22 results about "Time domain response" patented technology

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.

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 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 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.

This invention discloses a method for controlling wind-induced vibration during the construction of a long-span cable-stayed bridge in mountainous areas, comprising: obtaining the average wind speed profile at the construction site; constructing a fluctuating wind speed power spectrum model and a coherence function model at the construction site; extracting the generalized transfer function and correlation reduction factor to correct the fluctuating wind speed power spectrum model and the coherence function model; constructing a power spectral density matrix based on the corrected fluctuating wind speed power spectrum model and the coherence function model at the construction site; determining the phase angle and weighting coefficient of each frequency component after decomposition and generating harmonic components and weighted superposition to generate fluctuating wind speed time history samples at various points in the main beam and bridge tower space; obtaining buffeting force load and static wind load; obtaining self-excited force load at various points in the main beam; constructing finite element models of the target bridge under different construction states; using the superposition of buffeting force load, static wind load, and self-excited force load as input load time history parameters to simulate the vibration time-domain response of the target bridge under different construction states and optimize vibration control measures.

This invention relates to the field of photovoltaic intelligent operation and maintenance technology, and discloses a method for predicting faults in distributed photovoltaic modules based on machine learning. The method includes: collecting DC voltage and current sequences of the modules, constructing a power time series through time-axis normalization, and decomposing it into a steady-state envelope component representing environmental changes and a transient disturbance component representing control actions using a filter; performing spectral analysis on the transient disturbance component, locking the maximum power point tracking oscillation frequency within the current window, extracting the intermodulation sideband energy distribution around this frequency and its harmonics, and calculating the bypass coupling index reflecting the nonlinearity of the module accordingly; constructing a prediction model including a long-time-series evolution extraction channel, a short-time-series waveform extraction channel, and an adaptive gating unit; dynamically weighting and fusing frequency domain structure information and time domain response information using the attention coefficient generated by the adaptive gating unit based on the bypass coupling index; and mapping the fused comprehensive representation to a health state probability.

The application discloses a kind of power transmission tower component abnormal vortex vibration early warning method, including obtaining power transmission tower component vibration image, calculating curve peak point, the center point of two peak points is selected as virtual measuring point;According to the relative displacement of the position where virtual measuring point is located by the longitudinal coordinate variation calculation of virtual measuring point;When relative displacement reaches variation threshold, determine that power transmission tower component appears vortex vibration, obtain time domain vortex vibration identification index;With relative displacement as time domain response, carry out frequency domain analysis, when energy amplitude is greater than threshold value, and duration is greater than time length threshold value, determine that power transmission tower component appears vortex vibration, obtain frequency domain vortex vibration identification index;According to time domain vortex vibration identification index and frequency domain vortex vibration identification index, determine the early warning level of power transmission tower component abnormal vortex vibration.No need to power off or climb operation, can be directly measured on the ground, greatly reduce field operation difficulty and safety risk, reduce the operation and maintenance cost, more easily in the patrol personnel and be applied.

The application discloses a kind of multi-terminal flexible DC transmission system fault current monitoring methods considering hybrid converter station active current limiting control.First, the equivalent model of DC line and the equivalent model of hybrid converter station in different response stages are established;Then, according to the topological structure of multi-terminal flexible DC transmission system, the spatial state equation set of the whole system is established;Solve the state space equation set, obtain the time domain response of fault current.The application realizes the accurate calculation of the fault current of multi-terminal flexible DC transmission system by fully considering the dynamic response characteristics of converter station active current limiting control, so as to realize the accurate monitoring of the fault current of multi-terminal flexible DC transmission system.

The application provides a segment positioning method and system for high-voltage cable sheath ground fault, which can be used in the technical field of cable maintenance. The method comprises: monitoring the ground circuit of the target high-voltage cable to obtain a monitoring data set of the target high-voltage cable; determining a cross-interconnected segment in the target high-voltage cable based on the monitoring data set; equivalent the circuit connection relationship of the cross-interconnected segment to a network topology structure to obtain a cross-interconnected equivalent circuit; determining a fault positioning circuit in the cross-interconnected equivalent circuit based on the real-time waveform feature fingerprint of the cross-interconnected equivalent circuit and a pre-constructed fault waveform feature fingerprint library; injecting a time-domain reflection pulse signal to the fault positioning circuit to obtain a time-domain response pulse signal of the fault positioning circuit; and performing time-domain reflection analysis on the time-domain response pulse signal to determine a ground fault positioning segment of the fault positioning circuit. The application significantly improves the accuracy of segment positioning for high-voltage cable sheath ground fault.

The application discloses a kind of grid-connected point equivalent grid impedance identification method and equipment using full-power variable-speed pumped storage, medium, it is related to new energy grid performance test technical field.The method comprises: to the voltage command of q axis or d axis of full-power variable-speed pumped storage grid-connected power electronic converter, controllable broadband disturbance signal is superimposed, so that converter includes the disturbance corresponding to controllable broadband disturbance signal in the output to the measured grid-connected point;Voltage and current time domain response data of measured grid-connected point are collected;From the voltage and current time domain response data collected, extract the voltage and current spectrum response data in preset frequency band;Based on the voltage and current spectrum response data in preset frequency band, the equivalent grid impedance of measured grid-connected point is calculated.The present application does not need complex equipment field installation process, also does not need additional development impedance identification device, improves technical economy and implementation convenience.

The application discloses a kind of reuse spacecraft sinusoidal vibration test scanning rate calculation method and system, comprising: selecting observation point on spacecraft, obtaining scanning rate and frequency domain sinusoidal vibration condition;The frequency domain sinusoidal vibration condition is converted into time domain sinusoidal vibration condition;Time history analysis is carried out to observation point, and stress time domain response is obtained;The rainflow counting is carried out to the stress time domain response, and rainflow counting result is obtained;Single fatigue damage of observation point is calculated;M fatigue damage of observation point is calculated;The scanning rate of the observation point is adjusted, and the scanning rate when single test fatigue damage is equal to M fatigue damage of the observation point is calculated;The relationship between scanning rate and spacecraft reuse frequency is obtained, for calculating the test scanning rate corresponding to any reuse frequency.The application realizes once test to check multiple flights, avoids the damage risk of multiple tests to product, and can provide support for the development of reusable spacecraft.

The application belongs to the technical field of electromagnetic transient characteristics, and particularly relates to a GIL partial discharge electromagnetic transient time domain finite element analysis method, which comprises the following steps: constructing a three-dimensional electromagnetic field simulation model according to actual structure parameters of a gas insulated metal enclosed transmission line; setting boundary conditions of electromagnetic wave propagation according to the three-dimensional electromagnetic field simulation model; setting an oscillation type excitation source and a non-oscillation type excitation source in the three-dimensional electromagnetic field simulation model according to physical characteristics of partial discharge; performing electromagnetic transient simulation calculation by using a time domain finite element method according to the three-dimensional electromagnetic field simulation model, the boundary conditions and the excitation sources, so as to obtain electromagnetic field time domain response data of each detection point in space; extracting electromagnetic field peak intensity and spatial distribution characteristics under different excitation sources according to the electromagnetic field time domain response data, and analyzing electromagnetic transient characteristics of the two types of excitation sources.

The application discloses a thin-film type floating photovoltaic platform out-of-plane motion analysis method, device and equipment. The method comprises the following steps: constructing an overall dynamic equation of the out-of-plane motion of the photovoltaic platform based on a dynamic equation and a displacement equation of the out-of-plane motion of the thin film and the floating ring; determining a time-domain wave load of the out-of-plane motion of the photovoltaic platform; determining a time-domain mooring force in the vertical direction of each mooring cable for constraining the photovoltaic platform, and determining a vertical component of a mooring point reaction force based on the time-domain mooring force; constructing a compatibility matrix based on the displacement equation of the out-of-plane motion of the thin film and the floating ring, and constructing a coupled dynamic equation of the out-of-plane motion of the photovoltaic platform based on the overall dynamic equation, the time-domain wave load, the vertical component and the compatibility matrix by using a Lagrange multiplier method, and performing time-domain solving on the coupled dynamic equation to obtain a time-domain response of the out-of-plane motion of the photovoltaic platform. Therefore, the out-of-plane motion response of the photovoltaic platform can be accurately described.

The application discloses a thin-film type floating photovoltaic platform out-of-plane motion analysis method, device and equipment. The method comprises the following steps: constructing an overall dynamic equation of the out-of-plane motion of the photovoltaic platform based on a dynamic equation and a displacement equation of the out-of-plane motion of the thin film and the floating ring; determining a time-domain wave load of the out-of-plane motion of the photovoltaic platform; determining a time-domain mooring force in the vertical direction of each mooring cable for constraining the photovoltaic platform, and determining a vertical component of a mooring point reaction force based on the time-domain mooring force; constructing a compatibility matrix based on the displacement equation of the out-of-plane motion of the thin film and the floating ring, and constructing a coupled dynamic equation of the out-of-plane motion of the photovoltaic platform based on the overall dynamic equation, the time-domain wave load, the vertical component and the compatibility matrix by using a Lagrange multiplier method, and performing time-domain solving on the coupled dynamic equation to obtain a time-domain response of the out-of-plane motion of the photovoltaic platform. Therefore, the out-of-plane motion response of the photovoltaic platform can be accurately described.

This application discloses a method, apparatus, equipment, and medium for monitoring the interaction coupling behavior of grid-type and grid-connected converters, relating to the field of power system technology. The method includes: injecting a disturbance signal into the input signal of a target converter to determine the time-domain response of the output signal; discretizing the time-domain response to obtain data at each frequency point; the target converters include grid-type and grid-connected converters; generating state variables for each frequency point data and mapping each state variable to a preset high-dimensional observable space; generating local models for each target frequency point based on the mapping results; fusing the local models based on target weights to obtain a global model; determining the coupling relationship between the grid-type and grid-connected converters; analyzing the interaction between the grid-type and grid-connected converters based on the coupling relationship; and identifying potential unstable devices or channels based on the analysis results. This application is capable of performing interaction coupling analysis between grid-type and grid-connected converters.

The application discloses a kind of high mountain and valley site seismic time history simulation method and system, belong to geotechnical earthquake engineering technical field, including the following steps: numerical integration solution;Fast Fourier transform (FFT);Amplification factor solution;Fourier spectrum adjustment;Inverse fast Fourier transform (IFFT);Numerical differentiation solution.The application adopts fast Fourier transform (FFT) to efficiently convert seismic input signal into frequency domain Fourier spectrum, multiply it with displacement amplitude transfer function to obtain Fourier spectrum considering valley topographic effect, reconstructs time domain response based on inverse fast Fourier transform (IFFT), provides an efficient, accurate and engineering generalization scheme for valley topographic effect analysis;Frequency domain processing avoids the discrete error of time domain numerical integration or differentiation, accurately retains the frequency domain characteristics of seismic motion by directly calculating the Fourier spectrum considering topographic amplification effect, ensures the authenticity of topographic amplification effect.

This application belongs to the field of hydraulic systems, and specifically relates to a rapid calculation and application method for spatiotemporally distributed pulsating pressure in hydraulic pipelines. It assumes that the pressure value is the same at all locations on the inner wall of the hydraulic pipeline cross-section, and the cross-sectional pressure is controlled only by the distance from the intersection of the cross-section and the pipeline control spline to the pipeline inlet. The control points belonging to the pipe wall nodes are obtained, and a spatiotemporal distribution function of the pipe wall pressure is established based on the coordinates of the discrete control points and the spatiotemporal distribution of the pulsating pressure. The transient response of the pipeline is calculated based on the spatiotemporal distribution function of the pipe wall pressure, yielding the pipeline's time-domain response. Utilizing the spatiotemporal distribution characteristics of hydraulic pulsations, the spatiotemporally related pressure distribution along the pipeline streamline direction is calculated, and then rapidly applied to the pipeline finite element model. This method omits the unsteady CFD calculation of the flow within the pipeline and allows for rapid application of a spatiotemporally coupled pressure load field to the pipeline finite element model, improving the computational efficiency and iteration speed of the initial design phase of aircraft pipelines.

This invention provides a method and system for designing reconfigurable digital filters based on neural networks, relating to the field of neural network technology. First, a target filter response description containing desired frequency response curve information and time-domain response constraint information is received. This description is then input into a pre-trained reconfigurable filter neural network for direct structural parameter mapping, generating a filter structure description, including filter coefficient parameters and topological connection information. Next, filter response simulation verification is performed based on this filter structure description to calculate the actual filter response description, which is then compared with the target description to generate an error description. Finally, the internal parameters of the neural network are adaptively adjusted and optimized based on the error description, ensuring that the error between the actual response and the target response meets a preset standard. This invention enables rapid, flexible, and accurate design of digital filters, adapting to diverse needs and improving design efficiency.