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 an impedance simulation method for a chip capacitor in a power-supply distribution network. The problem that the capacitor impedance is unknown and accordingly the usage is influenced is mainly solved. The impedance simulation method comprises the steps of 1 manufacturing a capacitor clamp and a calibration part; 2 using a general standard part and an electrical characteristic file of the general standard part to calibrate a vector network analyzer, measuring the electrical characteristics of the manufactured standard part and saving the electrical characteristic file; 3 using the manufactured standard part and the electrical characteristic file to calibrate a vector network analyzer and measuring a scattering parameter of the capacitor; 4 converting a reverse transmission coefficient obtained through measurement into a total impedance parameter and removing installation inductive impedance to obtain the capacitor impedance; 5 adopting a vector fitting method to performing fitting on the capacitor impedance so as to obtain a high-order expression; 6 calculating the high-order expression to obtain impedance and obtaining the impedance of the capacitor with no tag parameters. The impedance simulation method achieves accurate capacitor impedance simulation, is simple and quick and can be used for obtaining an impedance parameter of the capacitor.

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 provides a method and equipment for debugging a microwave cavity filter, and a storage device. According to the method, a polynomial coefficient of an acquired dissipation parameter S isobtained through a vector fitting method, and then the dissipation parameter S is restored through the polynomial coefficient to obtain smooth and noiseless Smea; Sobj is obtained through a generalized Chebyshev integrated design method, and a difference function F between the Smea and the Sobj is calculated; and according to the sequence of screws, each screw is debugged in sequence, and when the F is the minimum, the next screw is replaced in sequence, and the finally output dissipation parameter meets a design index. The equipment for debugging the microwave cavity filter and the storage device are used for implementing the method for debugging the microwave cavity filter. The method for debugging the microwave cavity filter provided by the invention has the following beneficial effects: the method can be applied to the debugging of a cross-coupled filter, a model does not need to be established, and influences of phase offset and the like do not need to be removed, thus the debugging process is simple and rapid, the debugging time is shortened, and the debugging efficiency is improved.

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 method for establishing an equivalent model of a wind farm. The method comprises a step of establishing a sweep frequency module and an excitation source main circuit on the Draft of an RTDS simulation platform, a step of establishing the detailed model of a power grid and setting the power supply in the power grid to be zero, a step of writing a batch processing script in the Runtime of the RTDS simulation platform, and changing the output value of a controlled voltage source in the Draft in real time, displaying sweep frequency voltage and current in a specific image, and storing data into a specified folder, a step of calculating an admittance value under each frequency according to sweep frequency voltage and current data, and the fitting phase-to-ground admittance and mutual admittance as a rational function in Matlab by using a vector fitting function, and a step of storing the rational function obtained through fitting into the specified folder with a certain format. The equivalent model established by using the above method can accurately restore the electromagnetic transient response of the wind farm, and thus a foundation is laid for the study of the electromagnetic transient characteristics of a wind farm access power grid.

The invention discloses an indoor positioning method adopting multichannel vector fitting. The method comprises the following steps: before establishing a database, setting a positioning network (lattice position distribution) and a signal monitor position in a positioning area as required, establishing an RSS (Received Signal Strength) database including a signal strength database and a position information database by using RSS data acquired from each signal channel and different positions by a plurality of signal monitors, and establishing an SSD (Signal Strength Difference) database by using the RSS database; at a real-time indoor positioning stage, optionally selecting a point (target) to be positioned from the positioning area, monitoring the RSS data of the point, calculating target SSD data by using these RSS data, matching the target SSD data with a comprehensive SSD database, picking up most-matched SSD data in the database, and determining a target position. The indoor positioning method has the effect of accurately positioning signal sources in a positioning field in real time.

The invention discloses a laser cutting machine and an energy control system of a laser cutting multilayer composite material. The energy control system is in data connection with a speed / position adjuster and a servo driver of a laser cutting head, and comprises a speed / position feedback data reading circuit, a DSP core circuit, a PWM output control circuit and a serial port communication module; the DSP core circuit is in double-direction data connection with the speed / position feedback data reading circuit, the PWM output control circuit and the serial port communication module; encoder signals fed back by the servo driver serve as speed fitting real-time data, and are fed back to the speed / position adjuster, speed data fed back by the laser cutting head in real time are read in real time, and the actual running speed of a current laser cutting head is fitted out; and due to the adoption of the speed vector fitting concept, real-time feedback of track speed is achieved, the control error is reduced, the laser output energy is precisely controlled, and cutting quality of pixel corners is improved.

The invention discloses a modeling and intelligent design method of a micro-strip direct coupling filter. The method comprises the following steps: acquiring an S parameter of an initial filter; calculating de-phase loading factors alpha and beta by adopting an optimization algorithm; obtaining a pole P and a residue R through vector fitting calculation; carrying out full-standard coupling matrixsynthesis to obtain a filter coupling matrix M; adopting numerical iteration decoupling transformation to obtain a decoupling matrix Md meeting a decoupling transformation condition; determining design sizes of multiple groups of filters, obtaining S parameters of the filters based on measurement or electromagnetic simulation, extracting a decoupling matrix according to the steps, and establishinga space mapping model of the design sizes and the decoupling matrix; adjusting decoupling matrix elements of the initially designed filter through an optimization algorithm according to the expecteddesign value to obtain a decoupling matrix M<d-opt> of a filter coupling matrix close to the expected design value; and calculating a design parameter L according to the decoupling matrix M<d-opt> byutilizing the space mapping model.

The invention relates to a propagation matrix modulus optimization fitting method and system based on a differential evolution algorithm. The propagation matrix modulus optimization fitting method comprises the steps of: determining target fitting precision tol and a fitting frequency range; determining a pole number range; determining the range of the delay [tau]; determining the maximum value ofa delay coding vector based on the range of the delay [tau]; determining the maximum value of a pole number encoding vector based on the range of the pole number; determining the number of solutionsto be N; initializing related parameters in an iteration process; performing iterative computation based on the related parameters; reading the solution x* with the minimum [delta] in the group to obtain the number and delay of poles contained in the solution x*, and executing the above steps to obtain a new pole; and fitting the modulus of the propagation function matrix by using a vector fittingtechnology according to the pole number, the time delay and the new pole obtained in the previous step, calculating a fitting error, and outputting a fitting result and the fitting error. According to the method, the differential evolution algorithm is introduced, the nonlinear optimization problem can be well solved, and the efficiency is improved.

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 tracing-vector hierarchical storage mechanism for internet-of-things perception data. The storage of the internet-of-things perception big data is divided into two layers: a tracing storage layer and a vector storage layer. In the tracing storage layer, a simple and quick storage method is adopted for realizing efficient storage of original sampling data, and vector data is uploaded to the vector storage layer through vector fitting and updating policies. In the vector storage layer, through a vector sequence-based perception big data storage model and query and analysis methods, efficient processing of the perception big data is realized. A vector is defined as a state change mode of a monitored object; and a state of the internet-of-things monitored object lasts for a relatively long time according to a law generally, and the state, lasting for the relatively long time, of the monitored object can be described by using the vector, so that while the data precision is ensured, the data updating and storage costs of the vector storage layer are greatly reduced.

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 discloses a vector fitting model order reduction method based on error control in a linear system. Specific to the conventional vector fitting, the order of a constructed pole-residue model is always very high under a wide frequency band, particularly in a highly-dynamic linear system with a resonance point. An error control function is introduced, data including important features of the linear system are selected in a continuous iteration way, and certain slightly-varied data representing details are neglected, so that the order of the constructed model is effectively reduced under the condition of sacrificing certain modeling accuracy. A low-order pole-residue macro model is obtained under the condition that the modeling accuracy requirement is met. The pole-residue macro model is further transformed into a state space model, passive processing is performed, and the constructed pole-residue macro model is output lastly. By adopting the vector fitting model order reduction method, the balance between model accuracy and complexity is realized, and the simulation efficiency of electromagnetically-compatible electromagnetic emission is increased.

The invention provides a vector fitting and balanced truncation method based electromagnetic compatible macro model modeling method. The vector fitting and balanced truncation method based electromagnetic compatible macro model modeling method comprises measuring port scattering parameters to obtain scattering parameters under different frequency points and obtaining a state space model due to conversion through a vector fitting method; constructing a passivity judgment matrix according to a state equation coefficient matrix and performing model passivity judgment and enhancement; calculating controllability and observability Grammian matrixes according to the state equation coefficient matrix to achieve system balance; calculating an HSV (Hankel Singular Value) and a corresponding curvature spectrum of every frequency point and confirming orders of a reduced-order model; confirming a reduced order macro module; obtaining a general module. According to the vector fitting and the balanced truncation method based electromagnetic compatible macro model modeling method, a wideband system model of an original circuit can be fit only according to testing data within a small frequency band, the accuracy is high, the fitting time is short, the model orders can be confirmed rapidly after order reduction, the electromagnetic compatible macro model modeling time is greatly reduced, and a converted SPICE (Simulation Program with Integrated Circuit Emphasis) net list has universality.

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 modeling and intelligent design method of a micro-strip direct coupling filter. The method comprises the following steps: acquiring an S parameter of an initial filter; calculating de-phase loading factors alpha and beta by adopting an optimization algorithm; obtaining a pole P and a residue R through vector fitting calculation; carrying out full-standard coupling matrixsynthesis to obtain a filter coupling matrix M; adopting numerical iteration decoupling transformation to obtain a decoupling matrix Md meeting a decoupling transformation condition; determining design sizes of multiple groups of filters, obtaining S parameters of the filters based on measurement or electromagnetic simulation, extracting a decoupling matrix according to the steps, and establishinga space mapping model of the design sizes and the decoupling matrix; adjusting decoupling matrix elements of the initially designed filter through an optimization algorithm according to the expecteddesign value to obtain a decoupling matrix Md-opt of a filter coupling matrix close to the expected design value; and calculating a design parameter L according to the decoupling matrix Md-opt by utilizing the space mapping model.

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.

Disclosed is a rapid and accurate prediction method of the ultra wide band electromagnetic pulse response of a wide-band antenna. The method comprises the following steps of 1) utilizing a wide band antenna field-circuit conversion transmission function to express the relation between an ultra wide band electromagnetic pulse environment and the time domain response, namely, the sensing open-circuit voltage of the output end of the wide-band antenna and obtaining the frequency domain amplitude phase response curve of the wide-band antenna; 2) utilizing a vector fitting method to determine the frequency domain response of the wide band antenna field-circuit conversion transmission function; 3) further obtaining the time domain impact response of the wide band antenna field-circuit conversion transmission function; 4) by computing the time domain impact response of the wide band antenna field-circuit conversion transmission function and the convolution of the time domain expression of the ultra wide band electromagnetic pulse environment, obtaining the time domain response of the output end of the wide-band antenna under the action of ultra wide band electromagnetic pulse. The rapid and accurate prediction method of the ultra wide band electromagnetic pulse response of the wide-band antenna has the advantages of, compared with conventional fall-wave numerical predication methods, omitting computation of antenna response frequency point by frequency point, being capable of computing the time domain response of the output end of the wide-band antenna in one step and accordingly being high in computing speed and accurate in results.

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.

The invention discloses an Hspice compatible equivalent circuit simulation system and method. The system comprises a data acquisition module, a parameter check module, a function generation module and an equivalent circuit generation module, wherein the data acquisition module is used for reading a multi-port circuit system data file in a Touchshone format from a data storage unit of a computer, and obtaining an S parameter matrix from the multi-port circuit system data file; the parameter check module is used for checking whether all S parameters in the S parameter matrix meet the circuit passive characteristic; the function generation module is used for setting extremum-residual value quantity required by a rational number function generating the S parameters, and system errors; and the equivalent circuit generation module is used for generating a rational number function matrix of the S parameters by using an extremum-residual value quantity-based executing vector fitting algorithm, and simulating and synthesizing the Hspice compatible equivalent circuit according to the rational number function matrix. By implementing the invention, the Hspice compatible equivalent circuit can be generated by using multi-port system data, thus the circuit simulation efficiency is increased and the problem of convergence of a simulation circuit can be solved.

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 variable-frequency power transmission line modeling method which includes the following steps that a fitness function of iteration poles is built, and selection, crossing and mutation genetic operation are carried out on iteration pole groups occurring in the vector fitting process; the optimal pole is found through global optimization capacity of a genetic algorithm, the optimal pole is applied to a vector fitting method for optimizing guide of an optimization direction, and an approximate rational expression with globally optimal characteristic admittance and a delay function is obtained. The variable-frequency power transmission line modeling method combines the vector fitting method with the genetic algorithm, does not perform pure slow optimization by means of the genetic algorithm, but performs timely rewrite of population individuals according to the rational expression form of the vector fitting method, aims to achieve quick iterative convergence, and greatly increases optimization speed.

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 discloses a nondestructive evaluation method for the high-frequency electrical parameters of a power transmission cable and the accessories, which comprises a vector fitting process anda parameter optimization process, and specifically comprises the following steps of S1, carrying out vector fitting on a frequency domain model of the cable, and providing a lumped parameter equivalent circuit model to obtain parameters of a circuit model to be optimized; and S2, during a parameter optimization process, firstly injecting an excitation pulse source at the head end of the cable to obtain an experimental measurement waveform, and secondly, optimizing the circuit model parameters preliminarily proposed in the step S1 by adopting a simulated annealing algorithm in combination withthe experimental measurement waveform to realize the multi-parameter identification. According to the present invention, by adopting a series of algorithms and technologies of nondestructive pulse signal excitation, high-frequency circuit modeling and analysis and circuit element multi-parameter identification, the nondestructive evaluation of the high-frequency electrical parameters of the powertransmission cable and the accessories is achieved, and the method has important significance for accurately evaluating the changes of time and amplitude of a traveling wave head and improving the positioning precision.

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.