32 results about "Power system oscillations" patented technology

The invention discloses a harbor shore power system oscillation damping suppression method based on heuristic probability optimization. According to the method, sliding window preprocessing is carried out on an alternating current bus side current time domain oscillation signal, modal decomposition is carried out based on a Prony algorithm, and modal energy is calculated to judge an oscillation mode; the discriminated oscillation modes are aggregated and mapped into equivalent circuit elements, a corresponding three-order circuit state matrix is constructed, and the damping ratio of each mode is determined according to the characteristic value of the matrix; taking a damping ratio as an evaluation index, introducing an influence factor to construct a multi-objective optimization function, parameterizing the parallel adjustable impedance, and limiting an adjustable range; and searching the control parameters by adopting a heuristic probability optimization strategy to obtain final damping control parameters, and downloading the final damping control parameters to the parallel adjustable impedance device to realize online dynamic adjustment. According to the method, multi-modal identification, physical magnitude mapping and online adaptive optimization can be realized, and the suppression capability and the operation stability of the shore power system on sub / super synchronous oscillation are improved.

The invention discloses a power system oscillation parameter identification method based on improved TVF-EMD, and the method comprises the steps: carrying out the preprocessing of an original PMU data stream, calculating a local cut-off frequency LCF through B-spline approximation, solving a signal local mean value through B-spline approximation, completing the time-varying filtering empirical mode decomposition, namely TVF-EMD decomposition, screening an effective IMF based on a correlation coefficient after the verification of a stop criterion, and carrying out the recognition of the oscillation parameter of a power system. Extracting an instantaneous frequency and a damping ratio through the TKEO; the method combines TVF-EMD with TKEO, can accurately estimate the modal parameters of the power system under the normal operation condition, including frequency and damping ratio, has robustness for the instantaneous mode characteristics in the power system under the condition of low calculation complexity, reduces the problems of modal aliasing and discontinuity easily occurring in the traditional EMD method, and improves the reliability of the power system. The method provides better performance in the aspects of predefined parameters and time-varying cut-off frequency, and is suitable for analysis of non-stationary signals.

The invention discloses a power system oscillation traceability analysis method and system based on multi-method probability fusion, which can effectively solve the problem of oscillation source positioning error caused by sparse measurement data and compressed sensing. Firstly, the oscillation source probability of each node is calculated through an oscillation energy method, a frequency spectrum characteristic method, a correlation analysis method, a voltage fluctuation method and a phase angle gradient method; secondly, calculating the adaptive weight of each method based on an information entropy theory, and completing multi-method probability fusion; the fusion probability is optimized in combination with a power grid topological structure, and an oscillation source candidate sequence is determined; and finally, a comprehensive probability distribution diagram and a detailed analysis report are output through a visual module, and reliable technical support is provided for safe and stable operation of a power system.

The invention discloses an online evaluation method and system for an oscillation monitoring algorithm, and the method comprises the steps: obtaining diversified oscillation test cases, and marking the oscillation characteristics of each case; the method comprises the following steps: configuring a test plant station in an actually running power system, adopting a high-precision sending mechanism by the test plant station, generating an analog data message consistent with a time mark and a format of an actual PMU message according to an oscillation test case, and sending the analog data message to a message bus; and performing oscillation detection on the analog data message received by the message bus by applying an oscillation monitoring algorithm, and comparing an oscillation detection result with the oscillation characteristics of the corresponding oscillation test case to obtain an evaluation result of the oscillation monitoring algorithm. The method can truly reflect the performance of the oscillation monitoring algorithm in an actual environment without influencing the actual operation of a power grid, improves the accuracy and reliability of the algorithm, has the advantages of high authenticity, high reliability and comprehensive coverage, and is suitable for online evaluation and optimization of the oscillation monitoring algorithm of the power system.

The application relates to the technical field of power system oscillation analysis, and discloses a method for identifying an ultra-high voltage direct current sending-out system oscillation source based on wavelet analysis. The method comprises the following steps: collecting electrical quantities of measuring points, pre-processing the electrical quantities to construct an input tensor, inputting the input tensor into four wavelet branches to perform five-layer convolution pooling to obtain feature maps, adaptively weighting and fusing the feature maps through a scale channel joint attention network, inputting the feature maps into a bidirectional long short-term memory network to calculate an oscillation source probability, an energy flow direction and a frequency energy in combination with historical states, and determining an oscillation source position according to a comprehensive criterion. The application solves the problems that wavelet basis selection depends on experience, multiple oscillation sources are difficult to separate, and dynamic tracking capability is lacking, and improves the accuracy and real-time performance of ultra-high voltage system oscillation source identification.

The invention relates to the technical field of power system oscillation analysis and control, and provides a multi-scale modeling-based broadband oscillation feature extraction and suppression method for a new energy high-proportion access system, and the method comprises the steps: building a multi-scale model which is used for describing a power system and comprises an electromagnetic transient model, an electromechanical transient model and a dynamic feature model; based on the multi-scale model, constructing a digital twinborn model which operates synchronously with the physical power system, and updating the state of the digital twinborn model in real time by adopting a data assimilation algorithm; utilizing a digital twinborn model to extract broadband oscillation characteristics of the power system; and generating a suppression strategy according to the broadband oscillation characteristics, and regulating and controlling the physical power system through the suppression strategy verified in the digital twinborn model. Furthermore, accurate extraction and effective suppression of broadband oscillation in the new energy high-proportion access system are realized.

The invention discloses a power system oscillation mechanism identification method and a model construction method, and relates to the field of power system low-frequency oscillation, and the method comprises the steps: collecting the active power data of a generator and the active power data of a tie line; performing linear normalization and principal component analysis dimension reduction processing on the data, and constructing a multi-dimensional time sequence to-be-tested sample; a sample is input into a pre-trained deep belief network (DBN) model, the model is formed by stacking a plurality of restricted Boltzmann machines (RBM), data deep features are extracted through unsupervised layer-by-layer greedy pre-training, and parameter optimization is performed in combination with supervised fine tuning. According to the method, negative damping oscillation and forced power oscillation can be automatically identified, the uncertainty of manual feature selection is avoided, the influence of noise and amplitude difference on the identification precision is effectively suppressed, and the adaptability of the model to an actual power grid complex disturbance condition is improved.

The invention discloses an automatic intelligent voltage regulation method for improving the electrical performance of an LNG ship, and the method comprises the steps: carrying out the preprocessing of real-time data after a power system enters a working state, transmitting the preprocessed data to a control system PID module, converting the data into a voltage regulation signal after the data is processed by the control system PID module, and transmitting the voltage regulation signal to an AVR system module, an algorithm model is preset in a PID module of a control system, the algorithm model is obtained by collecting historical data from an LNG ship power system, preprocessing the collected historical data, building the algorithm model through a long-short term memory neural network and a convolutional neural network and training the algorithm model, and the algorithm model is obtained through the algorithm model. The algorithm model feeds back and adjusts the voltage through intelligent prediction and multiple iteration processing, so that the output voltage reaches or approaches the standard voltage to realize stable balance. According to the method, the deep learning optimization algorithm is adopted, automatic adjustment of the LNG ship power system is achieved, oscillation and faults of the power system are reduced, and the overall performance of the ship is improved.

This application discloses a method and apparatus for tracing the source of power system oscillations, including converters and synchronous machines. Belonging to the field of power system transmission and distribution technology, the method involves: reducing the order of the power network and constructing its linearized admittance matrix; establishing port admittance matrices for all power supply equipment, including converters and synchronous machines, under small disturbances; establishing the port external admittance matrix of the synchronous machines, taking into account the impedance embedding of the converters, based on the port admittance models of the power supply equipment and the power network; sequentially calculating the port impedance of each synchronous machine and establishing its damping torque model; and identifying the synchronous machine providing negative damping torque based on the phase characteristics of the damping torque model, which is the low-frequency oscillation source of the system. This application does not require internal converter information, can achieve information isolation between different power sources, is applicable to converters with different control strategies, has clear physical meaning, can provide theoretical guidance for oscillation suppression in large-scale multi-machine power systems, and can be embedded in power system analysis software, making it of significant engineering importance.

The invention provides a novel power system oscillation early warning method and device, electronic equipment and a storage medium, and the method comprises the steps: setting an initial early warning threshold value, and periodically storing a plurality of oscillation-related characteristic values in a power system; selecting a target value from the characteristic values at an updating time point as a candidate early warning threshold value, wherein a preset time point is related to a storage period of the oscillation related characteristic values; comparing a candidate early warning threshold value with a current early warning threshold value to determine whether to update the early warning threshold value according to the candidate early warning threshold value; and carrying out oscillation early warning according to the oscillation related characteristic value and the early warning threshold value. By periodically storing various oscillation related characteristic values and dynamically adjusting the early warning threshold value, the early warning threshold value is adjusted in real time according to different working conditions of the power system and changes of the characteristic values, the actual operation state of the power system can be accurately determined, potential oscillation risks can be captured in time, and the accuracy of oscillation early warning is improved.

The invention provides a novel power system key electrical quantity oscillation monitoring method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining a monitoring electrical quantity collected by an electrical measurement point; according to the monitored electrical quantity and the periodic time parameter, calculating an oscillation characteristic value, the oscillation characteristic values comprise a single-cycle rolling characteristic value based on the reciprocating motion mileage, a long-cycle nested characteristic value based on the reciprocating motion mileage, a single-cycle rolling characteristic value based on the oscillation waveform area and a long-cycle nested characteristic value based on the oscillation waveform area; setting an oscillation alarm threshold value according to the oscillation characteristic value; and determining whether abnormal oscillation occurs or not according to the oscillation characteristic value and the oscillation alarm threshold value, and performing oscillation early warning. Through multi-dimensional and multi-time-scale feature extraction, the oscillation feature value is extracted from the monitored electrical quantity, and adaptive threshold setting is carried out, so that the accuracy, sensitivity and adaptability of oscillation monitoring of the power system are remarkably improved.

The invention discloses an L1 regularization and neural network-based power system sub / super synchronous oscillation parameter identification method and device applied to a synchronous phasor measurement device, and a storage medium, and belongs to the technical field of power system oscillation analysis. Recombining the non-missing parts into a continuous synchronous phasor sequence in sequence; 2, setting a neural network and a Fourier transform matrix as input, and setting a continuous synchronous phasor sequence as target output; 3, initializing weight parameters of the neural network; 4, adding L1 regularization as a penalty term of a target output error; 5, optimizing the network weight by using an RMSProp optimizer to obtain a solution of an equation set; and 6, calculating sub / super synchronous oscillation parameters according to a synchronous phasor algorithm in combination with the solution of the equation set. The method can be applied to a synchronous phasor measurement device, synchronous phasor data collected by the device serve as input of the method, and oscillation parameters of signals can be measured online.

The invention provides a power system oscillation source positioning method and device, electronic equipment and a storage medium, and relates to the technical field of power system oscillation analysis, and the method comprises the steps: obtaining a three-phase voltage instantaneous sampling value and a three-phase current instantaneous sampling value of each port in a plurality of ports of a power system; based on the three-phase voltage instantaneous sampling value and the three-phase current instantaneous sampling value, calculating to obtain instantaneous total power and a steady-state direct-current power component of each port; calculating a difference value between the instantaneous total power and the steady-state direct-current power component to obtain a net power component of each port; and analyzing the net supply energy change trend of the plurality of ports based on the net power component of each port, and determining an oscillation source in the plurality of ports based on the net supply energy change trend. According to the method provided by the invention, the oscillation source criterion based on the net supply energy is more reliable, and misjudgment caused by improper removal of the direct current component is reduced.

This invention discloses a method, system, and device for identifying subsynchronous oscillation modes under environmental excitation, belonging to the field of power system oscillation detection. Kalman filtering (KF) is used to estimate the coefficients of an autoregressive (AR) model to fit measured environmental data. The damping factor and frequency of the subsynchronous oscillation (SSO) mode can be directly obtained by solving for the roots of the characteristic polynomial corresponding to the AR model. Furthermore, multi-model segmentation filtering (MMPF) is applied to KF to select the correct AR model order. This invention combines the KF algorithm with MMPF, enabling the algorithm to directly identify weak SSO mode parameters from environmental data. The method has simple operation steps and short response time, thus possessing good application prospects.

The present application belongs to the technical field of power system oscillation suppression, and specifically discloses an oscillation suppression method and system based on high-inertia energy storage type phase modifier impedance remodeling, which comprises the following steps: identifying a target suppression frequency band; obtaining the active power signal of a grid-connected new energy unit or new energy station, and performing band-pass filtering to obtain the subsynchronous and / or supersynchronous oscillation component of the target suppression frequency band; performing asymmetric complex number lead correction on the oscillation component; after amplitude shaping and safety limiting of the phase-compensated signal, the signal is injected into the rotor-side converter power outer ring of the high-inertia energy storage type phase modifier as an additional control signal to form an additional power deviation; the deviation is output as a rotor-side current reference value after PI regulation, and then a damping power opposite to the oscillation component is formed on the stator side to remodel the equivalent output impedance of the point of common coupling. The present application can suppress the subsynchronous and / or supersynchronous oscillation of the new energy station.

The invention discloses a power system low-frequency oscillation monitoring and analysis method, system, equipment and medium, and relates to the technical field of power system analysis, and the method comprises the steps: reading PMU data, and extracting oscillation features according to fluctuation changes; if an oscillation sign occurs, rapidly determining the oscillation frequency by using fast Fourier transform (FFT), and if the adjacent stations of the regional power grid detect oscillation at the same frequency, determining that the power grid oscillates; based on the oscillation characteristic data, weak damping oscillation monitoring analysis is carried out, and an online grouping result of a synchronous power grid unit and a node injection active power oscillation mode is output; and performing forced oscillation monitoring analysis, and outputting an oscillation source positioning result of the synchronous power grid based on transient energy integration. The method can quickly confirm the oscillation mode and the oscillation source when the power system oscillates, assists a dispatcher in quickly and accurately understanding the situation of the oscillation source of the power grid, takes effective measures to eliminate the influence of low-frequency oscillation on the operation of the power grid, and improves the safety and stability of the power system.

The invention discloses a broadband oscillation traceability method for a power system driven by measurement data, and relates to the technical field of power system oscillation analysis. According to the invention, based on port voltage and current instantaneous measurement data of a power generation unit or a grid-connected node, a target broadband oscillation frequency is identified through frequency domain analysis, and corresponding voltage and current oscillation mode components are extracted; then constructing modal power under the modal to represent oscillation energy exchange characteristics; and finally, according to the sign and the change characteristic of the modal power, determining that the unit or the node which continuously injects oscillation energy into the system is a broadband oscillation source. The method is low in model dependency, visual in positioning and suitable for a new energy high-proportion power system, and provides a basis for oscillation suppression.

The invention relates to a power supply oscillation suppression system and a power supply oscillation suppression method, the power supply oscillation suppression system comprises an oscillation detection module and an oscillation suppression module, and the oscillation detection module is connected with a wave trap; the wave trap is used for acquiring oscillation information from the oscillation detection module and updating parameters of the wave trap according to the oscillation information to suppress oscillation, the synchronous generator is used for remodeling power supply impedance from a current source type to a voltage source type, and the additional damping controller is used for injecting an inversion signal into a current loop to offset the oscillation. Oscillation is rapidly detected through an oscillation detection module, oscillation is suppressed through a wave trap in an oscillation suppression module, power supply impedance is remodeled from a current source type to a voltage source type through a synchronous generator, damping resistance of a power system is improved from the source, and an anti-phase signal is injected into a current loop through an additional damping controller to offset an oscillation component. The oscillation energy attenuation is accelerated, the oscillation suppression capability of the power system is improved, and the stability of the power system is improved.

The invention provides an oscillation identification method and device, equipment, a storage medium and a product. The method comprises the following steps: dividing waveform data of a power system into a plurality of sub-data according to a preset time window and a preset sliding step length; based on a margin index algorithm, separately determining margin indexes corresponding to the sub-data; the margin index represents the fluctuation degree of the current in the time window corresponding to the sub-data; determining an oscillation starting moment based on a difference value between each margin index; fourier transform is carried out on waveform data corresponding to the oscillation starting moment to obtain corresponding frequency domain data, and the waveform data and the frequency domain data are combined into a time-frequency domain data set; and inputting the time-frequency domain data set into a preset deep learning model, and determining the oscillation type of the power system. The time-frequency domain data is input into the preset deep learning model for classification, so that the complexity and subjectivity of manual feature extraction are avoided, the accuracy and efficiency of power system oscillation type recognition are improved, and oscillation in the power system can be quickly and accurately recognized.

The invention relates to the technical field of power system stability analysis, in particular to a quantitative analysis method and device for logarithmic derivatives of a dominant oscillation mode of a power system, and the method comprises the steps: determining the frequency step size of the power system, and obtaining the logarithmic derivative of an admittance matrix determinant according to the frequency step size; acquiring a real part extreme point and an adjacent frequency point of the logarithmic derivative, and pre-identifying a dominant oscillation mode of the power system according to the real part extreme point and the adjacent frequency point; and calculating oscillation damping and frequency of the power system according to the dominant oscillation mode. Therefore, the problem that the accuracy of oscillation source identification and system stability evaluation is affected due to inaccurate estimation of key parameters such as the damping ratio and the oscillation frequency in the dominant oscillation mode due to the fact that the influence of the frequency step length on the parameter identification precision is not fully considered in an electric power system oscillation analysis method is solved.

The invention discloses a power system oscillation alarm false alarm prevention method and system based on multi-source data checking. The method comprises the steps that a master station monitors oscillation alarm in real time; when the main station monitors an oscillation alarm, triggering oscillation checking based on the broadband data real-time checking path so as to judge whether the oscillation alarm is caused by spectrum aliasing or not; when the oscillation alarm is judged to be caused by spectrum aliasing based on the broadband data real-time checking path, the master station issues an oscillation false alarm, otherwise, the master station triggers oscillation checking based on the high-sampling wave recording calling checking path; carrying out oscillation checking based on a high-sampling wave recording call checking path so as to check whether the oscillation alarm is caused by spectrum aliasing; and when the oscillation check based on the high-sampling wave recording call check path judges that the oscillation alarm is caused by spectrum aliasing, the master station issues an oscillation false alarm. According to the invention, the problem of oscillation false alarm caused by spectrum aliasing is solved.

The application discloses a port shore power system oscillation damping suppression method based on heuristic probability optimization. The method carries out sliding window pretreatment on the time domain oscillation signal of the current on the AC bus side and implements modal decomposition based on the Prony algorithm, calculates modal energy to identify the oscillation mode; the identified oscillation mode is aggregated and mapped into equivalent circuit elements, a corresponding third-order circuit state matrix is constructed, and the damping ratio of each mode is determined from the characteristic value; a multi-objective optimization function is constructed with the damping ratio as an evaluation index and an influence factor is introduced, a parallel adjustable impedance is parameterized and limited in a range; a heuristic probability optimization strategy is used to search for control parameters, and the final damping control parameters are obtained and transmitted to the parallel adjustable impedance device to realize online dynamic adjustment. The method can realize multi-modal identification, physical quantity level mapping and online adaptive optimization, and improve the suppression ability of the shore power system to sub- / ultra-synchronous oscillation and the operation stability.

The invention discloses a method and system suitable for preventing oscillation misjudgment of a power system. Abnormal data are removed from monitoring data to obtain to-be-identified data; based on repetitive oscillation characteristics, zero value points and fixed value points extracted from data to be identified, eliminating system oscillation when periodic fluctuation is judged to exist through prior detection and posterior detection; when the system oscillation is not eliminated, if the to-be-identified data passes node power balance verification and voltage and current phase verification and meets a power supply constraint condition, eliminating the system oscillation; otherwise, determining that the to-be-identified data is oscillation abnormal data; calculating the similarity between the oscillation abnormal data of each device, and taking the oscillation abnormal data of which the similarity is not less than a set similarity as to-be-verified data; screening out misjudgment data from the to-be-verified data, recovering the misjudgment data, and merging the misjudgment data into the oscillation abnormal data; iterative convergence is based on the installation positions of the devices with the similarity smaller than the set similarity, the system oscillation area is determined in combination with the power grid topology, and the accuracy and reliability of oscillation judgment are guaranteed.

The invention discloses a hybrid cascade DC power transmission system time-varying subsynchronous oscillation suppression method, relates to the field of power system oscillation suppression, designs a self-adaptive wave trap based on real-time measurement data and is applied to a control link of a DC power transmission system, and oscillation suppression is realized by filtering out subsynchronous oscillation components. In order to give full play to the suppression performance of the adaptive control strategy to the greatest extent, in combination with an oscillation characteristic analysis result of the hybrid cascade direct current system, control links which may be provided with the suppression strategy are screened, and suppression strategy control parameters are optimized respectively. And the optimal installation position of the self-adaptive suppression strategy is determined by comparing the optimal oscillation suppression effects at the installation positions, so that the time-varying subsynchronous oscillation of the hybrid cascade direct-current power transmission system is effectively suppressed. The time-varying subsynchronous oscillation strategy provided by the invention is clear in principle and excellent in performance, can effectively suppress the unstable oscillation of the hybrid cascade direct current power transmission system under different working conditions, and has relatively high robustness and adaptability.

The invention discloses an online oscillation suppression method and device of a doubly-fed wind turbine generator and the doubly-fed wind turbine generator, and relates to the technical field of wind power generation. According to the method, monitoring voltage representing the voltage state of a power grid is obtained, frequency domain analysis is carried out on the monitoring voltage, the characteristics of inter-harmonic voltage in the voltage of the power grid are recognized in real time, and therefore whether the doubly-fed wind turbine generator oscillates or not is judged. And when oscillation is detected, an oscillation suppression mechanism is triggered to perform control intervention on the unit. The method does not need to depend on an accurate system model, can carry out the online detection and quick response of the oscillation of the power system under the condition of a weak power grid, overcomes the problems that the oscillation recognition is lagged and the suppression capability is insufficient in a high-proportion new energy access scene in an existing network tracking type and network constructing type control mode, and improves the reliability of the system. And the operation stability and the grid-connected reliability of the doubly-fed wind turbine generator in a weak power grid environment are improved.

The application provides a power system dominant oscillation section identification method, device and equipment and a storage medium, and belongs to the technical field of power systems. The method comprises the following steps: constructing a regional equivalent model of a target power system; obtaining phasor measurement data of equivalent generators of each regional power subsystem based on the regional equivalent model; performing multi-channel singular spectrum analysis on the phasor measurement data to obtain regional inter-area oscillation mode signals of each equivalent generator; and performing dissipation energy analysis on the regional inter-area oscillation mode signals to identify a dominant oscillation section of the target power system based on the dissipation energy. The multi-channel singular spectrum analysis is used to quickly and effectively extract regional inter-area oscillation mode signals in data, has good anti-noise capability, and can retain more useful information. The dissipation energy analysis method is used to calculate the dissipation energy of the regional inter-area oscillation mode signals, and the energy can reflect the influence of time-varying factors on the oscillation behavior of the power system, so that the dominant oscillation section can be accurately identified.

The application discloses a kind of multi-band oscillation monitoring method, system and medium for power system, belong to power system oscillation monitoring field, method includes: the active power measurement is carried out fast Fourier transform, to extract the first characteristic vector including main harmonic amplitude, main harmonic frequency and main harmonic amplitude ratio in;First characteristic vector is input first stage Gaussian naive Bayes classifier and is classified, and output oscillation type;When oscillation type is low-frequency oscillation, the active power measurement is carried out synchronous compression wavelet transform and hilbert transform, to extract the second characteristic vector including harmonic component frequency, harmonic component attenuation factor;Second characteristic vector is input second stage Gaussian naive Bayes classifier and is classified, and output the oscillation state of low-frequency oscillation.Can accurately judge low-frequency oscillation type, and judge system stability, solved the problem that each type of oscillation sample is uneven and leads to low training efficiency and low accuracy of classifier.

The invention discloses a flexible direct current power transmission system oscillation risk assessment method based on phase-space reconstruction, and belongs to the technical field of power system oscillation risk assessment, and the method comprises the steps: collecting an oscillation output signal comprising an oscillation component when a flexible direct current power transmission system is unstable, and carrying out the preprocessing of the oscillation output signal; performing phase-space trajectory reconstruction on the preprocessed oscillation output signal by adopting a time delay embedding method; on the basis of the reconstructed phase space trajectory, predicting the phase space trajectory of the oscillation output signal of the power transmission system at the next time by using a linear autoregression model as a prediction model or a prediction model representing the geometrical characteristics of the phase space trajectory on polar coordinates; and analyzing the evolution trajectory of the predicted phase space trajectory, and evaluating the oscillation risk of the power transmission system. According to the method, oscillation risk assessment and early warning are realized based on real-time measurement data, the method does not depend on accurate modeling of the system, the complexity is low, the operation cost is low, and the method has relatively high adaptability under different working conditions.

The application relates to the technical field of power system modeling analysis, in particular to a frequency-dependent impedance modeling method, device and equipment of a power transmission line and a medium. The method comprises the following steps: obtaining resistance values of the power transmission line at multiple frequency points and inductance values at the multiple frequency points; performing polynomial fitting on the resistance values at the multiple frequency points and the inductance values at the multiple frequency points; and establishing an impedance model of the power transmission line based on the obtained frequency response fitting result of the resistance and inductance of the power transmission line. Thus, by comprehensively considering the distributed parameter characteristics and frequency dependence of the power transmission line, a model capable of accurately describing the impedance characteristics of the power transmission line at different frequencies is constructed, the problem of the prior art that is limited due to the fact that only the distributed parameter characteristics of the power transmission line are simulated and the frequency dependence of the power transmission line parameters is not considered is solved, the accuracy of the impedance modeling of the power transmission line is improved, and a theoretical basis is provided for power system oscillation stability analysis.

The application provides a power system oscillation source detection method and device, and relates to the technical field of power operation and maintenance.The method comprises the following steps: determining a first phase difference of generator power data and rotating speed data based on an oscillation period, and determining whether the power system oscillation source is from a prime mover side of the generator based on the first phase difference; if yes, an alarm is given that the prime mover side has an oscillation source; if no, determining a second phase difference of calculated excitation voltage data and measured excitation voltage data based on the oscillation period, and determining an amplitude difference of the calculated excitation voltage data and the measured excitation voltage data; determining whether the power system oscillation source is from a generator excitation system side based on the second phase difference and the amplitude difference; if yes, an alarm is given that the excitation system side has an oscillation source; if no, an alarm is given that the power grid side has an oscillation source.The application can improve the accuracy, speed and applicability of power system oscillation source detection.