97 results about "Electric field computation" patented technology

The invention discloses a prediction method for electrode air gap breakdown voltage. The prediction method comprises the steps of firstly measuring breakdown voltage of typical electrode air gaps in different structures, and defining a withstand voltage interval and a breakdown voltage interval; then performing electric field calculation to the typical electrode air gasp in different structures, extracting electric field characteristic quantity and establishing a training sample set; establishing a breakdown voltage prediction model based on the training sample set, wherein the breakdown voltage prediction model takes the electric field characteristic quantity as input and the withstand voltage interval and the breakdown voltage interval as output; finally, predicting the breakdown voltage of an electrode air gap by adopting the breakdown voltage prediction model. The prediction method for the electrode air gap breakdown voltage has the advantages that the operation process is simple, the prediction accuracy is high, the period is short, the cost is low, the prediction method is suitable for engineering application and the prediction result can be used for guiding power transmission and transformation engineering design.

The invention discloses an electrode critical coronal voltage predicting method on the basis of characteristic quantities of electric fields, which comprises the following steps: firstly, measuring critical coronal voltage data of typical electrodes which are of different structures and defining a non critical coronal voltage interval and a critical coronal voltage interval; then carrying out electric field calculation on gaps between the typical electrodes which are of different structures and extracting the characteristic quantities of the electric fields so as to construct a training sample set; nextly, on the basis of the training sample set, constructing a critical coronal voltage predicting model, wherein the critical coronal voltage predicting model uses the characteristic quantities of the electric fields as inputs and uses the non critical coronal voltage interval and the critical coronal voltage interval as outputs; and finally, predicting critical coronal voltages of the electrodes by adopting the critical coronal voltage predicting model. The electrode critical coronal voltage predicting method is simple to operate, has high predicting accuracy and is suitable for predicting the critical coronal voltage of the electrode which is of a random structure; and a predicting result can provide reference for structural design and structural optimization of a power transmission line, fittings, an electrostatic dust collection device and the like.

The invention provides a calculation method for a synthetic electric field of an ultrahigh voltage direct-current transmission line crossing a complex terrain. The calculation method comprises the following steps: S1. establishing a synthetic electric field calculation model including a line coordinate parameter and a terrain parameter; S2. randomly setting one point on the surface of a transmission conductor, and determining a power line starting from the point; S3. setting an initial value of electric charge density of the surface of the transmission conductor, and determining the electric charge density and a scalar function of space points starting from the surface of the transmission conductor and along with the power line; and S4. calculating the synthetic electric field according to the determined electric charge density and the scalar function. Based on a Deutecsh assumption principle, rugged topography factors in the calculation process can be introduced by combining an electric charge simulation method, the calculation accuracy of the synthetic electric field can be greatly improved, so that the evaluation accuracy on an electromagnetic environment of the high-pressure direct current transmission line can be improved, and the situations that the calculation difficulty is improved and the calculation amount is increased when the terrain factor is introduced in a traditional algorithm can be also prevented.

The invention discloses a ground penetrating radar large-scale three-dimensional forward modeling method based on the FDTD. According to the method, data exchange of nodes is carried out through a network, and communication and synchronization of the nodes are achieved; a measured point in any node is selected to be subjected to forward modeling parallel calculation on the basis of the FDTD, firstly, an electric field value is calculated, magnetic field calculation is carried out by adding an excitation source after electric field calculation is finished, iteration is continuously carried out through communication, electric field calculation and magnetic field calculation, and when calculation of the set time total step length is finished, calculation is stopped, output data are stored, the data serve as a radar reflected signal of the measured point; initialization updating is carried out on all field values, a whole computational domain recovers to the state before calculation, and then a transmitting antenna and a receiving antenna are moved to a next measured point to start forward modeling calculation again; if calculation of all the measured points is finished, data of all the nodes are collected to carry out imaging and image postprocessing. The ground penetrating radar large-scale three-dimensional forward modeling method based on the FDTD is applicable to calculation of dielectrics and models with complex scales, has the advantage of being high in universality, and is especially applicable to large-scale and high-precision forward modeling.

The invention provides a power frequency electric field computing method for a rolling ground overhead transmission line based on a charge simulation method. The method comprises the following steps that a, a mirroring ground is selected, and it assumes that the mirroring ground extends into a rolling ground; b, simulated charges and matched points corresponding to the simulated charges are arranged on a wire and a non-mirroring ground, and the electric potential of the rolling ground is made to be zero; c, on the basis of the superposition principle, a simulated charge equation set is constructed, and the simulated charges are solved according to the simulated charge equation set; d, power frequency electric field distribution of the rolling ground is computed according to the simulated charges. The method is based on the image theory and combined with the simulated charge optimization method, the electric field distribution of the complex terrain where an overhead conductor path passes through can be computed, the technical problem that the electric field distribution of the rolling ground cannot be accurately computed in the traditional method is effectively solved, accuracy of power frequency electric field computation of the conductor path is effectively improved, computation difficulty is greatly lowered, the computation quantity is reduced, computation precision is further improved, and the adaptability of the electric field computation method is enhanced.

The invention relates to a calculation method for a ground resultant electric field of a DC transmission line. In the method, a practical transmission line is modeled by finite elements so as to calculate the ground resultant field of the DC transmission line, the in modeling process, the calculation accuracy for the electric field on a conductor surface is improved by a sub-domain; based on mathematical methods, the electric field with existence of space charge is calculated, and finally, the more accurate ground resultant field calculation method is obtained. The test data obtained from tests shows that the method of the invention has higher accuracy, and can be used for calculation of the DC resultant field of a high-voltage DC power line in the future.

The invention belongs to the technical field of multi-physics coupling computing of a converter transformer, in particular to a calculation method of a composite electric field of the converter transformer considering temperature gradient. The calculation method comprises the steps that firstly, loss of transformer core and winding is calculated; next a fluid-temperature field model of the converter transformer is established, the fluid-temperature field model is discretized into a triangular-quadrilateral network, the distribution of a temperature field when heat flux is coupled inside a fueltank is calculated and analyzed by utilizing a magnetic field loss as the heat source. According to the electric field characteristics, an electric field model is established and divided into a triangular network, and temperature results of a fluid-temperature field are mapped into the electric field model through a fast mapping method; finally, a power transmission system model is built, a ground voltage wave is transformed to the frequency domain, and the results are returned to the time domain by utilizing the Fourier inverse transform, and a non-sinusoidal steady-state alternate current / direct current composite electric field of the converter transformer is analyzed and compared under the condition of homogeneous temperature and non-uniform temperature. The method considers the existence of temperature gradient, improves the calculation accuracy, and makes the calculation results more accord with an actual situation.

The invention relates to an atmospheric electric field calibration system with high precision and wide range. The atmospheric electric field calibration system comprises an electric field generator (21), a direct-current high-voltage power supply (22), a direct-current middle-voltage power supply (23), a direct-current low-voltage power supply (24), a high precision high-voltage ammeter (25), a digital ammeter (26), a high precision digital ammeter (27), a data acquisition card (28), an equal precision universal counter (29), a universal oscilloscope (210), a universal computer and data processing module (211), a super isolating transformer (213), an independent specific grounding wire (214) and the like; the atmospheric electric field calibration system is characterized in that the most important equipment of the atmospheric electric field calibration system with high precision and wide range is the simulation electric field generator (21), and the ratio of the diameters to the distance of high and low level plates is not less than 3. The total design error of the electric field calibration system provided by the invention is 1%; and the electric field calibration range is 0-100kV / m, the precision is high, the range is wide, and the interference resistance is strong.

The invention relates to an electric field analysis-based super high-voltage direct current transmission converter valve fault diagnosis method, comprising the steps of extracting structural parameters according to an actual model of a converter valve; establishing an electric field computing model of the converter valve according to the extracted structural parameters; selecting the electric field type to be applied to the electric field computing model of the converter valve and setting corresponding excitation and boundary conditions; performing electric field analysis on the electric field computing model of the converter valve, judging whether an insulation fault occurs, and positioning the fault occurring position. From the property of the electric field, the electric field computing model capable of reflecting the insulation characteristics of the converter valve can be accurately established, and the reasonable use of the computer resource is ensured; the insulation features of the insulation structure can be analyzed according to the actual condition under different work conditions, the position easily subjected to local discharging is judged, and the fault occurring position is accurately positioned.

The invention relates to a magnetic-resonance radio-frequency coil performance evaluation method, which comprises the steps of establishing a magnetic-resonance multi-channel radio-frequency coil model and starting the multi-channel radio-frequency coil model to produce an excited magnetic field; loading a digital human model in the multi-channel radio-frequency coil model; calculating the electromagnetic field of each coil channel in the multi-channel radio-frequency coil model when the digital human model is loaded; calculating the coil sensitivity of the multi-channel radio-frequency coil model according to the magnetic field of each coil channel; calculating the noise coupling matrix of the multi-channel radio-frequency coil model according to an electric field produced by each coil channel; calculating the signal-to-noise ratio of the multi-channel radio-frequency coil model according to the coil sensitivity and the noise coupling matrix. The magnetic-resonance radio-frequency coil performance evaluation method has the advantages that the actual measurement environment is not required to be established, the performance of magnetic-resonance radio-frequency coils can be conveniently and quickly evaluated and the manpower and the material resources are saved. Moreover, the invention additionally provides a magnetic-resonance radio-frequency coil performance evaluation system.

The invention discloses a three-dimensional alternating electric field sensor calibrating device. The calibrating device includes a voltage regulator circuit unit, a sensor position control unit, a sensor output detection unit, and a calculation unit, the voltage regulator circuit unit is used for generating an alternating electric field between the upper electrode and the lower electrode of an electrode structure unit and for outputting the generated alternating voltage to the calculation unit, the sensor position control unit is used for controlling the position of a sensor according to the preset position, the sensor output detection unit is used for receiving the electric field output value detected by the sensor and sending the electric field output value to the calculation unit, the calculation unit is connected with the voltage regulator circuit unit and the sensor output detection unit and is used for simulating a three-dimensional alternating electric field, for calculating the different preset positions under different electrode structures and the corresponding actual electric field values under different voltages according to the simulated three-dimensional alternating electric field, and for calculating the calibration coefficient based on the linear relationship between the actual electric field value and the electric field output value. The calibration coefficients can be calculated automatically based on the sensor output value and the actual value of the electric field intensity under the different electrode structures, sensor positions and voltage conditions.

A disclosed specific absorption rate measurement system according to an embodiment of the present invention measures a specific absorption rate of electromagnetic waves from a radiating source absorbed in a dielectric medium. The system includes a measurement portion that measures a first electric field vector on an observation surface which is a two-dimensional surface in the dielectric medium; an electric field calculation portion that calculates a second electric field vector in a point excluded from the observation surface in accordance with electric field components of the first electric field vector measured on the observation surface, the electric field components being parallel to the observation surface; and a calculation portion that calculates the specific absorption rate from the calculated second electric field vector.

The invention provides a calculation and optimization method for a high-voltage alternating current / direct current parallel line mixed electric field. The method comprises the following steps that: determining the relevant information of a high-voltage alternating current / direct current parallel line, and constructing a two-dimensional mixed electric field calculation model according to the relevant information; aiming the voltage class of a corresponding high-voltage alternating current / direct current power transmission circuit and an interval space between an alternating current circuit anda direct current circuit, adopting a meshfree method to carry out a solving operation on a calculation model to obtain mixed electric field intensity when the high-voltage alternating current / direct current is parallel, and changing the height and the parallel interval of the circuit; and obtaining an optimal mixed electric field environment. When the method is implemented, the high-voltage alternating current / direct current parallel line mixed electric field can be predicted, the height and the interval distance of the high-voltage alternating current / direct circuit can be analyzed and regulated so as to lower the mixed electric field intensity of the high-voltage alternating current / direct current power transmission circuit, and a purpose that the electromagnetic environment of the high-voltage alternating current / direct current parallel line is optimized is achieved.

The invention discloses synthetic aperture radar simulation in a high-frequency approximation method based on electromagnetic scattering. According to radar, firstly a needed radar parameter is chosen, and then the radar parameter is distributed to different modules for position analysis, scattering electric field calculation, emitted signal production and echo generation processing. A synthetic aperture radar is simulated from the electromagnetic angle, and a method of synthetic aperture radar echo simulation is improved. According to the synthetic aperture radar simulation, a complex electromagnetic scattering principle is introduced to the synthetic aperture radar echo simulation, the problem that in a traditional method, mutual coupling between electromagnetic sources inside a target is neglected is solved, an obtaining process of synthetic aperture radar echo data is simulated from an overall perspective, operation quantities are greatly reduced, efficiency of an echo simulation process is improved, and results of the echo simulation approximate real situations.

The invention provides a UHVDC (Ultra High Voltage Direct Current) line ground three-dimensional composite electric field calculation method capable of considering terrain influence. The method comprises the following steps: S1: firstly, simplifying a complex terrain into an undulant three-dimensional ground, and establishing a three-dimensional composite electric field calculation model; S2: selecting any one calculation point on the ground, and utilizing a three-dimensional nominal electric field obtained by a moment method to determine an electric line of force from the point back to the surface of a lead; S3: setting an electric charge density initial value of the surface of a transmission lead, and obtaining the electric charge density and the nominal function of each point from the surface of the transmission lead along the space of the electric line of force; S4: updating the electric charge density of the surface of the lead until an average value of the spatial electric charge density meets a limitation condition; and S5: according to the obtained electric charge density and the nominal function, calculating a three-dimensional composite electric field on a complex ground. The method is based on a Deutecsh hypothesis principle and is combined with the moment method, influence on the three-dimensional composite electric field by the complex terrain is considered in a calculation process, and electromagnetic environment evaluation carried out when a UHVDC transmission line goes through the complex terrain can be realized.

The invention discloses a computation method of a surface synthesis electric field of a small grounding object under a DC (direct current) power transmission line, belonging to the technical field of electromagnetic environment analysis of extra-high voltage and ultra-high voltage DC power transmission lines. The computation method comprises the following steps that: when the small grounding object does not exist under the DC power transmission line, a two-dimensional ion flow field computation method is used for computing the charge density of each point in the space; and when the small grounding object exists under the DC power transmission line, a three-dimensional electrostatic field computation method is used for acquiring the surface synthesis electric field of the object according to the charge density of each point in the space in the two-dimensional ion flow field computation result. The method disclosed by the invention reduces the computation complexity on the premise of ensuring the accuracy of the computation result.

A disclosed specific absorption rate measurement system according to an embodiment of the present invention measures a specific absorption rate of electromagnetic waves from a radiating source absorbed in a dielectric medium. The system includes a measurement portion that measures a first electric field vector on an observation surface which is a two-dimensional surface in the dielectric medium; an electric field calculation portion that calculates a second electric field vector in a point excluded from the observation surface in accordance with electric field components of the first electric field vector measured on the observation surface, the electric field components being parallel to the observation surface; and a calculation portion that calculates the specific absorption rate from the calculated second electric field vector.

A mechanical property testing device and method for reliably measuring strain and fatigue characteristics of material specimens is described. An input electrical signal is applied to create an electric field around a first piezoelectric member. The resultant deformation of the first piezoelectric member transfers a force to the specimen being tested which transfers a force to a second piezoelectric member causing deformation. The deformation of the second piezoelectric member generates an output electrical field which is measured. The stress state of the specimen is calculated from fundamental material constants and the measured output electrical field.

The invention discloses a GIS equipment low-voltage conductor surface electric field intensity measurement method which belongs to the technical field of conductor surface electric field measurement. The structure of an electric field intensity measurement device is that a GIS equipment housing is fixed on a pedestal through a short support, a high-voltage conductor is supported in the center of the GIS equipment housing through a long support on the pedestal, and a wedge block is cut in the middle of the housing and is supported in situ with insulating material; the wedge block is connected with a resistor of 10 kilo ohms, the resistor is connected to the ground, and two ends of the resistor are connected with an amplifier circuit; the amplifier circuit is connected with a display; electric field intensity measurement is that high-voltage electricity of alternating current 220kV is applied to the high-voltage conductor, voltage signals of the two ends of the resistor are input to the amplifier circuit through a cable, and the reading of the electric field intensity is displayed on the display. Through electric field calculation and analysis of internal defects of GIS equipment, and through verification by a test, the GIS equipment low-voltage conductor surface electric field intensity measurement structure is of great significance to improving the internal insulating strength of the GIS and researching a relation between the internal defects and electric field intensity of the GIS equipment.

Disclosed herein is a three dimensional small bin electromagnetic consecutive array data acquisition method used in oil exploration comprising the steps of recording data using small bin lattices on execution of arrangement electrodes, each acquisition station (Ex, Ey) records the natural electromagnetic field time series data with the same acquisition parameter simultaneously; interference is removed first, for recorded data processing to get interference-free data; for border points and center point, the recording point serves as center point, and the same component from adjacent two points to total points area added together to obtain the average value of electric field data at time domain for each observation point; for corner points, the average values of the same electric field component from adjacent two points to total survey points toward bin direction is calculated; the electric field components acquired in maximum space serve as the new electric field values respectively; new time series data acquired in which the noise and the static shift effect have been suppressed, and apparent resistivity and phase curves of each point are acquired after processing with conventional method.

The invention discloses a local discharging detection method of an insulating draw bar based on electric field calculation and X-ray excitation. The method comprises the following steps: firstly, applying 1.7-time rated voltage to two ends of a to-be-detected insulating draw bar for one minute, then reducing the voltage to 1.3-time phase voltage, and detecting the local discharging; determining that the insulating draw bar is unqualified if the local discharging is detected; maintaining the voltage if no local discharging is detected, and performing X-ray scanning on the insulating draw bar from a grounding end of the insulating draw bar from bottom to top by virtue of an X-ray generator; and detecting the local discharging when the X-ray scanning is performed on one position, wherein if the local discharging disappears when the X-ray leaves the position, the insulating bar has a defect on the position, and if no local discharging is detected in the whole process, the insulating draw bar is qualified. Different positions of the insulating draw bar are irradiated by X rays with reasonable intensity, so that the problem that the defect on the position with a low electric field cannot be detected due to non-uniformity of the distribution of the electric field can be solved.

The invention discloses a method and a system for establishing a wind power plant model, and a wake value calculation method and a wake value calculation system. The establishment method comprises thesteps of obtaining environment wind speed data of a plurality of detection positions in a wind power plant calculation domain; calculating incoming flow wind speed data which are not affected by wakeflow at any position in the wind power plant calculation domain according to the environment wind speed data; establishing a Jensen wake model based on Gaussian distribution; processing the incomingflow wind speed data according to the Jensen wake flow model to calculate wake flow wind speed data; training a machine learning model by taking incoming flow wind speed data and wake flow wind speeddata as training samples to obtain a wind power plant model; the wind power plant model is used for predicting wake flow wind speed data according to the environment wind speed data. Accurate and rapid prediction of wake flow speeds under different environmental wind speeds is achieved, compared with a three-dimensional CFD model, grids at an impeller do not need to be divided, the number of the grids is greatly reduced, the calculation time is shortened, and the calculation efficiency is improved.

The invention discloses an antenna near-field measurement method using an interpolation algorithm. The method comprises the steps: S10, collecting and recording electric field amplitude and phase information on a near-field scanning surface of the antenna to be measured, wherein the near-field scanning surface is in any curved surface shape and needs to meet the following three conditions at the same time. S20, interpolating the electric field amplitude on the near-field scanning surface of the antenna to be measured through cubic spline interpolation. S30, interpolating the electric field phase on the near-field scanning surface of the antenna to be measured through bilinear interpolation. S40, calculating a far-field electric field of the to-be-tested antenna according to a Huygens equivalence principle based on the near-field electric field amplitude and phase value of the to-be-tested antenna obtained by interpolation. and S50, based on the calculated far-field electric field of the to-be-tested antenna, calculating a far-field normalized directional diagram of the to-be-tested antenna. The near-field scanning surface in the method is not limited to a plane, a cylindrical surface and a spherical surface, and can be changed into any curved surface according to the actual measurement environment change.

The invention discloses an electric field calculation method for multiple coupled electric fields in a spatial high voltage part. The electric field calculation method for multiple coupled electric fields in the spatial high voltage part comprises steps of adopting a finite element difference method to determine conditions of charge deposition distribution and internal charge conduction of spatial high energy electrons in the high voltage part, setting a boundary condition according to a working voltage condition of a high voltage part, substituting a charge deposition amount and a conduction amount into a current conduction function to calculation spatial charge distribution, substituting spatial electrons into a poisson's equation, calculating to obtain a coupled electric field between an electric field produced by the spatial high energy electrons depositing in the high voltage part and an electric field produced by working voltage to obtain a distorted position of the two electric fields. The electric field calculation method for multiple coupled electric fields in the spatial high voltage part considers an affect of the working voltage on a charge-discharge effect, can improve accuracy of the electric field calculation, and provides basis to accurately evaluating the risk introduced by the charge-discharge effect of the spatial high voltage part and effectively guiding a design for protecting the high voltage part charge-discharge effect.

The invention relates to a simulation calculation method for a combined gap impulse discharge development process. The method comprises the following steps: step 1, establishing an electric field calculation physical model considering charged particle motion in the combined gap impulse discharge development process in finite element software; step 2, determining the potential of a potential suspension conductor in each discharge development stage by combining an electric field calculation result and a charged particle motion simulation result in a pre-discharge stage; and step 3, realizing simulation of a combined gap breakdown development process by taking a condition that the streamer with a relatively low development speed reaches the surface of the potential suspension conductor as a breakdown criterion. According to the method, the actual physical process of the combined gap discharge process can be analyzed, and the discharge mechanism of the combined gap discharge process can bedetermined.

The invention relates to a method for acquiring the electric field distribution of a large-sized complex aircraft by using a fast boundary element method, which is technically characterized by solving the problem of the fast computation and analysis of a large-sized electrostatic field of the aircraft in the field of aircraft design by adopting the boundary element method. The method comprises the following steps of: dividing a medium interface into smooth curved surfaces with parametric equations by adopting a Nessler discretization method, and projecting integral points to the medium interface to form boundary integral points through the parametric equations; and constructing a wavelet transform matrix on the basis of the multiscale grouping of the integral points, and carrying out matrix compression, computation and storage on a boundary element coefficient matrix. The invention overcomes the shortages of complex computation, large computation amount and low precision of the coefficient matrix in the traditional wavelet boundary element method and effectively reduces the internal storage occupying amount and the computation time of boundary element analysis, thereby solving theproblems of a large-scale project with millions of freedom degrees; and in addition, the invention can be applied to the electric field computation and analysis of the large-sized complex aircraft inan aerospace field and electric field analysis in other project fields.

The present invention provides an extra-high voltage alternating current circuit basket method equipotential operating path planning method by taking the considering environmental factors. Meteorological parameters of a geographic position where an extra-high voltage alternating current circuit hot-line work tower is located to obtain an air humidity H, an environment temperature T and the currentair pressure P when operation is performed, and on this basis, the air relative dielectric constant is obtained; the position of an equipotential worker in the basket is preliminarily determined through the determination of the operating rope length and the determination of the combined gaps to perform electric field calculation for the human body surface field intensity of each operating track point; the human body surface field intensity of each operating point is compared to a critical corona field intensity of a wire to finally determine ten operating track points, and the ten operating track points meeting requirements are connected to form an arc to obtain an extra-high voltage alternating current circuit basket method equipotential operating path. The method provided by the invention considers the operating tower environmental factors, and the basket method equipotential operating path planned for the extra-high voltage alternating current circuit provides theoretical basis andguidance for the safety operation of the hot-line work.

The invention provides a method and system for calculating the full-time apparent resistivity of a time-domain transient horizontal electric field. The method includes obtaining field acquired time-domain recording data including two electric fields mutually perpendicular to each other and Ry(t), carrying out time-domain filtering, superposing and eliminating flying spots for the time-domain recording data obtained in the previous step, calculating the complete waveforms of upper and low steps, calculating the electric fields of the upper and low steps on phi direction, and calculating the full-time apparent resistivity Pw(t) through the electric field of the upper step.

The invention discloses an electric field calculation APP for a big motor stator line rod end part model. A method comprises the steps of 1, performing parameterization modeling on the end part of a big motor end part (the parameterization control on the end part wire core cross section dimension, the three-dimensional twisting angle of an end model, the thickness of an insulation layer and an anti-halation layer, and the length of each section of the three-section type anti-halation layer is realized); 2, performing finite element numerical simulation analysis on the model built through parameterization; adding corresponding materials on the model; performing mesh generation; using a frequency domain solver at 50hz for electric field calculation; solving the corresponding electric potential and electric field and the consumed distribution diagram; 3, building an end electric field finite element calculation APP according to the process; performing end part anti-halation layer electric field and electric potential and loss solving through changing the dimension parameter, the material parameter and the test parameter of a model. The electric field calculation APP has the advantages that the time consumed by development personnel in the modeling and simulation process can be effectively saved; the design efficiency is effectively improved.