16 results about "Transmission line parameters" patented technology

The invention belongs to the field of power transmission line parameter measurement, and discloses a live-line testing device and method for mutual inductance line parameters and zero-sequence impedance parameters. The device comprises a double-circuit line simulation module, a pilot frequency excitation module, a power frequency simulation module, a synchronous acquisition module and a signal processing module. The isolation transformer simulates a double-circuit line, the pilot-frequency power supply provides pilot-frequency excitation signals, the measurement unit realizes synchronous acquisition, and the signal processing module performs anti-interference and amplification processing. The method comprises the steps of line simulation wiring, synchronous time synchronization, pilot frequency signal acquisition, parameter calculation and error verification, and pilot frequency parameters are converted into power frequency parameters by using a frequency conversion formula. According to the invention, power frequency interference can be effectively suppressed in a charged environment, high-precision measurement of zero-sequence impedance and mutual inductance parameters of a mutual inductance line is realized by using pilot frequency excitation and Beidou synchronization technologies, the measurement error is remarkably reduced, the safety and reliability are remarkably improved, and powerful technical support is provided for safe and stable operation of a power system.

The invention relates to a harmonic stability analysis method and device, computer equipment and a storage medium. The method comprises the following steps: acquiring equipment data of a target inverter and system operation data of a power system; the target inverter comprises a network-following type inverter and a network-constructing type inverter, and the system operation data comprises power transmission line parameters and system topology data; constructing each equivalent model in the power system based on the equipment data of the target inverter and the parameters of the power transmission line; processing each equivalent model according to system topology data to obtain a node admittance matrix, and determining a target inherent mode corresponding to the power system based on the node admittance matrix and variable parameters of the power system; and evaluating the power system based on the attenuation coefficient of the target inherent mode to obtain an evaluation result corresponding to the harmonic stability of the power system. By adopting the method, a complex power system can be simplified, the harmonic stability of the system is quantified, the change trend of the harmonic of the system is directly judged, and the accuracy is improved.

The application discloses a kind of materials electromagnetic performance test methods of measuring reflection and transmission, belong to microwave measurement technology, and measurement system is formed by transceiver antenna, vector network analyzer, computer;The method comprises the following steps: installing the measurement system of measuring reflection and transmission based on space transmission line method;Four measurements are carried out in reflection area, respectively empty load test, reflection test, test piece test, test piece plus backplate test;According to the four groups of reflection coefficients measured, the transmission line parameters related to the transmission field of the material to be measured are calculated, and the transmission field size and phase of the transmission area are calculated according to the transmission line parameters.The application provides a kind of high-precision, non-destructive, easy-to-operate reflection measurement method, which can predict the transmission field distribution of the material to be measured under a specific incoming wave through reflection measurement.

The application discloses a time-domain fault location method and system for a high-voltage transmission line, and the method comprises the following steps: acquiring and establishing a telegraph equation of the transmission line according to the line structure and the transmission line parameters of the high-voltage transmission line; performing difference discretization on the telegraph equation of the transmission line in the time domain to establish a first-order differential equation; performing matrix conversion on the first-order differential equation to obtain a matrix form equation, and performing space integral conversion on the matrix form equation to obtain a space integral equation; and measuring the fault point position of the high-voltage transmission line according to the space integral equation and the synchronous measurement information of the two ends of the fault line through the voltage continuity principle along the transmission line. The embodiment realizes efficient determination of the fault point position, is not affected by calculation conditions such as difference format and step length, and has high location accuracy.

The application discloses a kind of flexible direct current transmission line fault transient electrical quantity determination methods, comprising: according to the circuit parameter of MMC converter station, construct MMC equivalent circuit when inter-pole short circuit;According to the transmission line parameter obtained, establish the equivalent model of two-port of direct current transmission line under complex frequency domain;According to the equivalent circuit of MMC when inter-pole short circuit and the equivalent model of two-port of direct current transmission line, obtain the expression of direct current fault transient under complex frequency domain;The expression of direct current fault transient under complex frequency domain is carried out Laplace transformation to obtain time domain response, the whole trend of transient process after fault can be given more accurately by the application.The calculation process is simple, avoids the complicated modeling simulation process in traditional simulation method.Meanwhile, it can well reflect the occurrence wave process when overhead line fails.The method can accurately express the overall development trend of the fault current flowing through the protection installation before the converter station is locked after the fault occurs, and has a positive significance for the fault current suppression and protection setting design of MMC-HVDC system.

A segmented modeling method based on a symmetrical sectioning traveling wave electrode electro-optical modulator comprises the steps that modeling simulation is conducted on the electrical property of an electro-optical modulation material of a silicon optical modulator, and electrical parameter data are extracted; carrying out optical simulation on a laser waveguide formed by the preprocessed electro-optical modulation material, extracting optical waveguide parameter data, carrying out modeling simulation on a no-load traveling wave electrode, extracting transmission line parameter data, carrying out small signal modeling analysis and calculation, and obtaining a small signal model; and step-by-step segmentation processing is carried out on the traveling wave electrode with the medium load in a symmetrical segmentation mode, data analysis and extraction are carried out on a simulation result, a parameter result of system design is obtained, and the problems of large calculation amount, low speed and low efficiency can be solved.

The application discloses an inertia estimation method suitable for large-scale wind farms, comprising the following steps: obtaining virtual synchronous generator (VSG) operation parameters corresponding to each wind turbine in the wind farm and alternating current (AC) power transmission network parameters, performing power flow calculation to obtain the voltage of each wind turbine VSG and the coupling node of the AC power transmission network; calculating the admittance matrix of the AC power transmission network according to the AC power transmission line parameters, and calculating the eigenvalue of the admittance matrix according to the admittance matrix; and determining the inertia of the entire wind farm according to the eigenvalue of the admittance matrix and the inertia constant of the VSG. The application considers the coupling effect of the AC network of the wind farm to calculate the inertia of the entire wind farm under the VSG control mode, thereby reducing the inertia calculation error of the wind farm, especially the large-scale wind farm.

The invention relates to the technical field of electronic design automation, and discloses a multi-conductor transmission line distribution parameter calculation method, a readable storage medium and electronic equipment. The multi-conductor transmission line distribution parameter calculation method comprises the steps of obtaining multi-conductor transmission line parameters of a printed circuit board to be simulated; for a conductor transmission line with a rectangular cross section, a first type Chebyshev polynomial is used as an expansion function to unfold charge density distribution on the surface of a conductor, the zero point of the first type Chebyshev polynomial is a Gaussian-Chebyshev integral point, discretization processing is carried out on an integral equation, and the integral equation is converted into a linear equation set; and solving the linear equation set to obtain a charge distribution coefficient, and determining charge distribution on the surface of the conductor according to the coefficient. According to the technical scheme, the Chebyshev polynomial is adopted as the primary function to expand and represent the to-be-solved charge density on the segments, a traditional primary function is replaced, the calculation precision is high, and the calculation amount is small.

This invention discloses a fast N-1 fault analysis method and system based on graph neural networks. The method includes: identifying transmission line parameters based on real-time measurement data to ensure the accuracy of physical parameters in the power system diagram; constructing the power system diagram; processing known and unknown features using a mask encoder; constructing a graph neural network architecture based on topology adaptive graph convolution; embedding the physical constraints of the power system into the loss function of the graph neural network; training a dedicated graph neural network model for each credible N-1 fault using power flow calculation data including normal operation and fault states; and applying the model for rapid fault analysis. The fast N-1 fault analysis method and system based on GNN proposed in this invention significantly improves analysis efficiency, reduces computation time, and maintains high prediction accuracy by training a dedicated model to predict branch power flow after a fault, effectively enhancing the operational safety and reliability of the power grid.

The application discloses a method and device for calculating nominal electric field of direct current transmission based on a firefly algorithm, and relates to the technical field of high-voltage engineering and computational electromagnetics. The method comprises the following steps: obtaining transmission line parameters, setting the number of simulation electric charges, the number and coordinates of matching points and verification points for each conductor, and calling a preset simulation electric charge method calculation framework to solve simulation electric charge quantity vectors and target functions; encoding all simulation electric charge coordinates into optimization variables, randomly generating an initial population and calculating brightness through the firefly algorithm, iteratively optimizing simulation electric charge positions, and finally obtaining a terminal generation optimal simulation electric charge position vector, which is substituted into the calculation framework to calculate a terminal generation optimal simulation electric charge quantity vector, and then the ground nominal electric field is solved. The optimal position of the simulation electric charge is searched through the firefly algorithm, the calculation precision of the ground electric field of the direct current transmission line is improved, and reliable technical support is provided for the ground nominal electric field evaluation under the static electric field condition of the direct current transmission line.

The invention provides a power transmission line loss identification method and device for small-region dynamic integration, relates to the field of power transmission, and solves the technical problem of low calculation precision of large-area power transmission line loss in the prior art. The method comprises the following steps: acquiring power transmission line parameters, power supply end parameters, power selling end parameters and environment-friendly energy parameters of a large area; pre-processing the power transmission line parameters, the power supply end parameters, the power selling end parameters and the environment-friendly energy parameters, aligning and establishing a hierarchical association mapping table; dividing the large area according to a hierarchical association mapping table to obtain a plurality of small areas; analyzing the line loss of the plurality of small regions to obtain a plurality of corresponding sub-line losses; and summing the plurality of sub-line losses to obtain the large-area power transmission line loss. The method is used in a large-area power transmission line loss identification process. According to the invention, the large area is planned into a plurality of small areas, and then the small areas are analyzed, thereby avoiding the large difference of line loss caused by the large difference of the specific power utilization conditions of each area.

The present application relates to the technical field of power grid operation and maintenance, and more particularly to a transmission line parameter measurement safety and reduction decision method, system and medium, the method comprising: obtaining the operating parameters and spatial parameters of the line to be measured and the adjacent lines, and determining the target adjacent line; based on the operating parameters and spatial parameters, determining the coupling parameters, and calculating the electrostatic induction voltage and electromagnetic induction voltage; according to the electrostatic induction voltage, electromagnetic induction voltage and spatial relationship, determining the total electrostatic induction voltage and total electromagnetic induction voltage; comparing the total electrostatic induction voltage and total electromagnetic induction voltage with the corresponding safety limits respectively; when the limit is exceeded, determining the accompanying stop line according to the induction influence contribution, and updating the total electrostatic induction voltage and total electromagnetic induction voltage; repeating the determination of the accompanying stop line and updating until none of them exceeds the limit, and generating the parameter measurement accompanying stop decision result. Through the present application, the problem that the existing line parameter measurement accompanying stop decision is difficult to accurately determine the necessary accompanying stop range is effectively solved.

The invention discloses a converter augmentation switching control method based on transmission line parameter online identification. Aiming at the problem that the stability margin of a grid-connected inverter is reduced when the power grid strength is reduced to be a weak power grid, on the basis of injection current disturbance and voltage response measurement, a recursive least square method under a d-q reference system is adopted to identify a transmission line impedance model on line, the system short-circuit ratio is estimated on line, and according to a short-circuit ratio evaluation result, the stability margin of the grid-connected inverter is reduced. And correspondingly switching the control modes of the grid-connected converter and the grid type control or the grid construction type so as to reduce the influence of the stability margin change caused by the weakening of the power grid strength. According to the method, parameter identification can be effectively carried out on a transmission line, online estimation of the short-circuit ratio is completed, a control mode is correspondingly adjusted according to different power grid strength, and the adaptation characteristic of the grid-connected converter unit under the power grid strength change is enhanced.

This invention discloses a method and apparatus for analyzing the sensitivity of broadband impedance of an AC system to transmission line parameters. The method includes: establishing impedance models for the transmission line, transformer, and load in the AC system; determining the sequence node admittance matrix at each harmonic frequency based on the impedance models and the topology of the AC system; determining the equivalent impedance of the AC system at each harmonic frequency by performing Cronbach's averaging on the sequence node admittance matrix; and calculating the derivative of the equivalent impedance of the AC system with respect to the transmission line parameters to obtain the sensitivity of the AC system to the transmission line parameters. This invention quantitatively characterizes the impact of changes in line parameters on broadband impedance response by calculating the equivalent impedance of the AC system at each harmonic frequency and differentiating it with respect to the transmission line parameters, thus providing a basis for the analysis and evaluation of broadband oscillation problems.

This application provides a method for determining the Rayleigh damping ratio coefficient of an icing unit in an icing transmission line. After determining the first transmission line parameters and first damping ratio before icing, and the second transmission line parameters and second damping ratio after icing, the method can determine the first mode frequency of the target transmission line under the first mode shape before icing based on the first transmission line parameters, and determine the second mode frequency of the target transmission line under the second mode shape after icing based on the second transmission line parameters. Thus, the Rayleigh damping algorithm can be used to calculate the first mass damping ratio coefficient and the first stiffness damping ratio coefficient of the target transmission line before icing, and the second mass damping ratio coefficient and the second stiffness damping ratio coefficient after icing. Finally, the third mass damping ratio coefficient and the third stiffness damping ratio coefficient of the icing unit are calculated, thereby enabling accurate calculation of the dynamic response of the line under icing and partial icing conditions.

The invention relates to a same-tower double-circuit power transmission line parameter estimation method and device based on parameter set selection, in particular to the technical field of power systems, and the method comprises the steps: obtaining line parameters corresponding to a same-tower double-circuit power transmission line; determining equivalent self-parameters and equivalent mutual parameters corresponding to the line parameters according to tower structure characteristics of the same-tower double-circuit transmission line, and obtaining parameter sets corresponding to the equivalent self-parameters and the equivalent mutual parameters; in response to an external fault of the same-tower double-circuit power transmission line, acquiring electrical quantity data corresponding to the same-tower double-circuit power transmission line; according to a target function and the electrical quantity data corresponding to the parameter set, estimating a line parameter estimation value corresponding to the line parameter, the line parameter estimation value being used for performing line maintenance of the same-tower double-circuit transmission line, and the target function being used for performing line maintenance of the same-tower double-circuit transmission line according to a zero-sequence parameter of a first circuit put into operation in the same-tower double-circuit transmission line; and solving a zero sequence parameter of a newly built second circuit line in the same-tower double-circuit power transmission line.