response; establishing a finite element model of the rotor blade, obtaining a multi-modal acceleration and a strain modal shape of the blade, and constructing a dynamic strain conversion relation from the vibration acceleration of the blade tip to any point of the blade; and calculating and monitoring any inching strain of the blade based on the full-time-domain response and conversion relation of the blade tip vibration acceleration. According to the invention, the dynamic strain change of the blade under multi-mode vibration can be accurately captured, and the monitoring accuracy and real-time performance are improved.

The application discloses a kind of flexible direct current transmission line fault transient electrical quantity determination methods, comprising: according to the circuit parameter of MMC converter station, construct MMC equivalent circuit when inter-pole short circuit;According to the transmission line parameter obtained, establish the equivalent model of two-port of direct current transmission line under complex frequency domain;According to the equivalent circuit of MMC when inter-pole short circuit and the equivalent model of two-port of direct current transmission line, obtain the expression of direct current fault transient under complex frequency domain;The expression of direct current fault transient under complex frequency domain is carried out Laplace transformation to obtain time domain response, the whole trend of transient process after fault can be given more accurately by the application.The calculation process is simple, avoids the complicated modeling simulation process in traditional simulation method.Meanwhile, it can well reflect the occurrence wave process when overhead line fails.The method can accurately express the overall development trend of the fault current flowing through the protection installation before the converter station is locked after the fault occurs, and has a positive significance for the fault current suppression and protection setting design of MMC-HVDC system.

The present application relates to the technical field of material dynamic mechanical property testing, and discloses a self-adaptive Hopkinson bar experimental parameter real-time regulation method and system, which comprises the following steps: obtaining incident wave signals, reflected wave signals and transmitted wave signals; denoising the incident wave signals to obtain denoised waveforms; loading the denoised waveforms into a finite element model to perform transient dynamics calculation to obtain a simulated response set, and combining a dispersion equation model analysis to obtain a geometric dispersion delay spectrum; reconstructing a simulated distorted waveform from the geometric dispersion delay spectrum and calculating a constitutive matrix; loading the constitutive matrix into the finite element model to obtain a time-domain response sequence, combining a regression model prediction to obtain a comprehensive distortion prediction, and predicting a preliminary compensation amount through a neural network model; calculating an initial strain rate, correcting the preliminary compensation amount to obtain a corrected compensation amount, using the corrected compensation amount to perform distortion compensation, calculating a feedback strain rate, combining a constant strain rate to verify a strain rate deviation, and realizing a constant sample strain rate. The present method can realize constant sample strain rate.

This application provides a multimodal dynamic strain monitoring method and system based on blade tip acceleration, belonging to the field of aero-engine technology. The method includes recording the vibration arrival time series under multimodal vibration states of the blade, establishing a vibration acceleration calculation model, calculating the blade tip vibration acceleration, and acquiring an undersampled blade tip vibration acceleration signal. Based on this signal, a sparse identification model of the blade's multimodal vibration parameters is established, the acceleration response is reconstructed, the blade's multimodal vibration acceleration parameters are obtained, and the full-time domain response of the blade tip vibration acceleration is calculated. A finite element model of the rotor blade is established to obtain the blade's multimodal acceleration and strain mode shapes, and the transformation relationship between blade tip vibration acceleration and dynamic strain at any point on the blade is constructed. Based on the full-time domain response and transformation relationship of the blade tip vibration acceleration, the dynamic strain at any point on the blade is calculated and monitored. This application can accurately capture the dynamic strain changes under multimodal blade vibration, improving monitoring accuracy and real-time performance.

The invention belongs to the technical field of material characteristic analysis, and particularly relates to a prefabricated part in-mold compactness monitoring method and system. The method comprises the following steps: applying impact to a measuring point outside a mold, collecting elastic wave time domain response signals of adjacent sensors, and constructing self-correlation attenuation-Gaussian composite window cut-off signals; fourier transform is carried out on the truncated signal, a dimension-entropy weight composite spectrum is generated after frequency sub-bands are divided, and an inherent frequency peak is positioned; calculating a quality factor of the inherent frequency peak, extracting harmonic frequency peak energy to form a multi-scale spectrum peak energy distribution vector, and calculating Shannon entropy; matching a temperature-quality factor coupling model from a preset model library by using Shannon entropy, and correcting a quality factor in combination with an in-mold environment temperature; and inputting the inherent frequency peak, the temperature compensation quality factor and the energy distribution vector into a nonlinear mapping model, and outputting the in-mold compactness of the prefabricated part. According to the method, high-precision and reliable quantitative evaluation of the in-mold compactness of the prefabricated part is realized.

The application provides a vibration test load spectrum compiling method and device, and the method comprises the following steps: acquiring vibration acceleration time domain load, dynamic stress time domain response and vehicle running speed of the actual running condition of a hanging component; dividing the vehicle running speed data into several speed intervals according to the running speed range of the vehicle; obtaining vibration acceleration power spectrum and dynamic stress power spectrum through Fourier transform; performing goodness-of-fit test on the obtained vibration acceleration power spectrum to confirm the distribution of the vibration acceleration power spectrum; synthesizing the vibration acceleration power spectrum under all speed levels into vibration acceleration function test load spectrum under different confidence levels according to the proportion of each speed level in the service period of the vehicle; and compiling the vibration acceleration function test load spectrum under different confidence levels into corresponding vibration acceleration fatigue test load spectrum according to the vibration acceleration function test load spectrum, the service period and the target bench vibration test time.

The invention provides an aluminum alloy homogenizing furnace abnormal state detection method based on data driving, which comprises the following steps of: fitting heating section data and natural gas consumption data of an aluminum alloy homogenizing furnace in a normal state by using a time domain response curve of a second-order control system under a step signal in advance to obtain a corresponding standard control curve; acquiring natural gas consumption data and electric energy consumption data of the to-be-detected aluminum alloy homogenizing furnace in each production process; calculating an accumulative error between the heating section data and a preset heating electric energy standard control curve through a fixed sliding window, calculating an accumulative error between the natural gas consumption data and a preset natural gas standard control curve, and preliminarily judging that the data is abnormal when the accumulative error corresponds to a corresponding accumulative error threshold value; and re-checking the abnormal data by adopting an isolated forest anomaly detection model.

This paper presents a model-based dynamic analysis and design method for conical-cylindrical shells. To address the problem of low computational efficiency in structural dynamics analysis and design optimization caused by the extremely high degree of freedom in traditional finite element methods (FEM) models when dealing with conical-cylindrical shell structures of submarines, the method divides the conical-cylindrical shell structure of the submarine into two substructures and models them using the FEM. The fixed interface principal modes and constraint modes of the substructures are solved, and these are combined into a first coordinate transformation matrix condensed model, resulting in a condensed model. The two condensed models are integrated, and a second coordinate transformation matrix is ​​obtained using the interface compatibility conditions between the substructures. This second coordinate transformation matrix is ​​then used to process the integrated model, yielding a condensed model of the conical-cylindrical shell structure. The frequency response curves and time-domain response curves of the condensed model of the conical-cylindrical shell in modal space are calculated, and then transformed to physical space to obtain the frequency response curves and time-domain response curves in physical space.

The application discloses a simulation method and device for transmission characteristics of an automobile power system. According to the structure of the power system and the physical process of power system transmission, an initial transfer function of the power system torque and rotating speed is determined. A pulse torque is applied to the input end of the power system, the output shaft rotating speed change is obtained, the time domain response result of the system is determined, the parameters of the initial transfer function are determined, the transfer function is determined, and the power system transmission characteristic model is established. The torque demand of the power system to be measured is input into the power system transmission characteristic model, and the simulation result of the rotating speed change is obtained. The application can simulate and evaluate the performance of the vehicle power transmission system, and solves the problem that the prior art cannot simulate and evaluate the drivability in the early development stage.

This invention relates to the field of health management technology, specifically to a health management physical examination big data platform. The system includes a fluctuation start point localization module, a rhythm structure adjustment module, a trend trigger identification module, a vital sign linkage extraction module, and an intervention task sequencing module. In this invention, the fluctuation start point is located by jointly locating the direction of resistance change and abrupt shifts in offset. The sampling interval is dynamically adjusted and the fluctuation sequence is rearranged. The trend continuation path is identified using boundary deviation states, enhancing the coherence and stability of trend identification. The response start point and continuation region are extracted by combining directional consistency items in respiratory vital signs, ensuring the completeness of time-domain response coverage. Furthermore, a priority calling order is constructed based on the distribution density, frequency of occurrence, and duration of vital signs on the time axis. This achieves accurate identification of trend start points, orderly adjustment of rhythm structures, and optimization of intervention task timing in the dynamic linkage process of multiple vital signs, improving response efficiency and control accuracy in the evolution of health status.

The application provides a kind of branch pipe network thermal dynamic modeling method based on transfer function, belongs to the technical field of electric digital data processing.The application first establishes the advection diffusion-heat loss control equation of single pipeline, and deduces the single pipe frequency domain transfer function through Laplace transform;Then, combined with theoretical analysis and high-precision numerical simulation, the turbulent temperature diffusion coefficient α and temperature loss coefficient γ are accurately calibrated and corrected, which significantly improves the physical consistency of the model;For the topology structure of branch pipe network, it is decomposed into multiple independent branches according to the heat user load node, and the frequency domain expression of the overall pipe network return water temperature is constructed based on the flow weighting principle;Finally, the time domain response is obtained by inverse Laplace transform.The application effectively solves the contradiction between the insufficient accuracy of traditional node method and the complexity of high-precision numerical method, balances the modeling accuracy and calculation efficiency, and is suitable for real-time optimization scheduling of heating pipe network in integrated energy system.

The invention relates to the technical field of electrochemical energy storage, and discloses a lithium ion battery health state prediction method based on impedance spectrum frequency band characteristics, and the method comprises the following steps: applying a binary current excitation signal containing a plurality of frequency components to a to-be-detected lithium ion battery, and generating the excitation signal; when the excitation signal is applied, terminal voltage time domain response of the battery is collected at the sampling rate of 1 kHz to 100 kHz, and voltage response data is generated; by applying a short-time multi-valued current excitation signal containing a specific frequency band, ohm, charge transfer and diffusion multi-electrochemical process response of the battery can be synchronously excited within a few seconds, and traditional time-consuming capacity testing and frequency domain impedance spectroscopy scanning are replaced. Therefore, the system can rapidly evaluate and screen the health state of the battery in an industrial scene, and the detection efficiency is greatly improved.

The application discloses a dynamic interference suppression method of multipath channel phase focusing and harmonic reverse phase cancellation, relates to the technical field of interference suppression, and comprises a path characteristic extraction module, which extracts sampling data of a received signal, constructs a received signal matrix, generates a pilot signal, carries out filter processing on a noise matrix, calculates a channel frequency response matrix, and extracts path characteristics by using a peak value detection method. The method can comprehensively calculate the time delay component contribution of the channel time domain response by discretizing the channel frequency response matrix through limited sampling points and combining all frequency components in the frequency bandwidth, can enhance the dynamic response capability of the channel model by introducing time-varying environmental characteristics through a dynamic path time delay function, can improve the signal characteristic correction precision through dynamic compensation of path time delay error phase rotation, and can realize the channel description process with path grouping as the core.

The application is suitable for the technical field of automobile performance evaluation, and provides a vehicle acceleration dynamic response consistency evaluation method based on time domain response characteristics, which comprises the following steps: step 1, test condition definition; step 2, data acquisition and preprocessing; and step 3, evaluation index calculation. The method is composed of three parts of test condition definition, data acquisition and preprocessing and evaluation index calculation, can objectively and accurately quantify the vehicle acceleration dynamic response consistency, effectively makes up for the lack of evaluation method in the prior art and the difficulty in realizing objective quantification, and provides reliable technical support for vehicle performance optimization and driving quality improvement.

The invention relates to a self-adaptive prediction control method and system for an LCL type active power filter, and the method comprises the following steps: introducing a self-adaptive weight, dynamically fusing a power supply current frequency domain detection component and a load current time domain detection component, and fusing frequency domain high-precision detection and time domain quick response detection through the self-adaptive weight. The limitation of a single detection mode is overcome, and the compensation precision and the response speed can be improved respectively under the steady-state and transient-state working conditions; the reference current is predicted in advance according to the digital control delay step size, an inverter voltage instruction is calculated in a reverse recursive mode according to the reference current, the inverter voltage instruction is corrected to obtain a final instruction, and the final instruction drives a voltage source inverter to output compensation current; according to the compensation current tracking error and the load power change rate, the self-adaptive weight, the outer ring prediction step length and the self-adaptive virtual damping coefficient are dynamically adjusted, and the overall adaptability of the system to complex working conditions is enhanced.

The application discloses a high-voltage cable metal sheath loop resistance time-frequency domain dual-mode live detection method, comprising the following steps: S1. generating a multi-frequency band composite excitation signal containing a low frequency band, a medium frequency band and a high frequency band; S2. injecting the multi-frequency band composite excitation signal into a high-voltage cable metal sheath loop in operation and synchronously collecting time domain response signals and frequency domain response signals; S3. extracting time-frequency domain characteristic parameters according to the time domain response signals and the frequency domain response signals; and S4. inputting the time-frequency domain characteristic parameters into a preset defect diagnosis model to output a defect type and a defect degree of the high-voltage cable metal sheath. The application breaks through the limitation of single frequency detection, establishes the correlation between impedance-frequency and impedance-time domain characteristic curves, and significantly improves the defect recognition accuracy and positioning precision.