86 results about "Vector fitting" patented technology

The invention relates to a method for estimating electromagnetic interference of a power electronic conversion system based on a power transmission line. The method comprises the steps of enabling thepower transmission line between a power electronic conversion device and a power system to be equivalent to a transmission circuit; establishing a physical structure of wideband equivalent resistance-inductance steplike topology of the power transmission line; accurately identifying and optimizing wideband key parasitic parameters of the resistance-inductance steplike topology of the transmissionline based on a vector fitting iteration strategy; and substituting the calculated key parasitic parameter values of the resistance-inductance steplike topology into the transmission circuit and estimating a difference mode/common mode conducted electromagnetic interference level of the power electronic conversion system. According to the method, the numerical equivalence is performed on the basis of a resistance-inductance steplike topology theory, so that the frequency change transmission characteristic of inherent parameters of a cable is represented, accurate approximation and stable convergence of a prediction model are achieved, and an effective theoretical basis is provided for achieving accurate identification of wideband parasitic parameters of the model and EMC design of the power electronic conversion system.

The invention relates to a method of generating frequency dependence network equivalence based on an integral vector fitting process, and belongs to the technical field of dispatching automation of electric power system and power grid emulation. The method comprises calculating a sampling value of network frequency characteristics based on a simplified model method, calculating any element of frequency dependent network equivalent (FDNE) according to the sampling value of the frequency characteristics based on a vector fitting process, and generating the FDNE by adopting the integral vector fitting process. The method of generating the frequency dependence network equivalence based on the integral vector fitting process has the advantages of being high in efficiency, accurate and practical, is convenient to achieve in a time domain, is directly applied to electromagnetic transient emulation and is satisfying in engineering practice effect.

The invention discloses a measurement-based modeling method by prediction on an electromagnetic emission broadband behavioral level of an electronic component. The method comprises the following steps of: firstly carrying out active and passive judgments on a measured object, thus acquiring a port scattering parameter of the measured object; then performing vector fitting algorithm on the mapped port scattering parameter to acquire a state space model; and then converting the state space model into an SPICE (Simulation Program with Integrated Circuit Emphasis) circuit to be finally applied to circuit simulation. According to the invention, the modeling method by the prediction on the behavioral level can accurately establish an equivalent broadband model of the complicated electronic component by measuring data within a certain bandwidth or under fewer sampling points without relying on a simulation model provided by an electronic component manufacturer, and can achieve electromagnetic emission simulation on the circuit.

The invention relates to a plane normal vector measurement method based on a laser tracker, and belongs to the technical field of digital measurement. The object of the invention is to improve the measurement accuracy of the prior art, and to provide a method for measuring a plane normal vector at high precision. The laser tracker is a high-precision and large-scale measuring instrument, operatesin a spherical coordinate system with a tracking head as the origin, and measures the position and posture of a measured object in cooperation with a target ball. The plane normal vector measurement method can be applied to the fields of positioning and installation of large components, machine tool calibration and the like. In combination with a characteristic that the laser tracker has high measurement precision along a light direction and the characteristic that the vertical plane direction error in the plane normal vector fitting has the greatest influence on the plane normal vector fitting precision, a laser tracker measurement light is close to be parallel with the plane normal vector direction by visual adjustment before the measurement, which improves the measurement accuracy of the plane normal vector.

The embodiment of the invention is suitable for the technical field of medical examination and inspection instruments and services, and provides a wireless capsule endoscope positioning method and apparatus, and terminal equipment. The method comprises the following steps: activating a sensor sub-array from a magnetic sensor array when an in-vitro driver is used for driving a wireless capsule to move; measuring a magnetic field by the sensor sub-array to obtain current magnetic field data; calculating a current five-dimensional pose of the wireless capsule based on the magnetic field data, wherein the five-dimensional pose comprises three-dimensional positions and two-dimensional magnetic moment directions of the wireless capsule; and carrying out normal vector fitting on the two-dimensional magnetic moment directions to obtain a sixth-dimensional pose of the wireless capsule, wherein the five-dimensional pose and the sixth-dimensional pose jointly form a positioning pose of the wireless capsule. By adopting the method to position the wireless capsule endoscope, certain positioning precision can be maintained while the positioning updating frequency is increased.

The invention discloses a transient traveling wave time domain calculating method of a same-tower double-circuit DC power transmission line. The method includes the following steps of calculating the series impedance matrix Z and the parallel impedance matrix Y of the line at different frequencies, the eigenvector matrixes TU, TI of the matrixes ZY and YZ, and an eigenvalue matrix Lambda; calculating the vector wave impedance matrix Zc-phase and the sequential wave impedance matrix Zc-phase-r according to the matrixes Y, TI, and Lambda; performing vector fitting on the matrixes TU, TI, TU-1, and TI-1 to obtain TU-r, TI-r, TU-r-1, and TI-r-1; performing vector fitting on the propagation coefficients exp (-gamma Mm) of the forward wave of different moduli to obtain a sequential propagation coefficient matrix Hm-r of the corresponding m mold; determining the fault type according to the circuit structure of the fault points to write the boundary equation; and calculating the line fault transient electrical amount. The method takes into account the influence of the frequency variation of the line parameters, and solves the problem of the line decoupling caused by the unbalanced same-tower double-circuit DC line.

The invention discloses a general simulation program with integrated circuit emphasis (SPICE) equivalent circuit simulation system and a general SPICE equivalent circuit simulation method. The system comprises a data reading module, a matrix conversion module, a parameter selection module and an equivalent circuit generating module, wherein the data reading module is used for reading a data file of a Tabular W-element format from storage equipment and acquiring an RLGC transmission line matrix from the data file by using an internal difference algorithm; the matrix conversion module is used for converting the transmission line matrix into an ABCD parameter matrix and converting the ABCD parameter matrix into an S parameter matrix; the parameter selection module is used for selecting an S parameter frequency range by using the internal difference algorithm and selecting a pole-residue number required by a vector fitting algorithm; and the equivalent circuit generating module is used for executing the vector fitting algorithm based on the pole-residue number to generate a rational number function matrix corresponding to the S parameter matrix and generating a corresponding equivalent circuit according to the rational number function matrix. By implementing the system and the method, the data file of the Tabular W-element format is imported into the simulation equivalent circuit under simulation software of an SPICE format.

The invention discloses a method and a system for inhibiting a residue pole ratio in an overhead line frequency domain propagation matrix vector fitting process. The method comprises the following steps: for each element, when a corresponding initial residue pole ratio is greater than a first preset threshold, performing singular value decomposition on a coefficient matrix, and setting a singularvalue of a product of a maximum singular value in a first singular value matrix and a preset precision threshold to be zero to obtain a second singular value matrix; determining an updated coefficientmatrix by using the second singular value matrix, and determining a new residue vector by using a least square method; removing a pole with a value of 0; judging whether the ratio of the residue corresponding to each of the remaining poles to the pole is smaller than a first preset threshold value or not; if so, indicating that the suppression is successful, and determining a frequency domain propagation matrix for expressing each element in a rational mode by utilizing the residual poles and the corresponding residues so as to ensure the stability of time domain simulation; otherwise, indicating that the suppression fails, and carrying out recalculating.

The invention relates to a passive-modeling-based circuit simulation method and belongs to the technical field of integrated circuit design. Firstly, an electromagnetic simulation method is adopted to generate a data file, and an initial simulation mode is built with the aid of a vector fitting method according to the data file; the initial simulation model is modified and changed to an initial passive model; the precision of a final passive model serves as an optimization target, a passive restriction serves as an optimization constraint condition, the initial passive model serves as the initial solution, and the finial passive model is obtained through an optimization algorithm; and the coefficient matrix of the final passive model is inputted to a circuit simulator, and the circuit parameter is obtained through calculation. The circuit simulation method provided by the invention improves the modeling precision, shortens the modeling time, improves the efficiency and precision of circuit simulation, and enhances the astringency of the circuit simulation. The circuit simulation method can be applied to the design of the integrated circuit, improves the reliability of the circuit simulation and the efficiency of the circuit design, and shortens the time of the circuit product to the market.

The invention discloses a passivity correction method for an integrated circuit system. The passivity correction method comprises the steps that the frequency response of each pole under each frequency, which is output by S parameter vector fitting, is calculated; according to the frequency response of each pole, determining a reduced residue gradient vector corresponding to each frequency; according to the residue gradient vector, determining a quadratic term matrix corresponding to the full frequency of each frequency; and performing Kronecker product operation on the full-frequency quadratic term matrix to determine a final quadratic term matrix. According to the method, the dimensionality of the matrix in the operation process is reduced, the operation amount is greatly reduced, the operation time is shortened, and the calculation efficiency of the quadratic term matrix is improved.

The invention discloses a method for carrying out data correction by utilizing vector fitting. The method comprises the following steps of setting a given original data set as a vector fitting object; establishing a data set of vector fitting, performing primary iteration of vector fitting, and generating a new data set after iteration; and judging whether the new data set meets a convergence condition or not, and when the convergence condition is met, outputting a result that the new data set is subjected to causality correction. According to the method for correcting the data by using the vector fitting, the corrected data can meet causality, and the passivity of the data can be ensured by subsequently adopting the standard passivity correction.

A simulation system for producing equivalent circuits reads data corresponding to a tabular W element format in a storage device, and adds data of the tabular W element format file using interpolation algorithm. A frequency-dependent transmission matrix is transformed into an N-port network matrix describing electrical properties of a multi-input and multi-output network. An N-port network matrix is transformed into a S-parameter matrix. A range of frequency of a s-parameter is determined and numbers of pole-residue, times for recursion and durable maximum system errors in the equivalent circuit is also determined. A a vector fitting algorithm is performed and a rational function matrix composed with s-parameters is produced, to produce a general SPICE equivalent circuit based on the generated rational function matrix.

A simulation system and method for generating equivalent circuits compatible with HSPICE reads data corresponding to N-port network system format in a storage device, and obtains S-parameter matrixes from the N-port network system. S-parameters in the S-parameter matrix that satisfy passivity are checked, and an interpolation algorithm to supplement S-parameters with passivity when some S-parameters not satisfy passivity is performed. Numbers of pole-residue, times for recursion and a tolerant system error of a rational function are generated for determining S-parameters. A rational function matrix composed of S-parameters is generated by performing a vector fitting algorithm, and an equivalent circuit is generated compatible with HSPICE format based on the generated rational function matrix.

The invention discloses a water gun head tracing cooling method based on a water and fire plate bending machine. The method comprises the following steps that a coordinate system is built on the surface of a workpiece, and the preset flame way track curved line of a fire gun head is obtained; the preset flame way track curved line is subjected to vector fitting in the movement direction through n fold lines, and the included angle between the vectors of the k fold line and the (k+1) fold line is measured to be theta k; when the fire gun head moves to the starting point of the vector of the (k+1) fold line, a water gun head revolved by the angle theta k around the fire gun head, and the vectors of the link line of the water gun head and the fire gun head and the (k+1) fold line are in collineation, wherein n and k are both positive integers, and kmax+1=n. Therefore, the movement track of the water gun head infinitely approximates to the movement track of the fire gun head, so that the flame way machining track and the cooling liquid falling point track nearly coincide, the cooling position accuracy and the cooling effect of the water gun head are greatly improved, and meanwhile, the surface machining quality of boards are improved. The invention further discloses a water gun head tracing cooling system and the water and fire plate bending machine, and the water gun head tracing cooling system and the water and fire plate bending machine have the above beneficial effects.

The invention provides a photovoltaic inverter parameter identification method and device based on port impedance characteristics, and the method comprises the steps: determining an admittance matrix model of a photovoltaic inverter in a dq coordinate system according to a controller structure, a filter structure and electrical parameters of the photovoltaic inverter; obtaining admittance data of an AC side port of the photovoltaic inverter under multiple frequencies, and performing accurate vector fitting on each frequency and the corresponding admittance data to obtain a fitting transfer function; and according to the fitting transfer function, calculating the elements in the first row and the second column of the admittance matrix model to obtain an identification result of the to-be-identified parameter. According to the method, accurate controller parameter identification is realized through impedance characteristics, an accurate and feasible method is provided for photovoltaic inverter parameter identification, and the accurate controller parameters can be obtained through external characteristics of the photovoltaic inverter to help to analyze the grid connection process of the photovoltaic power generation system.