144 results about "Magnetic parameter" patented technology

The present invention comprises Magnetic Tunnel Junctions and Bit-Patterned Media with a warped geometry with the purpose of attaining large thermal stability factors and dramatically increasing the scalability of the magnetic bits while still allowing the reduction of switching current density and switching magnetic field, and also increasing switching speed. The warped shape allows providing thermal stability to the bits through dynamic exchange energy barrier and also by providing additional net magnetic anisotropy through shape-induced reduction of the demagnetization field. The dynamic exchange energy barrier in turn allows engineering the damping torque and the free-layer's magnetic parameters to a much larger extent than the current planar technology. It also allows much faster magnetic-field-induced switching of patterned bits than it is possible with current hard disk drive technology, through the use of precession torque instead of conventional damping torque.

The invention relates to the technical field of weld joint detection, in particular to a CO2 welding automatic trolley weld joint recognition method. According to the method, by measuring current signals and magnetic conductivity parameters in real time and combining comparison of dynamic change amplitudes, the initial position of a weld joint is accurately recognized, the initial accuracy of weld joint detection is improved, meanwhile, a displacement characteristic curve is extracted, weld joint form data is dynamically adjusted, the continuity and accuracy of weld joint path recognition are ensured, and the path tracking effect is improved; the welding seam boundary and width range are accurately judged in combination with electromagnetic parameter differences, the reliability of welding seam boundary detection is facilitated, irrelevant parameters are removed through frequency selection, edge contours are captured, welding seam surface features are marked, feature point layered clustering and normalization processing are conducted through a Gaussian mixture model, welding seam feature point data are comprehensively integrated, and the accuracy of welding seam boundary detection is improved. The generated feature point model provides an important basis for high efficiency and accuracy of weld joint recognition, and the performance of weld joint detection in the aspects of paths, forms and boundaries is integrally optimized.

The invention discloses a high-precision power supply output correction method based on a digital pre-distortion technology, and relates to the technical field of power electronics, and the method comprises the steps: integrating an electricity-heat-magnetism real-time combined observer, and inputting parameters including a power supply output voltage, a current, a power device junction temperature, a magnetic element surface temperature, an environment temperature, and an input voltage ripple; using a hierarchical memory depth pre-distortion compensator to generate an anti-phase pre-distortion signal containing long time domain thermal constant compensation and short time domain capacitance energy storage compensation based on modeling engine output; based on a double-ring adaptive updating module, an inner ring updates electrical parameters, including on resistance and dead time, by taking a switching period as a reference, and an outer ring updates thermomagnetic parameters, including thermal resistance and a magnetic core saturation point, in a minute-level period; and the DAC is connected in series with a pre-distortion signal output end through an anti-interference execution channel, and comprises a noise shaping DAC and a driving stage for delay matching. According to the invention, through an electric-thermal-magnetic three-field combined observation architecture, the limitation of traditional single physical field monitoring is broken through.

The embodiment of the invention provides a transformer loss monitoring method and a transformer loss monitoring system, and the monitoring method comprises the steps: dynamically updating winding resistance, excitation reactance and iron core magnetic conductivity according to an electromagnetic parameter and a temperature parameter in a state vector space through employing a complex frequency domain parameter identification algorithm which introduces a fusion expansion Cole-Cole model; the no-load loss and the load loss are decoupled through an improved all-electric difference method, the dynamically updated excitation reactance and the iron core magnetic conductivity are used for decoupling the no-load loss, and the dynamically updated winding resistor is used for decoupling the load loss; and taking the decoupled loss data and the associated parameters in the state vector space as the input of an LSTM-Transform hybrid model loaded on the edge calculation module, and predicting and outputting the load loss trend in the future time period. According to the transformer loss monitoring method, the real-time performance, the accuracy and the adaptability of transformer loss monitoring are improved.

The invention discloses a transient electromagnetic and magnetic method data joint inversion method. The method comprises the following steps: acquiring transient electromagnetic observation data and magnetic method observation data; converting the transient electromagnetic observation data into transient electromagnetic moment data; based on the transient electromagnetic moment data and the magnetic method observation data, a joint inversion objective function is constructed, and the joint inversion objective function comprises a data fitting residual term and a model constraint term; performing parameter coupling on the model constraint term by using a multivariate Gaussian mixture model to obtain a coupled model constraint term; and combining the data fitting residual term and the coupled model constraint term into a final objective function, and minimizing the final objective function through an optimization algorithm to obtain an electrical parameter and a magnetic parameter of the underground medium. According to the method, transient electromagnetic and magnetic method data joint inversion is realized, the problem of low three-dimensional inversion calculation efficiency is solved by introducing transient electromagnetic moment, and electrical and magnetic parameters are coupled by utilizing rock physics constraint, so that the inversion result is more accurate, and the structure is more consistent.

The invention relates to the technical field of 8G, and discloses a nuclear fusion plasma real-time control method and system based on a quantum neural network and 8G communication. The method comprises the following steps: transmitting plasma multi-dimensional electromagnetic parameters at a rate greater than or equal to 1Tbps through an 8G terahertz communication network; quantum dimension reduction (the dimension compression ratio is greater than or equal to 98%) and classical time sequence prediction are executed at the edge quantum computing nodes; a control instruction is transmitted to the superconducting magnet array through the photon integrated interface, so that the adjustment of a magnetic field smaller than or equal to 1nm is realized; physical layer quantum encryption is adopted to guarantee communication security, and the secret key distribution rate is larger than or equal to 20 Mbps.

The invention provides an electromagnetic transient simulation method and system for a magnetic valve type current transformer, and relates to the technical field of power system simulation, and the method specifically comprises the steps: collecting electromagnetic, magnetic field, control and environment data, extracting a flux density peak value, a flux density harmonic distortion rate and a current harmonic distortion rate, and constructing monitoring feature data; constructing a data prediction model, dynamically predicting electromagnetic parameters at the next moment, obtaining electromagnetic data, a flux density peak value, a flux density harmonic distortion rate and a current harmonic distortion rate correction value, performing electromagnetic transient simulation through a finite element-circuit coupling model, calculating an amplitude deviation rate and a phase deviation rate, and performing current harmonic distortion rate correction. And generating a running state comprehensive coefficient to judge the running state of the current transformer. Through multi-dimensional data acquisition, time sequence dynamic modeling and coupling simulation, the problems of poor adaptability of fixed parameters, insufficient time sequence characteristic capture and low simulation precision are solved, and the saturation characteristic simulation precision, the transient prediction accuracy and the secondary side current simulation precision are remarkably improved.

The invention discloses a peripheral nerve stimulation threshold prediction method of a magnetic resonance gradient coil and application thereof. The method comprises the following steps: firstly, designing a reference coil group with differentiated electromagnetic parameters based on a target gradient coil space structure; then combining a high-precision virtual human body anatomical model and an electromagnetic-neurodynamics coupling model, calculating the induction electric field distribution and stimulation threshold of each coil, and positioning sensitive neuron nodes; expressing a stimulation function as a weighted sum of a local magnetic vector potential component, constructing a linear equation set, and solving an optimal coefficient by adopting a least square method; and finally, establishing a linear regression model of a stimulation function and a threshold reciprocal, and defining a prediction function based on a local field. The prediction method provided by the invention has both calculation efficiency and prediction precision, can further derive a magnetic resonance coil peripheral nerve stimulation threshold curve for real-time evaluation of stimulation risks in imaging scanning, and can also introduce a coil design framework to realize electromagnetic optimization design of a high-threshold gradient coil.

The invention provides a method for plasma bombardment energy distribution detection and life prediction of a silicon carbide part, and belongs to the technical field of semiconductor processing based on deep learning. The method comprises the following steps: firstly, arranging a magnetic probe array to obtain local electromagnetic parameters, and obtaining plasma luminescence characteristics by using optical imaging and spectrum acquisition equipment; preprocessing the acquired data to obtain multi-source fusion features; designing an energy distribution reconstruction framework based on a generative adversarial network, wherein a generator is used for deducing a three-dimensional energy distribution field of plasma; and inputting the three-dimensional energy distribution field time sequence characteristics into a bombardment dynamic characteristic modeling time sequence depth network, establishing a nonlinear mapping relation between energy distribution and material aging, further obtaining life prediction parameters, and finally obtaining the remaining service life of the silicon carbide part. According to the method, a complex degradation mechanism can be reflected more accurately, and the precision and robustness of life prediction are remarkably improved.

The invention relates to the field of electromagnetism, in particular to a micro-magnetic method for predicting magnetic characteristics of a magnetic sample, which comprises the following steps of: (1) constructing a plurality of magnet models with different magnetic domain sizes, shapes and magnetic domain numbers, and determining magnetic parameters of the magnet models; (2) placing the to-be-measured magnet under a preset external field condition to obtain the magnetization intensity of the to-be-measured magnet, and comparing the magnetization intensity with the measurement result of each model under the same external field condition; (3) determining the similarity between the to-be-tested magnet and each model, finding out the model with the highest similarity, and calling each magnetic parameter of the model; and (4) determining the external field condition of the magnet to be detected in the new target environment.

The invention relates to the technical field of electromagnetic topological optimization, and provides an electromagnetic full-topological optimization method and system for power supply protection equipment, and the method comprises the steps: building a structure model, marking electromagnetic elements and non-electromagnetic elements, building a conduction formula through the information, such as the intensity of a source electric field, the intensity of a source magnetic field, a conduction range, a conduction path, and the like; the distribution conditions of the electric field and the magnetic field are accurately described. Then, the electric field intensity and the magnetic field intensity of any target position on the structure model are calculated based on the conduction formula, then the energy consumption density and the heat level are evaluated, and a to-be-optimized area with too high energy consumption and concentrated heat is recognized. And adjusting electromagnetic parameters of the areas through a preset optimization rule, and continuously calculating and adjusting by adopting an iterative algorithm until an energy efficiency improvement target and a heat limit threshold are reached. The electromagnetic topological structure in the power supply equipment is accurately positioned and optimized, the energy efficiency is improved, the heat is reduced, the optimized specific position and corresponding parameters are finally output, and the equipment performance is optimized and improved.

The invention discloses a method for modeling the electromagnetic thermal dynamic coupling of a permanent magnet synchronous motor based on an equivalent magnetic network, which belongs to the technical field of motor simulation modeling. The method comprises obtaining the material properties and topological structure of the permanent magnet synchronous motor; obtaining the electromagnetic model of the motor according to the material properties and topological structure of the permanent magnet synchronous motor; equivalentizing the internal temperature field of the motor to a plurality of thermal resistance units according to the material properties and topological structure of the permanent magnet synchronous motor, and obtaining the equivalent thermal resistance structure of the motor; obtaining the motor loss based on the electromagnetic model of the motor, and updating the core magnetic permeability of the electromagnetic model of the motor according to the motor loss using the equivalent thermal resistance structure of the motor, realizing bidirectional coupling, and completing the electromagnetic thermal dynamic coupling modeling of the permanent magnet synchronous motor. The invention bidirectionally couples the motor equivalent magnetic circuit model and the motor thermal network model, and can continuously solve the electromagnetic thermal coupling of the motor through iterative updating of the magnetic permeability and magnetic flux with temperature, and realizes the real-time interaction between the electromagnetic parameters of the motor and the motor temperature.

The invention relates to the technical field of simulation modeling analysis, in particular to a simulation modeling analysis method applied to electromagnetic fluid of an alternating current contactor, which comprises the following steps: acquiring armature displacement data in real time through a displacement sensor, and constructing a dynamic mapping relation table containing hysteresis compensation coefficients; dynamically correcting the air gap permeability based on the displacement data and the compensation coefficient, generating an electromagnetic field dynamic coupling boundary condition, and realizing real-time matching of magnetic parameters and mechanical motion; in fluid field simulation, a deformable sub-grid nesting technology is adopted, elastic deformation control is carried out on grids in an electric arc area in combination with a displacement change rate, the influence of magnetic field distortion on the grids is synchronously corrected by associating hysteresis compensation coefficients, and the coupling problem of electric arc dynamic deformation and hysteresis nonlinearity is solved; and meanwhile, a non-arc region is fixed by utilizing a main grid topology keeping module, a deformation sensitive region is screened to execute local grid recombination, and high-precision dynamic simulation of an arc severe deformation region is realized on the premise of ensuring the calculation stability.

The invention discloses a reinforced concrete equivalent electromagnetic parameter processing method for electromagnetic pulse environment time domain coupling characteristic analysis. The method comprises the following steps: firstly, obtaining an S parameter of a reinforced concrete wall structure; then solving a relational expression among the S parameter, the reflection coefficient and the transmission coefficient; then solving a relational expression among the relative dielectric coefficient, the relative permeability, the reflection coefficient and the transmission coefficient; eliminating an intermediate variable reflection coefficient and a transmission coefficient to obtain a relational expression of the relative dielectric coefficient and the relative permeability expressed by an S parameter; and finally, fitting the obtained equivalent electromagnetic parameters into a specific mathematical polynomial form with continuous frequency. According to the method, the multi-valued problem of an equivalent electromagnetic parameter calculation result is solved through imaginary part compensation, frequency domain continuous parameter calculation on a concerned frequency band is achieved through polynomial fitting, and calculation resource consumption of a reinforced concrete complex building model can be effectively reduced; and a method is provided for carrying out time-domain electromagnetic coupling response calculation of the large-size building and the external electromagnetic pulse environment.

The invention discloses a grounding coplanar waveguide with low radiation loss and high signal uniformity, and belongs to the field of magnetic parameter measurement. The grounding coplanar waveguide comprises a bottom metal grounding layer, a medium substrate, a grounding through hole, a signal line, a split signal line and two side metal grounding layers. The dielectric substrate is arranged above the metal grounding layer, two-side metal grounding layers are arranged above two sides of the dielectric substrate, the two-side metal grounding layers are respectively provided with more than two columns of grounding through holes to form a through hole array, a split signal line is arranged in the middle position above the dielectric substrate, and two ends of the split signal line are respectively connected with signal lines. One end of the split signal line is connected with a signal input end, and the other end is connected with a signal output end; the bottom metal grounding layer and the two side metal grounding layers are connected through grounding through holes. According to the invention, the phenomenon of broadening of a test curve caused by non-uniform distribution of a surface magnetic field is avoided, so that the test precision is improved to a great extent, and the radiation loss at a high-frequency position of the grounded coplanar waveguide is reduced.

The invention relates to a soft magnetic alternating-current magnetic performance measuring device and method.The soft magnetic alternating-current magnetic performance measuring device comprises an upper computer, a control unit, an excitation mechanism and a flat high-temperature atmosphere furnace, the control unit is wirelessly connected with the upper computer, the control output end of the control unit is connected with the control input end of the excitation mechanism, a magnetic parameter sample is arranged in the excitation mechanism, and the control output end of the excitation mechanism is connected with the control input end of the flat high-temperature atmosphere furnace; the excitation mechanism and the magnetic parameter sample are arranged in a shell, and the flat plate high-temperature atmosphere furnace is connected with the shell so as to prevent the magnetic parameter sample from being oxidized under a high-temperature condition. According to the invention, a more real and accurate magnetic field condition is acquired by acquiring the lost magnetic flux of the open circuit part through an RCP coil compensation mode, and the measuring device has the characteristics of convenience in operation and accurate result, so that automation is realized.

The invention discloses a residual magnetism measurement method of a ferromagnetic material based on a magnetic Barkhausen noise signal, and belongs to the technical field of electromagnetic parameter measurement. A magnetic Barkhausen noise signal serves as an electromagnetic nondestructive testing signal with huge development potential and has unique advantages in the aspects of detection and evaluation of ferromagnetic metal materials, and the signal generation mechanism of the magnetic Barkhausen noise signal is similar to the generation mechanism of residual magnetism and is related to irreversible magnetic domain rotation and irreversible magnetic domain wall movement; therefore, through two theoretical model formulas of a magnetic Barkhausen noise signal stress detection model based on a J-A magnetization theory and a magnetomechanical model of residual magnetism and stress, a physical model relational expression of a magnetic Barkhausen noise voltage signal peak value and residual magnetization intensity is established by taking stress existing in a ferromagnetic material as an intermediate medium; on the premise that the geomagnetic field can be ignored, the residual magnetism in the ferromagnetic material can be calculated through the measured magnetic Barkhausen noise voltage peak signal according to the constitutive relation, and the method is easy and convenient to operate, reliable in result and wide in applicability.

The invention relates to a high-temperature irreversible magnetic flux loss proportion and residual magnetism prediction method, belongs to the field of high-temperature-resistant permanent magnets, and is particularly suitable for predicting irreversible magnetic flux loss proportion and residual magnetism generated when high-temperature magnets such as SmCo and the like are subjected to high-temperature pre-stabilization treatment. The core of the method is as follows: the irreversible magnetic flux loss proportion and the residual magnetism of a magnet element subjected to high-temperature pre-stabilization treatment at a specific temperature can be accurately calculated only by inputting three key parameters of the geometric shape of the magnet, the knee-point magnetic field intensity with international standards and the residual magnetism, and the method is simple and efficient in calculation process; a reliable and easily-obtained magnetic parameter basis is provided for accurate design of a high-temperature permanent magnet magnetic circuit, and the design efficiency and reliability are remarkably improved.

The invention discloses a coast effect correction method, system and device based on linear iteration and a medium, and relates to the technical field of coast effect correction, and the method comprises the following steps: obtaining a coast effect correction result based on a linear relation among a magnetotelluric impedance tensor, a background impedance tensor of an underground real structure and an impedance tensor of a coast effect; calculating an impedance tensor of the coast effect according to the total electromagnetic parameters and the coast effect-free parameters, calculating a corrected coast effect-free impedance tensor according to the observed total magnetotelluric impedance tensor, and obtaining an intermediate inversion model according to the ocean-free geoelectric model and the corrected coast effect-free impedance tensor; and performing magnetotelluric three-dimensional forward modeling based on the intermediate inversion model and the ocean model, calculating a total magnetotelluric impedance tensor containing the ocean effect, and determining a final inversion model capable of more truly reflecting the underground structure of the region according to the total magnetotelluric impedance tensor containing the ocean effect and the total observation magnetotelluric impedance tensor.

The invention relates to the technical field of low-temperature environment simulation and material characteristic test, in particular to a high-speed rail traction system fault diagnosis method based on electromagnetic parameter fusion, which is used for solving the problems of material electromagnetic characteristic test distortion and fault diagnosis algorithm verification deficiency in a high and cold environment. The method comprises the following steps: constructing a multi-physical field coupling test environment, simulating temperature cycle and humidity sudden change working conditions from-50 DEG C to + 80 DEG C, and synchronously acquiring dynamic parameters of resistivity, dielectric loss and magnetic conductivity; according to the method, the limitation of a traditional static test is broken through, the real representation of the material performance degradation rule is realized, a closed-loop verification system of laboratory and field data is constructed, and the performance of the material is verified. The accuracy and environmental adaptability of fault diagnosis in a high and cold environment are remarkably improved, and reliable guarantee is provided for safe operation of a traction system under an extreme working condition.

The invention provides a gyroscope-assisted geomagnetic calibration method of layered parameter adjustment EKF, and relates to the technical field of sensor data processing and attitude calculation. According to the method, under a traditional EKF framework, a hierarchical selection mechanism for a process noise control parameter alpha and an observation noise adjustment parameter beta is introduced, a historical attitude quaternion and a geomagnetic observation value are subjected to statistical analysis through a sliding window mechanism, a mean value and a variance are calculated respectively, expert voting is carried out according to the deviation degree, and a process noise control parameter alpha and an observation noise adjustment parameter beta are obtained; parameters alpha and beta are dynamically adjusted according to the voting condition, and then the parameters alpha and beta act on a prediction noise covariance matrix Qk and an observation noise covariance matrix Rk respectively. According to the method, real-time optimization of the filter parameters is realized under the condition of not adding extra hardware and complex calculation, the precision and stability of soft magnetic and hard magnetic parameter calibration are improved, and the method has the advantages of being simple to implement, suitable for embedded deployment, high in external magnetic interference robustness and the like.

The present invention discloses a method and device for detecting the diameter of a steel bar based on parameter inversion. Based on the time domain analytical solution of the steel bar pulse eddy current detection model, the induced voltage measurement curve is used to establish a least squares problem between the induced voltage time domain signal measurement value and the theoretical calculation value to invert the diameter, relative magnetic permeability and electrical conductivity of the inspected steel bar. When the relative error sum between the induced voltage measurement curve and the theoretical calculation curve is the minimum, the diameter, relative magnetic permeability and electrical conductivity of the inspected steel bar can be obtained, wherein the inverted steel bar diameter is the detection result, thereby obtaining the size specification of the inspected steel bar. The method and device of the present invention do not require standard test blocks for calibration, can implement more accurate non-destructive detection of the parameters of the inspected steel bar, and eliminate the influence of the electromagnetic parameters of the steel bar on the detection results.

This invention discloses a multi-channel electromagnetic induction detection method and system based on uniform magnetic field constraint. A uniform magnetic field is constructed within the detection area of ​​the structure under test. Electromagnetic induction response signals are acquired through multiple channels under the constraint of the uniform magnetic field, and the spatial coordinates of each acquisition channel are marked. The raw electromagnetic induction signals acquired by each channel are preprocessed, including noise reduction filtering, envelope extraction, and amplitude normalization. A deep learning model is then used to extract structural features from the preprocessed multi-channel electromagnetic response signals. Based on the spatial position information of each acquisition channel, magnetic field uniformity parameters, and response characteristics, a channel correlation weight matrix is ​​constructed to describe the spatial consistency and physical coupling relationships between channels. A multi-channel joint optimization model is constructed, and the equivalent electromagnetic parameter distribution inside the structure under test is reconstructed through iterative solution. This invention improves the reliability, repeatability, and engineering applicability of electromagnetic induction detection results.

The invention relates to the technical field of electromagnetic valve manufacturing and quality detection, and discloses an online detection system for the pressing force of a valve element of an electromagnetic valve, and the system comprises a composite magnetic field excitation module, a multi-physical field signal acquisition module, a multi-dimensional feature resolving module and a force value estimation output module. A composite magnetic field is applied to a valve element, and an induced voltage signal, a Hall signal and a temperature signal are synchronously collected; then, three characteristic quantities of harmonic amplitude, instantaneous magnetic field intensity and instantaneous temperature are calculated; and finally, inputting the three characteristic quantities into a preset multi-dimensional mapping model, and calculating to obtain a pressing force estimated value. The invention aims to solve the problem of low measurement accuracy caused by the fact that the existing single electromagnetic parameter detection is easily interfered by temperature and excitation field fluctuation. And through multi-physical field signal fusion and multi-dimensional feature compensation, the influence of disturbance factors is effectively eliminated, and the accuracy, stability and anti-interference capability of online detection are remarkably improved.

This invention belongs to the field of electrical digital data processing technology, specifically relating to a multi-objective optimization method for improving motor torque performance. The method includes: establishing a parameterized model of the motor; extracting geometric harmonic prior features based on the harmonic analysis principle of the motor's air gap magnetic flux density, and using these as a screening criterion to obtain an initial high-quality sample set; constructing a Kriging surrogate model reflecting the mapping relationship between design variables and performance response, introducing an energy efficiency boundary risk function during the construction process; based on the Kriging surrogate model, using a multi-objective optimization algorithm to search for a Pareto front solution set, selecting potential sample points from the Pareto front solution set for simulation verification, and then adaptively updating the Kriging surrogate model until the stopping criterion is met, at which point the target motor design parameters are output. This invention can achieve accurate optimization of electromagnetic parameters by screening samples through geometric harmonic prior features and utilizing the energy efficiency boundary risk function.

The application belongs to the technical field of magnetic parameter measurement, and discloses a device and a calculation method for testing magnetic force in each direction between permanent magnets. The device uses an electric sliding table and a vertical sliding table to construct a three-dimensional motion platform, and collects the magnetic force of a tile-shaped permanent magnet under different spatial displacements in real time through a sensor. The device can not only meet the force testing needs of the inner / outer rotor permanent magnet under the axial, radial and tangential misalignment states, but also can adapt to different sizes of the inner / outer rotor permanent magnet by adjusting the clamp. Meanwhile, the magnetic force calculation method proposed by the application takes the equivalent magnetic charge model under the cylindrical coordinate system as the theoretical basis, and accurately solves the three-dimensional magnetic force of the inner / outer rotor permanent magnet under any spatial relative position through quadruple integration. With the help of the testing device and the calculation model proposed by the application, the precise measurement and theoretical verification of the magnetic force in each direction of the permanent magnet can be realized, the calculation is simple, and the degree of coincidence is high. The testing and calculation method has engineering universality and convenience.

The invention discloses an electromagnetic torque layered modeling method based on magnetic conductance space attenuation characteristics, and relates to the technical field of permanent magnet motors, and the method comprises the steps: building an electromagnetic parameter expression through motor parameters; determining magnetomotive force parameter expressions of an armature and a permanent magnet through motor pole slot cooperation and a winding mode, and thus obtaining magnetomotive force harmonic waves; according to the condition that the number of magnetic field pole pairs in the electromagnetic parameter expression is the same, an armature magnetic field source generating average torque is limited, and an armature magnetomotive force source is determined to modulate the magnetic conductance order; determining air gap space magnetic conductance through conformal transformation; spatial layering and harmonic attenuation law analysis are carried out aiming at air gap space magnetic conductance, electromagnetic layering torque considering space attenuation characteristics is calculated through magnetomotive force harmonic and magnetic conductance harmonic modulation coupling, and weighting is carried out on the electromagnetic layering torque to obtain the total torque of the motor. According to the method, the torque modeling precision of the permanent magnet vernier motor is remarkably improved.

The present invention discloses a method for processing equivalent electromagnetic parameters of reinforced concrete for analyzing the time-domain coupling characteristics of electromagnetic pulse environments. The method first obtains the S parameters of a reinforced concrete wall structure; then, the relationship between the S parameters and the reflection coefficient and transmission coefficient is calculated; then, the relationship between the relative permittivity and relative magnetic permeability and the reflection coefficient and transmission coefficient is calculated; then, the intermediate variables, the reflection coefficient and transmission coefficient, are eliminated to obtain a relationship expressing the relative permittivity and relative magnetic permeability using the S parameters; finally, the obtained equivalent electromagnetic parameters are fitted into a specific, frequency-continuous mathematical polynomial form. The present invention overcomes the multi-valued nature of the equivalent electromagnetic parameter calculation results through imaginary part compensation, and achieves frequency-domain continuous parameter calculation in the frequency band of interest through polynomial fitting. This method can effectively reduce the computational resource consumption of complex reinforced concrete building models, and provides a method for calculating the time-domain electromagnetic coupling response of large-scale buildings to external electromagnetic pulse environments.

The invention discloses a lossy dispersive medium high-precision electromagnetic calculation method based on a matrix index, and the method comprises the following steps: S1, defining a target space and an excitation source, and determining the positions of the excitation source and an observation point in the target space; s2, dividing the target space into FCC grids, and defining electromagnetic parameters of a lossy dispersive medium and a non-dispersive medium in the target space; s3, initializing electric field and magnetic field parameters of grid points in the FCC grid; and S4, in combination with a matrix index method, carrying out iterative calculation on the electromagnetic field value in a calculation region which is a target space. According to the method, the influence of the actual conductivity of the lossy dispersive medium on the electromagnetic field is considered, and the propagation characteristics of the electromagnetic field in the lossy dispersive medium can be analyzed.

The invention discloses a permanent magnet synchronous linear motor optimal current control method based on a magnetic equivalent circuit model, and the method comprises the steps: considering the nonlinear behavior of a motor, building an accurate MEC model suitable for a PMLSM for a stator part, an air gap part and a rotor part through the electromagnetic quantity of the motor, and building an electromagnetic parameter and thrust balance equation; therefore, an accurate motor thrust expression is obtained, and an optimal current control strategy considering thrust accuracy and coil copper loss minimization is further designed based on the motor thrust expression. According to the MEC model and the corresponding optimal current control strategy, the calculation burden can be reduced on the basis that the model precision is ensured, meanwhile, accurate control over the position and thrust is achieved, the optimal current strategy can further reduce copper loss and improve the efficiency of the system, and high research value and application value are achieved.