63 results about "Transmission line parameters" patented technology

The invention discloses a rapid N-1 fault analysis method and system based on a graph neural network. The method comprises the following steps: performing power transmission line parameter identification based on real-time measurement data to ensure the accuracy of physical parameters of a power system diagram; constructing a power system diagram; known and unknown features are processed in combination with a mask encoder; constructing a graph neural network architecture based on topological adaptive graph convolution; embedding the physical constraint of the power system into a loss function of the graph neural network; for each credible N-1 fault, training a special graph neural network model by using power flow calculation data including a normal operation state and an accident state; and carrying out fault rapid analysis by using the model. According to the GNN-based rapid N-1 fault analysis method and system provided by the invention, the branch power flow after the fault is predicted by training the special model, so that the analysis efficiency is remarkably improved, the calculation time is shortened, relatively high prediction precision is kept, and the operation safety and reliability of a power grid are effectively enhanced.

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 discloses a circuit board printing control method and system based on signal transmission loss. And obtaining a target differential transmission line parameter and a circuit board lamination parameter. And establishing an electromagnetic simulation model, and simulating insertion loss, return loss and impedance discontinuous point distribution. The line width, the line spacing and the interlayer hollowed-out area of the differential transmission line are dynamically adjusted through the reinforcement learning model, the proportion of the line width to the shielding layer spacing is limited by a preset critical value, and the line spacing is configured based on the multiple relation of the shielding layer spacing. And a sectional optimization strategy is adopted for the corners of the transmission line. The ratio of the aperture to the diameter of the anti-pad is optimized, and impedance mutation is reduced. According to the method, the key parameters of the target differential transmission line and the circuit board lamination parameters are acquired, and the electromagnetic simulation model is combined with the multi-physical field coupling algorithm, so that the insertion loss, the return loss and the impedance discontinuous point distribution can be accurately simulated. The method improves the adjustment efficiency, guarantees the accuracy of an adjustment result, and effectively reduces the signal transmission loss.

The invention relates to the technical field of signal crosstalk prevention, and provides an FFC wire harness signal crosstalk prevention method and device, electronic equipment and a storage medium. The method comprises the steps of performing frequency spectrum and time domain feature extraction processing on an original FFC signal to obtain a basic signal parameter set, constructing an FFC wire harness electromagnetic model according to FFC wire harness geometric data, and performing multi-conductor transmission line parameter extraction processing according to the basic signal parameter set and the FFC wire harness electromagnetic model to obtain a distribution parameter matrix. And performing Pareto multi-objective optimization processing on the signal arrangement sequence and daemon insertion of the distribution parameter matrix to obtain an optimal signal sequence and a daemon scheme, and performing microstructure configuration processing of the overall shielding layer and the grounding network according to the optimal signal sequence and the daemon scheme to obtain a shielding arrangement scheme. According to the invention, through fine modeling and multi-target collaborative optimization, the FFC wire harness realizes low crosstalk, high bandwidth and low electromagnetic radiation in a high-frequency and high-speed transmission environment.

A technique is disclosed to use time series phasor data to perform real-time dynamic line rating of electric power transmission lines. A variety of techniques are used to generate well-poised solutions to the determination of transmission line parameters from phasor data. Line health information can also be determined from changes to transmission line parameters, such as galloping, icing, vegetation encroachment, imperfect splicing, and conductor corrosion.

The invention aims to provide a new energy high-frequency wire harness design method based on electromagnetic compatibility optimization, and relates to the technical field of new energy, and the method comprises the steps: 1, building a new energy high-frequency wire harness type electromagnetic source model, and obtaining the electromagnetic source intensity; calculating a spatial electromagnetic field intensity based on the electromagnetic source intensity; step 2, calculating equivalent transmission line parameters based on the space electromagnetic field intensity; based on the equivalent transmission line parameters, frequency-dependent characteristic impedance is calculated; step 3, calculating crosstalk voltage according to the frequency-variable characteristic impedance; calculating a radiation field of the new energy high-frequency wire harness; calculating the shielding effectiveness of the new energy high-frequency wire harness according to the radiation field; 4, according to the step 1, the step 2 and the step 3, constraint conditions are set, an objective function under the constraint conditions is established, and the objective function is solved through iteration to find the corresponding optimal design parameter vector of the new energy high-frequency wire harness. According to the invention, the transmission stability and the anti-interference capability of the new energy high-frequency wire harness are significantly improved.

A segmented modeling method based on symmetrical segmentation of a travelling-wave electro-optic modulator, comprising steps: performing modeling simulation on electrical properties of an electro-optic modulation material of a silicon photonic modulator, and extracting electrical parameter data; performing optical simulation on a laser waveguide formed by the preprocessed electro-optic modulation material, and extracting optical waveguide parameter data; performing modeling simulation on an unloaded traveling-wave electrode, and extracting transmission line parameter data; performing small signal modeling analysis and calculation, and performing step-by-step segmentation processing on a medium-loaded traveling-wave electrode in a symmetrical segmentation manner, and performing data analysis and extraction on a simulation result to obtain a parameter result of system design; and the like. The problems of large amount of calculation, low speed and low efficiency can be solved.

The invention discloses a method for measuring and calculating parameters of a same-tower double-circuit alternating-current transmission line under high induced voltage. The method comprises the following steps: dividing the same-tower double-circuit transmission line into three groups of wiring modes; measuring the short-circuit impedance in each wiring mode and the line impedance in a mode that the tail end of the line is grounded through impedance; calculating the characteristic impedance and the propagation coefficient in the corresponding wiring mode by using the impedance measurement result of the line through impedance grounding and the line short-circuit impedance measurement result in each wiring mode, and further calculating the distribution impedance and the distribution admittance in the corresponding mode; and finally, calculating the resistance, inductance and ground capacitance of each phase lead of the same-tower double-circuit line, the inter-phase coupling capacitance and inter-phase coupling inductance of the single-circuit line, and the coupling capacitance and coupling inductance between each phase lead of the double-circuit line through the distributed impedance and distributed admittance in each wiring mode and simultaneous equations. Through the method, the induced voltage on the measured circuit can be effectively reduced, and meanwhile accurate measurement can be achieved.

The invention discloses an on-chip calibration part parasitic parameter extraction method based on a particle swarm algorithm. The method comprises the following steps: calculating a propagation constant of a transmission line to be measured through a TRL, calculating a direct-current resistance and a reflection coefficient of a calibration part to calculate line capacitance of the transmission line to be measured, establishing a calibration part parasitic parameter equivalent circuit model, and calculating a real scattering parameter of the calibration part according to a parasitic parameter; 12 error terms are calculated according to the real scattering parameters of the calibration piece and the scattering parameter measurement values; and setting a target function as a constraint condition to enable the calibration value of the transmission line to be measured to approach the real scattering parameter of the transmission line to be measured, optimizing the parasitic parameter by using a particle swarm algorithm, and outputting a group of optimal parasitic parameters. According to the method, the real scattering parameters of the transmission line are calculated by modeling the transmission line model, and the parasitic parameters are optimized by using the particle swarm optimization to aim at enabling the calibrated transmission line parameters to approach the real values, so that the accuracy of the parasitic parameters of the calibration piece is effectively ensured.

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 invention discloses a circuit board production process management and control method and system based on a multilayer circuit. The method comprises the following steps: establishing an interlayer transmission line parameter model of a multilayer circuit board, and calculating electromagnetic field distribution based on a deformation telegraph equation and a parallel plate resonance effect; performing transmission characteristic simulation verification; optimizing production environment parameters, and selecting an area of which the electric field intensity is lower than 45% maximum value as a wiring optimal area; implementing a layered wiring strategy, and optimizing an interlayer wiring path according to the transmission matrix; production data are dynamically monitored, temperature, humidity and electromagnetic radiation data are collected in real time, and machining parameters are adjusted in combination with a transmission matrix correction value. According to the method, the transmission characteristics are accurately predicted, the production environment parameters are optimized, the influence of the external environment on the performance of the circuit board is effectively reduced, and the stability and reliability of the circuit board are improved. Through establishment of a parameter model and simulation verification, comprehensive management and control of the production process of the multilayer circuit board are realized.

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 invention provides an ultra-high voltage transmission line parameter test control system and method, and belongs to the technical field of ultra-high voltage transmission line parameter test control. The technical problem to be solved is to provide a hardware structure of an ultra-high voltage transmission line parameter test control system and an improvement of a control method. According to the technical scheme adopted for solving the technical problem, the system comprises a wireless console, a parameter tester, a first main station switching device, a second main station switching device, a first auxiliary station switching device and a second auxiliary station switching device; the parameter tester is connected with the first master station switching device and the second master station switching device through test wires. The first main station switching device as a head end is connected with the first auxiliary station switching device as a tail end through a first test power transmission line; the second main station switching device serving as the head end is connected with the second auxiliary station switching device serving as the tail end through a second test power transmission line; the method is applied to parameter testing of the ultra-high voltage transmission line.

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.

The present invention provides a linear self-disturbance rejection supplementary damping method and device for suppressing subsynchronous oscillations, including initializing the transmission line parameters and unit parameters; introducing LADRC on the rotor side and performing feedback control according to the state error; superimposing the output of the supplementary damping controller on the rotor side current loop to improve the positive damping of the control system; superimposing the disturbance on the rotor side current loop to suppress the subsynchronous oscillation of the doubly fed wind farm. In the rotor side inner loop control, the LESO with self-disturbance rejection control is used to estimate and feedback compensate the subsynchronous disturbance of the system in real time. The output of the supplementary damping controller is superimposed on the rotor side current loop to improve the positive damping of the control system to suppress low-frequency oscillations. It does not require complex parameter setting, has good anti-interference ability to changes in system operating conditions, and shows stronger robustness under high series compensation conditions with higher oscillation frequencies. It aims to solve the problem that doubly fed wind farms with series compensated transmission lines may aggravate subsynchronous oscillations of the power system.

This invention discloses a distance protection method, device, and terminal equipment for a virtual synchronous generator grid-connected system based on the least squares method. The method includes: constructing a grid-connected system model based on acquired virtual synchronous generator parameters, power equipment parameters, and transmission line parameters; when the synchronous generator parameters in the power equipment parameters are empty, constructing a fitting objective function for the grid-connected system model and a set of equations containing the impedance from the fault point to the protection; solving the set of equations containing the impedance from the fault point to the protection with the objective function as the goal, and calculating the first impedance from the fault point to the protection; determining the location of the fault point based on the first impedance from the fault point to the protection and the virtual synchronous generator parameters; and performing distance protection on the virtual synchronous generator grid-connected system based on the location of the fault point. By implementing this invention, the location of the fault point in the virtual synchronous generator connected to the power grid can be accurately obtained.

The invention relates to the technical field of power transmission line monitoring, in particular to a power transmission line parameter monitoring and early warning method and system based on industrial big data, and the method comprises the steps: analyzing the fixed state of a power transmission line between adjacent iron towers through environment detection data, iron tower position data and line connection data; analyzing the line response efficiency of the power transmission line between the adjacent iron towers through the power transmission line parameter data; based on the analysis result of the fixed state of the power transmission line between the adjacent iron towers and the analysis result of the line response efficiency, constructing a power transmission line working stability evaluation model, and evaluating the working stability of the power transmission line between the adjacent iron towers; and performing maintenance early warning on the power transmission line between the adjacent iron towers according to the working stability evaluation result of the power transmission line between the adjacent iron towers. The method achieves the differentiated evaluation of the risks of line segments in different directions, effectively compensates for the hysteresis of the conventional periodic inspection, facilitates the reduction of the fault occurrence probability, and improves the operation reliability of a power grid.

The present invention belongs to the technical field of transmission lines, and in particular relates to a calculation method for preventing transmission line galloping. The present invention comprises: step 1. obtaining the transmission line morphology under current conditions; step 2. fitting a curve model equation according to discrete points based on the transmission line morphology; step 3. calculating the stress value of the transmission line under the current state based on the curve model equation; step 4. calculating the transmission line sag equation using the curve model equation; step 5. estimating the transmission line model under different meteorological conditions; step 6. establishing a transmission line galloping ellipsoid model to determine whether the phase-to-phase distance exceeds the limit. Under severe meteorological conditions, when the transmission line sag morphology cannot be obtained, the present invention can realize real-time monitoring of transmission line galloping through previously collected transmission line parameters, combined with micro-meteorological information and line parameters, so as to achieve the purpose of early warning and effectively maintain the stable operation of the power system.

The application discloses a kind of based on multilayer circuit's circuit board production process management and control method and system.Method includes establishing the interlayer transmission line parameter model of multilayer circuit board, electromagnetic field distribution is calculated based on deformation telegraph equation and parallel plate resonance effect;Transmission characteristic simulation verification is carried out;Optimize production environment parameters, select the area where electric field intensity is lower than 45% maximum value as wiring preferred area;Implementation layered wiring strategy, according to transmission matrix optimization interlayer wiring path;Dynamic monitoring production data, real-time acquisition temperature, humidity, electromagnetic radiation data, combined with transmission matrix correction value adjustment processing parameter.The method accurately predicts transmission characteristics, optimizes production environment parameters, effectively reduces the influence of external environment on the performance of circuit board, improves the stability and reliability of circuit board.Through the establishment of parameter model and simulation verification, the overall management and control of multilayer circuit board production process is realized.

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 utility model relates to the technical field of low-voltage cabinet test grounding protection, and discloses a low-voltage cabinet power transmission line parameter test grounding protection device comprising a sealing cover, the bottom of the sealing cover is provided with an adsorption ring used for adsorption fixation with a cabinet body, and the top of the sealing cover is rotatably provided with a rotating shaft through a bearing. And the bottom end of the rotating shaft penetrates through the sealing cover and extends into the sealing cover. According to the low-voltage cabinet power transmission line parameter test grounding protection device, through cooperation of the rotating shaft, the limiting sleeve and the holding handle, pressing force on the holding handle is converted into rotating force for driving the rotating shaft to rotate, and then the rotating shaft drives the grinding device to rotate so as to grind the contact surface; paint, dust and rust on the surface of the contact surface connected with the ground are ground and removed through grinding, the subsequent grounding quality is improved, the protection effect is improved, and the device further has the advantages of being easy to operate and convenient to use.

The application aims to provide a new energy high-frequency wire harness design method based on electromagnetic compatibility optimization, and relates to the technical field of new energy, which comprises the following steps: step 1: an electromagnetic source model of the new energy high-frequency wire harness is established to obtain electromagnetic source intensity; based on the electromagnetic source intensity, the spatial electromagnetic field intensity is calculated; step 2: based on the spatial electromagnetic field intensity, the equivalent transmission line parameters are calculated; based on the equivalent transmission line parameters, the frequency-varying characteristic impedance is calculated; step 3: according to the frequency-varying characteristic impedance, the crosstalk voltage is calculated; the radiation field of the new energy high-frequency wire harness is calculated; according to the radiation field, the shielding effectiveness of the new energy high-frequency wire harness is calculated; step 4: according to step 1, step 2 and step 3, the constraint condition is set, and the objective function under the constraint condition is established; the objective function is solved by iteration to find the optimal design parameter vector of the corresponding new energy high-frequency wire harness. The application significantly improves the transmission stability and anti-interference ability of the new energy high-frequency wire harness.

A transmission line parameter estimation apparatus includes: a storage unit configured to stores in advance a non-linear phase rotation amount distribution obtained by using time waveform data acquired from a receiver, of a first transmission line, and a non-linear phase rotation amount of a second transmission line different from the first transmission line; and a controller configured to refer to data in the storage unit, and obtains a non-linear constant of each span of the second transmission line based on a distribution of the non-linear phase rotation amount.

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 rapid development of power electronic technology represented by DC power transmission has injected a large amount of harmonics into the power grid, resulting in the characteristics of wide frequency and multi-source of the grid harmonics. In order to effectively monitor the complex grid harmonics and take into account the economy of the measurement system, the current mainstream measures are to install wide frequency synchronous phasor measurement units (bPMU) at some key nodes and to use harmonic state estimation technology to calculate the harmonic state of the remaining nodes. However, under this technical framework, the accuracy of harmonic state estimation depends on the accuracy of the grid impedance parameters. Since the line parameters are affected by the harmonic frequency, system operation mode and many environmental factors, it is difficult to realize real-time and accurate acquisition of the grid parameters in practical application, which leads to the decrease of the accuracy of harmonic state estimation. In view of this, the present invention discloses a grid wide frequency harmonic state estimation adaptive correction method for grid impedance parameter error, which can correct the grid impedance parameter error of a specific frequency band based on the wide frequency measurement data of the specific frequency band and correct the harmonic state estimation result. The core idea is to use the harmonic state estimation result to correct the grid impedance / admittance parameters and to re-estimate the grid harmonic state based on the corrected parameters. This cycle is repeated until the calculation result converges. The example results show that the strategy proposed in the present invention can effectively improve the accuracy of the harmonic state estimation result under the condition that there is an error in the grid impedance parameters.

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.

The present invention provides a method, medium and system for predicting the voltage stability of a distributed energy storage grid, belonging to the field of distributed energy storage technology, comprising: obtaining the parameters of each node based on the urban power grid topology of the distributed energy storage. A group of equations affecting the voltage of the energy storage grid is established based on these parameters, and the stability range of the parameters of each node is calculated. Based on the topology map and the stability range of the node parameters, the voltage stability margin of each node is calculated to form a topological map of the power grid voltage stability margin. The voltage stability margin matrix at multiple consecutive moments is input into a pre-trained prediction model, which can predict the voltage stability margin of each node in the future. The system comprehensively considers the impact of distributed energy storage on the voltage stability of the power grid, and solves the technical problem that the existing distributed energy storage grid voltage stability prediction method is difficult to solve, that is, the voltage stability analysis generalization ability is poor due to the randomness of load and power generation and the uncertainty of transmission line parameters.

A technique is disclosed to use time series phasor data to perform real-time dynamic line rating of electric power transmission lines. A variety of techniques are used to generate well-poised solutions to the determination of transmission line parameters from phasor data. Line health information can also be determined from changes to transmission line parameters, such as galloping, icing, vegetation encroachment, imperfect splicing, and conductor corrosion.

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.