319 results about "Numerical stability" patented technology

The invention discloses a seven-degree-of-freedom mechanical arm inverse kinematics solving method, system and device based on numerical iteration. The method comprises the steps that S1, a D-H kinematics model of a mechanical arm is established based on a joint configuration of the seven-degree-of-freedom mechanical arm; s2, calculating a Jacobian matrix according to the joint angle sequence; s3, introducing a weight matrix to suppress the joint speed at the edge of the joint range; s4, introducing a damping factor, and calculating to obtain an optimized Jacobian pseudo-inverse matrix; s5, the pose error between the expected tail end pose and the current tail end pose of the tail end actuator of the mechanical arm is calculated; s6, converting the pose error into a joint angle adjustment amount by using the optimized Jacobian pseudo-inverse matrix to obtain a joint angle iterative formula; and S7, based on the pose error, the joint angle of each rotating joint of the mechanical arm is determined through a numerical iteration method. According to the method, the problem of unstable solution of a traditional analytical method under the singular configuration can be avoided, and the calculation efficiency and the numerical stability are improved.

The invention discloses a sparse Bayesian direction of arrival estimation method based on subspace compression and dictionary optimization, and belongs to the field of array signal processing. According to the method, the data dimension is reduced through the subspace compression technology, and the noise immunity is improved; signal power and noise power are automatically estimated in combination with a sparse Bayesian model, and dependence on information source number information is avoided; the calculation efficiency and the numerical stability are improved through a support set adaptive pruning strategy; and finally, a dictionary fine tuning mechanism is introduced, direction continuous optimization is realized on the basis of an original discrete grid, an off-grid error is eliminated, and direction-of-arrival estimation with sub-resolution precision is realized. The method is a novel method combining subspace compression, sparse Bayesian inference, adaptive pruning and angle optimization, can give consideration to estimation precision, calculation efficiency and application robustness, and is especially suitable for direction estimation under the complex actual conditions of low signal-to-noise ratio, few snapshots, unknown signal source number and the like.

The invention discloses a landslide image instance segmentation method based on a dual adaptation mechanism, relates to the technical field of image processing, and ensures that a model can have a better effect and numerical stability on data from different sources through a complete process from multi-source data collection to data normalization processing. The designed model is based on a multi-scale state alignment mechanism, in the forward process of the model, exponential moving average fusion is carried out on feature information in the same level, transmission fusion is carried out on feature information of different levels, feature robustness is enhanced, and error accumulation caused by local deviation is reduced. A meta-context incremental learning mechanism is designed, and input data are dynamically converted into a series of key value vector sequences. In the reasoning process of the model, data distribution different from a training domain is dynamically recognized, a gradient descent process is implicitly executed according to the characteristics of data, and model parameters are finely adjusted, so that the characterization capability is greatly improved, and efficient and robust instance segmentation is realized.

The invention discloses a coupling algorithm for studying the influence of micro-plastics on fishes based on unstructured grids, and aims to deeply understand the influence of the micro-plastics on fish ecology in the ocean. According to the method, a Lagrange advection model and a diffusion equation are combined to simulate the transmission and diffusion process of the micro-plastic particles, and the spatial position of each particle is calculated and the trajectory of the particle is tracked by introducing real ocean current data. A large-scale sparse linear system generated in the simulation process is solved by adopting a GMRES method, so that the calculation efficiency and stability are ensured. And a Crank-Nicolson method is also utilized to carry out time stepping, so that the numerical stability is improved. The spatial distribution of the micro-plastics is truly reflected by interlacing the time step length and coupling the Lagrange advection and diffusion process. In consideration of specific behaviors of fish schools, the density change rate of the fish schools is jointly determined by inherent movement, diffusion and micro-plastic concentration gradient, so that the potential influence of micro-plastic on marine fish ecology is evaluated.

The invention discloses an oil reservoir polymer flooding process oil-water distribution simulation method and device based on a cellular automaton, equipment, a medium and a product, and relates to the field of oil reservoir engineering and seepage mechanics. The method comprises the steps that rectangular grid division is conducted on an oil reservoir space, three-dimensional coordinates of cellular nodes are determined, and a cellular automaton model is constructed; according to the polymer oil displacement scheme parameters, oil reservoir state parameters at the end moment of water displacement are initialized, and boundary conditions of the mole-type cellular automaton model are established; making an evolution rule for each neighborhood cellular node in the Moire cellular automaton model; according to a numerical value stability rule, adjusting parameters of each neighborhood cellular node in the Mohr-type cellular automaton model; according to the method, a relative permeability nonlinear regulation and control rule is formulated for the Mohr-type cellular automaton model to simulate oil-water distribution in the oil reservoir polymer flooding process of the Mohr-type cellular automaton model, the starting pressure gradient is accurately simulated, and the low-permeability oil reservoir evolution process is accurately described.

On the basis of tight coupling of the SINS and the USBL, a dual-hydrophone differential model is provided, constant errors in USBL measurement are eliminated, and the influence of slant range noise on navigation precision is relieved; a measurement equation of a dual-hydrophone differential model is established, so that the precision and reliability of the integrated navigation system are improved; a robust iterative Kalman filtering algorithm based on approximate least-square estimation is introduced, measurement dimensions are comprehensively evaluated, measurement noise covariance is dynamically adjusted, and the numerical stability and robustness of the algorithm are improved. According to the method, whether the measured data at the current moment is an abnormal value or not is judged according to previous data, the robust weight is reasonably distributed to the measured data, the adverse effects of subsequent steps such as state estimation are reduced through a method of reducing the weight of the abnormal value, and normalization operation is carried out on the measured residual error according to the adverse effects, so that the residual error distribution is more regular, and the accuracy is improved. And the updating result of the measurement noise covariance is further optimized, so that the precision of the whole Kalman filtering algorithm is improved.

The invention relates to the technical field of cable joint temperature monitoring, and discloses a cable joint temperature monitoring method and system. A target model is constructed based on equipment data of a cable intermediate joint, regions are divided according to geometric shapes and materials to form a topological structure, and an initial thermal circuit model is constructed in combination with temperature field distribution and a thermal resistance branch; and optimizing the model by using the real-time temperature data, and finally judging the running state of the joint through the thermal circuit model. Complex grid discretization is replaced by an equivalent thermal resistance branch through a thermal circuit model, and the calculation speed is remarkably increased; through topological structure division, the limitation of an analytical method on a regular shape is broken through, and a special-shaped structure can be accurately processed; and the thermal circuit model maps an actual boundary through a thermal resistance parameter, so that an error caused by boundary simplification in an analytical method is avoided. The technical problems that a numerical method and an analytical method adopted by a traditional cable connector need to consider grid division and numerical stability, so that the calculation speed is low, and complex geometrical shapes and boundary conditions cannot be accurately analyzed are solved.

The invention discloses a semiconductor device critical breakdown characteristic simulation method based on a hybrid finite volume method. The method comprises the following steps: firstly, carrying out geometric modeling on a device, and carrying out mesh generation; then, the quality of the grids is judged, an FBM method is adopted for the grids with the good quality, and a CVFEM method is adopted for the grids with the poor quality to discretize a drift-diffusion equation set; and then, solving the discrete drift-diffusion equation set system by adopting a full-coupling Newton iteration method, and realizing the optimization of the boost numerical simulation process by adopting an automatic boost strategy and an initial value extrapolation method. And finally, obtaining physical field information of a power semiconductor device (LDMOS) under different external bias voltages, calculating terminal current through a post-processing method, and obtaining an I-V characteristic curve of the device after the avalanche breakdown effect is considered. The method has good numerical calculation precision, numerical stability and grid adaptability, and the complete benchmarking with the solution precision of an international advanced semiconductor simulation tool Sentaur TCAD is realized.

The invention discloses a double-tower system process optimization method based on LU decomposition, and the method comprises the steps: taking the total value of a liquid phase product produced by a double-tower system formed by a depropanizing tower and a debutanizing tower as an optimization target, and constructing an optimization model by combining a constraint equation and a normalization equation; and performing iterative solution on the optimization model based on LU decomposition and a quadratic sequence programming method. According to the method, by judging the correlation of the constraint equation and optimizing the condition number, the influence of ill-conditioned problems can be effectively avoided, and the numerical stability in the solving process is remarkably improved. According to the method, the redundant constraint equation is removed, and the condition number is improved through LU decomposition basis changing, so that unnecessary calculation can be reduced, and the convergence speed of iteration is improved.

The invention relates to an overlapped chromatographic peak positioning and splitting method and system based on a numerical stable function. The method comprises the following steps: de-noising chromatographic data and correcting a baseline; calculating a second derivative by using SG filtering, grouping continuous points according to a negative threshold value, and determining an initial position of each peak by using a second-order minimum value; establishing a peak function of bidirectional exponential correction by taking a peak position as an initial value, setting parameters and boundaries such as area, center, width, trailing and the like, constructing a residual error minimization target, and performing robust fitting by adopting a trust region reflection algorithm; and indexes such as suitability, output peak area, center, broadening, separation degree, theoretical plate number and the like are verified by residual errors. According to the method, valley point or prior component information is not needed, the method is insensitive to noise and baseline drift, serious overlapping and trailing / leading edge peaks of multiple components can be effectively processed, convergence is high, the method is insensitive to initial values, parameters can be expanded to different peak shapes, and the method is suitable for qualitative and quantitative analysis of automatic and high-flux chromatographic data.

The invention belongs to the technical field of crossing of artificial intelligence and computational mechanics, and particularly relates to an artificial intelligence-based MPM simulation method and system for a mold bag sand cofferdam, a three-dimensional simulation system of the mold bag sand cofferdam is constructed in combination with an MPM method, and the penetration state of sand and geotechnical cloth is detected in an accelerated manner by utilizing a penetration tracking algorithm and spatial Hash. An artificial intelligence algorithm is introduced, a reward function is designed with minimum penetration depth and penetration times as targets, penetration prediction of MPM particles is driven, the speed and stress of the MPM particles are further dynamically regulated and controlled on the basis of a predicted contact model and the artificial intelligence algorithm, penetration is prevented, numerical stability is ensured, and the prediction accuracy of the MPM particles is improved. The calculation precision is improved by adopting implicit integration and gradient descent methods; and bidirectional coupling of the sand and the geotechnical cloth is realized through a visualization module. The problems that in a traditional method, coupling simulation of sandy soil and a flexible structure is low in efficiency, easy to penetrate, unstable in numerical value and the like are solved, and the accuracy and reliability of simulation analysis of the mold bag sand cofferdam structure under the complex working condition are remarkably improved.

The invention provides a dynamic state estimation method for minimum information loss of a heat network and a gas network of a multi-energy system, and the method comprises the steps: building all subsystems of a comprehensive energy system and a multi-energy system coupling equipment model based on different physical characteristics and different time scales of an electric system, a heat system and a gas system; establishing a heat supply network state estimation model and a pseudo-dynamic state estimation model based on each subsystem and the multi-energy system coupling equipment model; substituting the parameters of the pre-estimated moment into a heat supply network state estimation model to obtain a heat supply network state estimation value; and substituting the parameters of the pre-estimated moment into the quasi-dynamic state estimation model, and solving the quasi-dynamic state estimation model by adopting an alternating direction multiplier method to obtain a gas network state estimation value. According to the method, a nonlinear problem in state estimation is converted into a linear problem, the accuracy of state estimation is greatly improved, the contradiction between the calculation complexity and the solution accuracy in the dynamic calculation of the multi-energy system network is well balanced, the numerical stability is good, and the calculation efficiency is high.

The invention provides a multi-source data fusion correction method for a marine observation station, which belongs to the technical field of marine observation, and comprises the following steps of: establishing a hierarchical interpolation correction model comprising a weighted moving average algorithm and a space collaborative interpolation algorithm, and constructing a marine environment adaptive threshold adjustment mechanism based on a closed-loop feedback system; a Kalman filter is combined with a multi-factor coupling drift prediction model of a long-short-term memory network, a progressive degradation fusion strategy switched according to environmental conditions is designed, and a biological pollution gradual change detection correction model adopting a liquid neural network structure is constructed. A multi-source data quality evaluation system based on data continuity, numerical stability, consistency and historical reliability is established, high-precision self-adaptive fusion correction of the marine environment multi-source sensor data is achieved, and the technical problem that high-precision self-adaptive fusion correction of the marine environment multi-source sensor data is difficult to achieve is solved.

The invention discloses a thermal-fluid-solid medium seismic wave simulation method, device, program and medium, and relates to the technical field of oil and gas resource geophysical exploration, and the method comprises the following steps: constructing a first-order thermal-fluid-solid coupling wave equation in an equation coupling form; constructing a coupling wave equation staggered network finite difference discrete format; analyzing numerical stability conditions; constructing a complete matching layer absorption boundary; and performing forward modeling simulation of seismic waves in the three-layer heat-fluid-solid coupling model according to the model parameters and the seismic source parameters. The method breaks through the assumption that the classical seismic wave propagation theory is completely elastic under the isothermal or adiabatic deformation condition, considers the influence of temperature change on the propagation of seismic waves in fluid and solid media, and improves the description precision of the propagation process of the seismic waves in the heat-fluid-solid media. And the capability of inverting the underground temperature field based on seismic wave data in the later period can be effectively improved.

The invention discloses a system Gaussian filter design method for multi-step measurement of random delay and colored measurement of noise. A first-order autoregression model is introduced to whiten the colored measurement noise, and a system with the colored measurement noise is converted into a nonlinear system with normal white noise; modeling delay measurement data by means of a Bernoulli random variable, processing multi-step random delay by taking new system measurement noise as a state increment, realizing one-step prediction of delay measurement information, and finally establishing a nonlinear system state model and a measurement model with multi-step measurement random delay and colored measurement noise. And an unscented transformation mode is adopted to approximate non-Gaussian weighted integral, and an unscented Kalman filtering algorithm under the conditions of multi-step measurement random delay and colored measurement noise is provided. According to the method, the accuracy of the filter in processing multi-step measurement random delay and colored measurement noise is improved, the deviation in a filtering result is reduced, and higher precision and better numerical stability are achieved.

The invention provides an electromagnetic transient simulation method and system containing a synchronous generator, and is applied to the technical field of electromagnetic transient simulation of a power system. The electromagnetic transient simulation method comprising the synchronous generator comprises the following steps: acquiring a simulation equation of a circuit system to be simulated comprising the synchronous generator and a value of an electromagnetic transient state quantity of the circuit system at an initial moment; based on the value of the electromagnetic transient state quantity at the initial moment, adopting a Runge-Kutta algorithm to simulate the simulation equation to obtain a simulation value of the electromagnetic transient state quantity of the circuit system at the target moment; wherein the simulation equation is a port Hamiltonian form equation constructed based on the structure of the circuit system to be simulated. The port Hamiltonian-form simulation equation can keep numerical stability for a long time, calculation errors are reduced, an accurate and stable numerical solution can be obtained, and the requirements for long-time operation accuracy and stability in electromagnetic transient simulation numerical calculation are met.

A soft tissue modeling method in a virtual operation based on biomechanical characteristics comprises the following steps: 1) setting a mass point spring system, and establishing a kinetic equation for each mass point; 2) moving least square method approximation of a displacement field; 3) simulation updating: calculating a new displacement field by using MLS approximation, and ensuring physical constraints; 4) solving a kinetic equation, and solving the equation by using an implicit Euler method to obtain system response changing along with time; and (5) iteration and adjustment are carried out, an implicit Euler method is used for solving the equation, and system response changing along with time is obtained. According to the method, the biomechanical characteristics of the soft tissue are effectively simulated by adding multiple functional springs, then the MLS method is integrated into the mass point spring model, the capacity of the model for processing complex deformation and large displacement events is enhanced, meanwhile, the overall numerical stability and accuracy are improved, and the method is suitable for large-scale popularization and application. And the established soft tissue model is more suitable for the requirements of a virtual operation system.

The invention discloses a multi-view image Gaussian reconstruction method and system guided by LiDAR point cloud. The method comprises the following steps: step S1, realizing accurate registration of LiDAR point cloud and a multi-view image in the same earth-centered earth-fixed coordinate system through GNSS constrained aerial triangulation, and uniformly carrying out center-of-gravity normalization to ensure space consistency and numerical stability; s2, estimating surface normal and scale parameters based on the local geometric features of the LiDAR point cloud, constructing a Gaussian ellipsoid consistent with the local geometry, and realizing Gaussian ellipsoid initialization of geometric perception; and S3, generating a sub Gaussian ellipsoid according to the Gaussian gradient and the tangent plane direction, and improving the modeling density and geometric continuity of the detail region through local encryption and parameter inheritance. According to the method, the fusion of LiDAR point cloud high-precision geometry and multi-view image texture information is realized, the geometric precision, the structural integrity and the detail expression capability of three-dimensional reconstruction are effectively improved, and the method is particularly suitable for high-precision live-action three-dimensional modeling of unmanned aerial vehicle multi-view images.

The invention relates to a fractional order PID (Proportion Integration Differentiation) control method and system based on an FPGA (Field Programmable Gate Array). The method comprises the following steps of: 1, setting fractional order PID related parameters according to the requirements of a controlled object; 2, calculating a fractional order calculus weight coefficient according to the fractional order PID related parameters, and storing the fractional order calculus weight coefficient in the FPGA; 3, collecting a state feedback signal of the controlled object, and calculating an integral term operator and a differential term operator; step 4, calculating control output and performing amplitude limiting processing, and updating the state of the controlled object by using the control output after the amplitude limiting processing; and 5, repeating the steps 1-4 to realize fractional order PID closed-loop control. By optimizing a discrete convolution algorithm, adopting a parallel pipeline architecture and configurable parameter design and combining fixed-point number operation and security boundary constraint, the numerical stability and hardware security of the system under high-speed operation are ensured, the calculation speed is remarkably increased while the operation precision is ensured, and the method is suitable for large-scale popularization and application. And the method is suitable for control occasions with extremely high real-time requirements.

The invention discloses a high-order multi-scale finite element method and system for chip multi-physics field simulation. According to the method, a designed chip model is embedded in a regular coarse background grid, and the problem of numerical instability caused by unit cutting can be caused by embedded simulation. Therefore, ill-conditioned coarse nodes of a coarse unit are judged based on a boundary interpolation function; furthermore, a reduced coarse unit is constructed by removing an ill-conditioned boundary interpolation function, so that a good condition number is ensured. Therefore, a numerical value shape function capable of reflecting internal material distribution is constructed on the coarse background grid for subsequent simulation. On the premise of keeping the solving precision, the calculation cost is reduced, the numerical stability of embedded simulation is improved, and the method has huge potential in super-large-scale boundary complex structure simulation. The method is suitable for multiple simulation fields of statics, dynamics, thermal fields and the like, and the numerical stability, simulation precision and calculation efficiency advantages of the method are verified in statics and thermal field simulation.

A linear memory attention system and method implements an iterative process to compute attention by first computing partial first and partial second attention components for a token for each iteration. From these partial first and partial second attention components for each iteration, respective first and second attention components are then determined. On the final iteration for the token, attention for the token is computed by dividing the second attention component by the first attention component. In an implementation, a normalization scaler is used to ensure numerical stability. In an implementation, parallelism is achieved by splitting queries into chunks of constant size and processing the keys and values of the chunks. The use of checkpointing facilitates a more efficient use of memory and allows for recomputation during backpropagation.

The invention discloses a method for improving the solving speed of a rotating sphere non-singularity electromagnetic scattering field, and belongs to the field of electromagnetic engineering. Aiming at the electromagnetic scattering problem of a rotating structural body in the field of practical engineering, the invention provides a method for improving the non-singularity electromagnetic scattering field solving speed of a rotating body, and effective analysis of the rotating body is realized based on a moment method. A rotating structure body has important application value in electromagnetic radiation and scattering research due to geometric symmetry, but under the condition of long wavelength, a traditional surface integration method often has the problem of singularity, and numerical stability and precision are affected. Therefore, a method for effectively eliminating singular integrality and converting a dense matrix needing to be solved into a sparse matrix is designed, the calculation efficiency is remarkably improved, and the memory consumption is reduced. A non-singularity surface integral equation is obtained through derivation, simulation and numerical simulation are carried out through a specific electromagnetic rotating body device model, an efficient numerical solution is provided for the electromagnetic scattering problem, and the method has wide engineering application prospects.

The invention relates to the field of aero-engine complete machine full-three-dimensional numerical simulation, and discloses an aero-engine complete machine full-three-dimensional simulation initial field presetting method and system, and the method comprises the steps: obtaining initial flow field boundaries of different parts from the zero-dimensional level of a complete machine by solving inlet section parameters and outlet section parameters of each part; then obtaining an initial field of each blade row in a turbine part, which has the most critical influence on the convergence of an engine, through a quasi-three-dimensional layer S2, and realizing initial field decomposition from the part to the part; and finally, by adopting a radial basis function interpolation method, mapping the zero-dimensional data and the S2 quasi-three-dimensional parameters to each grid unit of the complete machine full-three-dimensional model of the aero-engine, and then smoothly splicing the initialized flow fields of all the components at the interface to form a continuous complete machine three-dimensional simulation initial field under the examination working condition. The convergence of a whole machine simulation example, the simulation convergence speed and the numerical stability are greatly improved, the simulation trial and error iteration is reduced, the pretreatment time consumption is reduced, and the simulation speed and efficiency are improved.

The invention discloses a hydropower station reservoir runoff intelligent forecasting method based on a large language model, and belongs to the technical field of hydrological forecasting, and the method comprises the following steps: S1, data collection and preprocessing; s2, constructing a BERT-Hydrology deep learning model for the runoff forecast of the reservoir of the hydropower station; s3, designing a weighted mixed loss function, and introducing an optimizer, learning rate scheduling and an early stop mechanism to improve the convergence speed and numerical stability of model training; and S4, establishing an evaluation system, performing rolling forecasting, and outputting an evaluation index and a significance test result. According to the intelligent hydropower station reservoir runoff forecasting method based on the large language model, the accuracy and the stability of runoff forecasting are remarkably improved by constructing the runoff forecasting model, excavating the hidden rule in the hydrological sequence and establishing the multi-step forecasting mapping, and the forecasting accuracy and the forecasting stability are improved. And technical support is provided for intelligent scheduling of a hydropower station reservoir and efficient management of water resources.

The invention discloses a pulverized coal combustion soot generation numerical calculation method based on an orthogonal moment method, and belongs to the technical field of soot simulation. According to the method, through coupling of an improved split-based extended orthogonal moment method (S-EQMOM) and a small flame model and in combination with a detailed chemical reaction mechanism, the problems that multi-modal distribution of soot cannot be accurately described and the numerical stability is insufficient in a traditional method are solved. The method comprises the specific steps that a gas-particle two-phase control equation is established, and a population balance equation is solved through an S-EQMOM split number density function; discretizing the processing model and coupling a pressure-velocity field; physical and chemical behaviors such as pyrolysis, nucleation and coagulation in the soot generation process are analyzed. According to the method, by decomposing the complex dynamic process, numerical error accumulation is reduced, calculation stability is remarkably improved, the soot volume fraction, particle size distribution and other attributes can be accurately predicted, and theoretical support is provided for design of the pulverized coal burner.

The invention discloses an industrial robot motion pose error calibration method based on constraint solution. The industrial robot motion pose error calibration method comprises the steps that S1, joint angles, tail end coordinates and temperature data of multiple measurement points are collected; s2, correcting the kinematic model by using the thermal elongation and constructing a parameter identification model; s3, constructing a mixed integer nonlinear constraint pool according to mechanical limitation; s4, introducing a semi-definite programming slack variable to convert the non-convex constraint into a linear matrix inequality; s5, combining a primal-dual interior point method and an alternating direction multiplier method to iteratively solve the optimal kinematics parameter correction; s6, introducing a square root information filtering improvement mechanism to correct a state vector square root factor, and calculating an updated nominal kinematics parameter; and S7, based on the condition number of the error Jacobian matrix, judging observability and repeatedly calibrating. According to the method, the problem of precision reduction caused by thermal errors is solved, and the identification precision, the numerical stability and the self-adaptive calibration capability of the kinematics parameters of the robot are improved.

The invention relates to the technical field of solid oxide fuel cells, and discloses a construction method of a solid oxide fuel cell multi-physical field bidirectional strong coupling simulation model and a computer program product. The method comprises the following steps: respectively constructing an electrochemical model, a positive / negative electrode fluid flow model and a heat transfer model of the solid oxide fuel cell based on an established geometric structure model; solving equations of the physical fields in all the models are combined to form a full coupling matrix, and iterative solving is carried out according to a set initial value; and judging whether the constructed model is converged or not according to an iterative solution result. According to the model constructed by the method, the mutual influence among electrochemistry, flow and heat transfer processes is fully considered, and synchronous solving is performed through a unified matrix system, so that real-time interaction and collaborative updating among multiple physical fields are realized, and the convergence efficiency and numerical stability of a nonlinear coupling problem are remarkably improved; through inspection, the deviation between a simulation result and actually measured data is less than 8%, and the method has high engineering practical value.

The invention relates to the technical field of electromagnetic transient simulation, in particular to an electromagnetic transient simulation decoupling method, system and device based on a single-impedance branch and a medium, and the method comprises the steps: dividing a system to be simulated into two subsystems which are connected through the single-impedance branch, and carrying out the equivalent reconstruction to form a reconstructed branch model; establishing a discrete state space equation based on the reconstructed branch model; according to the main step length, the number of sub-steps meeting the stability condition is determined based on a small-step synthesis algorithm, and the main step length is equally divided into differential step lengths; in each main step length interval, performing iterative calculation on the state-space equation by using a differential step length to obtain a branch current and a capacitor voltage at the next moment; and injecting the calculated branch current serving as a known current source into an original network equation, solving in parallel to obtain the port voltage of the subsystem, and completing decoupling calculation and promoting simulation. According to the method, effective decoupling of the universal single-impedance branch can be realized, and the applicability, the numerical stability and the calculation efficiency of parallel simulation are improved.

The invention discloses a three-winding transformer power frequency impedance online monitoring and decoupling identification method and system. The method comprises the steps of collecting and preprocessing multi-dimensional operation data of the three-winding transformer, and constructing a feature set to invert real-time topology, load working conditions and energy flow distribution; establishing a power frequency impedance identification model, and introducing an identification stability factor for decoupling calculation of high, medium and low voltage side impedance parameters; and fusing the time sequence variable quantity and historical data, constructing a health degree evaluation index based on the dynamic impedance change rate, and realizing fault early warning and abnormity positioning. Aiming at the problem of error amplification of a parameter identification equation, concepts such as an identification stability factor and a dynamic impedance change rate are introduced, related factors influencing the numerical stability of the equation are deeply analyzed, a scheme for adjusting to-be-solved parameters according to energy flow is provided, adaptive matching is realized in combination with big data, and an online monitoring method is constructed. And multi-stage early warning of the winding state is realized.

The invention discloses a pump turbine flow-induced vibration multi-scale coupling calculation method, and belongs to the technical field of pump turbine fluid-solid coupling dynamics. According to the method, the gap flow effect is included in a multi-scale unsteady fluid-solid coupling analysis framework of the pump turbine, the gap drainage basin is included in three-dimensional modeling of the pump turbine, the three-dimensional model is subjected to grid division by adopting a multi-scale grid technology, and a small transition region is arranged between a movable guide vane and a rotating wheel, so that the gap flow effect is obtained. The transverse direction is consistent with a main runner grid, and the longitudinal direction corresponds to a gap grid, so that data coordination of large-scale and small-scale regions is realized. A fluid-solid coupling solving method of a bidirectional iteration strategy is adopted, a flow field and a structure field are solved respectively, a system coupling module carries out load transmission and coordinated updating in a residual weighting and node mapping mode, the physical consistency and numerical stability of coupling simulation are effectively improved, and the system performance is improved. The method has remarkable advantages in the aspects of improving simulation precision, enhancing calculation stability, improving design efficiency and the like.