342 results about "Admittance" patented technology

The invention relates to the technical field of AC / DC module control, and discloses an intelligent control method and system for multi-mode switching of an AC / DC module. According to the method, a dynamic topology mapping model is constructed according to an impedance spectrum matrix, and a physical connection relation is converted into a node admittance relation network; generating an energy distribution state sequence based on the power fluctuation vector, and analyzing migration constraint conditions among different operation modes by adopting an association rule mining algorithm; when an operation mode switching instruction is detected, activating a node admittance relation network in the dynamic topology mapping model, and inputting a current energy distribution state sequence to an association rule mining algorithm; according to a real-time matching result of the node admittance relation network and the migration constraint condition, generating a switching control instruction containing an impedance adjustment gradient and a power distribution weight; and the power semiconductor execution unit transmits the switching control instruction to the AC / DC module. According to the method, multi-mode intelligent switching control of the alternating-current and direct-current module can be realized.

The invention discloses an impedance characteristic remodeling method, device and equipment and a medium, and is applied to the field of wind turbine generators. Wherein the corresponding rotor reference current is determined according to the electromagnetic reactive power, the active power and the corresponding power reference value; correcting the rotor current according to the rotor reference current by adopting a virtual admittance control mode, and generating a corresponding rotor voltage given value; sequentially performing differentiation, filtering and signal extraction processing on the rotor reference current and the rotor current to obtain an impedance remodeling signal; and correcting the rotor voltage given value based on the impedance remodeling signal so as to enable the corrected rotor voltage given value to serve as the control voltage of a rotor side converter in the medium-voltage doubly-fed wind turbine generator after impedance characteristic remodeling. The virtual admittance control mode and the impedance remolding signal mode are adopted to suppress the negative resistance effect of the rotor side converter in the medium-voltage doubly-fed wind turbine generator under voltage disturbance, and therefore the damping effect on external excitation in the sub-super-synchronous frequency band and the high frequency band is higher.

The invention discloses a wind power system composite oscillation suppression strategy and system based on a static synchronous compensator, and the strategy comprises the steps: firstly constructing a sequence impedance model of a GFM-STATCOM and an equivalent wind turbine generator (EWTG) based on a wind power output system containing the GFM-STATCOM; combining the impedance contribution degree beta, analyzing the interaction between the two, and determining the oscillation risk dominant factor of the sub / super-synchronous frequency band; and finally, performing frequency-band suppression: aiming at the problem of negative damping dominance of the subsynchronous frequency band GFM-STATCOM, adopting a control parameter optimization strategy based on parameter sensitivity, and reducing a reactive loop integral coefficient by increasing virtual resistance so as to reduce a negative damping range. In order to solve the problem of negative damping leading of a super-synchronous frequency band EWTG, a virtual admittance control strategy based on voltage feedforward is adopted to reduce the output impedance amplitude of a GFM-STATCOM, the leading position of positive damping of the GFM-STATCOM is enhanced, and then the negative damping of the system is eliminated. According to the invention, precise suppression of composite oscillation is realized, and the stability of a wind power sending system under a weak power grid is improved.

The invention belongs to the field of stability analysis of a grid-connected system of a grid-building converter, and particularly relates to a grid-building converter grid-connected resonance risk analysis method considering virtual impedance, which comprises the following steps: S1, establishing a three-phase time domain differential equation and simplifying the equation into a single-phase equivalent time domain model; converting into a harmonic state space model of the main circuit; s2, constructing a harmonic state space model of a control system comprising an active power control loop and a reactive power control loop; s3, introducing a virtual impedance control link, and correcting the voltage amplitude reference phasor output by the reactive power control loop; deriving an expression of a modulation signal disturbance phasor; s4, obtaining a complete frequency domain admittance model YGSC of the network construction converter considering the influence of the virtual impedance; an open loop gain TGFM of the grid converter grid-connected system is constructed; and S5, drawing a Nyquist curve based on TGFM, and carrying out resonance risk determination. According to the method, the interaction dynamic characteristics of the network building converter and the power grid under the influence of the virtual impedance can be accurately represented, and the resonance risk of the grid-connected system is evaluated.

The invention provides a system temporary overvoltage evaluation method under an asymmetric fault, and relates to the field of power systems, and the method comprises the steps: responding to a VSC grid-connected system AC fault, carrying out the equivalence of a VSC fault ride-through reactive power support strategy in a positive sequence network, carrying out the equivalence of a VSC unbalanced voltage suppression strategy in a negative sequence network, and carrying out the equivalence of the VSC fault ride-through reactive power support strategy in the negative sequence network; obtaining a single-machine equivalent model; the single-machine equivalent model is merged into a network admittance matrix, a corrected admittance matrix is constructed, and a corrected impedance matrix is solved; setting short-circuit boundary conditions, calculating short-circuit current increment of a fault point as an equivalent current source, solving voltage increment of each PCC point according to the corrected impedance matrix and the equivalent current source, and synthesizing three-phase voltage; and forming a TOV evaluation result based on the phase voltage maximum value of each PCC point, and calculating a voltage safety index according to the result. According to the invention, comprehensive analysis and evaluation of the temporary overvoltage risk of the new energy grid-connected system are realized.

The invention discloses an impedance remodeling method for a grid-connected converter, and relates to the field of fire safety, and the method comprises the steps: respectively recording a virtual impedance transfer function and a virtual admittance transfer function into a current inner loop universal controller structure under a d / q coordinate system, and obtaining a series virtual impedance control structure and a parallel virtual admittance control structure; the series virtual impedance control structure and the parallel virtual admittance control structure are subjected to time domain and frequency domain conversion to obtain a series virtual impedance Norton equivalent circuit and a parallel virtual admittance Norton equivalent circuit respectively; based on the influence of virtual impedance and virtual admittance on the converter, multiple compensation links are added in a control framework of the grid-connected converter, so that the harmonic voltage and harmonic current of a grid-connected point are reduced, and the converter operates more stably.

The invention discloses a grounding fault judgment method and system of a distribution line grounding system, a storage medium, electronic equipment and a computer program product. According to the ground fault judgment method, the ground fault judgment system determines a zero-sequence voltage abrupt change value and a zero-sequence voltage amplitude according to the collected zero-sequence voltage of the distribution line; under the condition that the zero-sequence voltage abrupt change value meets a preset zero-sequence voltage abrupt change value condition, determining a transient grounding judgment result and a zero-sequence admittance value according to the collected zero-sequence current and zero-sequence voltage of the distribution line; determining the classification condition of the zero-sequence admittance value according to the transient grounding judgment result; under the condition that the zero-sequence voltage amplitude meets a preset zero-sequence voltage amplitude condition, determining a zero-sequence admittance judgment result according to the classification condition of the zero-sequence admittance value and the zero-sequence admittance value; determining a grounding comprehensive result according to the transient grounding judgment result and the zero-sequence admittance judgment result; and determining a grounding fault condition of the distribution line according to the grounding comprehensive result and a preset grounding result condition.

The invention discloses a high-voltage direct-current cable electromagnetic transient frequency domain modeling and time domain solving method, system, medium and equipment, and the method comprises the steps: obtaining an initialization parameter of a high-voltage direct-current cable, calculating an internal impedance matrix [Zi] of a multi-layer cross-section cable body during frequency calculation, and calculating an admittance coefficient matrix of the multi-layer cross-section cable body during frequency calculation; calculating ground loop impedance [] and potential coefficient [] of the air laying cable or the direct burial laying cable, and obtaining a total impedance matrix [] and a total admittance matrix [] of the cable at the time of frequency: importing obtained multi-frequency [] and [] calculation results into a PSCAD TLine module, and realizing time domain solution of frequency domain calculation by using a vector fitting model.

The invention discloses a method for checking and evaluating a constant value of a power distribution network containing new energy, which comprises the following steps of: acquiring a description information file of electronic equipment of a relay protection device containing the power distribution network containing the new energy and an electric quantity information file of a power transmission line of the power distribution network so as to construct a power distribution network model; after setting a fault position in the power distribution network model, reading a first setting value of a relay protection device and the electrical quantity of the power distribution network, and calculating according to the electrical quantity of the power distribution network to obtain a three-sequence node admittance matrix; modifying the three-sequence node admittance matrix according to a specified fault type, and calculating a fault current value of the power distribution network according to the modified three-sequence node admittance matrix; and calculating a second setting value according to the power distribution network fault current value and the first setting value, iteratively calculating the fitness of the second setting value, and calculating a new second setting value according to the power distribution network fault current value until the fitness of the second setting value meets the requirement. According to the method, the checking efficiency is improved by automatically carrying out short-circuit current calculation, constant value adjustment and fitness evaluation.

The invention relates to the technical field of electromagnetic transient simulation, in particular to an electromagnetic transient simulation system of a power system containing multiple electronic power switches, which is characterized in that numbering and topological serial number analysis are performed on multi-switch node, resistance, inductance and capacitance parameters, and a connection mapping matrix is formed by adopting impedance conversion and admittance construction modes; a sequence structure is formed by coding control variables through a genetic algorithm, a variable sequence is constructed through switching time points and topological connection, error and duration combined evaluation is executed, an optimal combination is screened, time matrix construction is carried out after energy storage voltage and filter current are collected, and a principal component vector and a covariance projection coefficient are extracted; meanwhile, an input matrix is constructed, harmonic information is fused in a unified time step, a residual network structure is introduced to carry out time-step-by-step iterative updating processing on an initial weight, dynamic adjustment is completed in combination with residual offset calculation and local error compression in each step, and a continuous and complete reconstructed waveform is output.

The invention belongs to the technical field of resonance stability of a power system, and discloses a high-voltage reactance configuration method for improving resonance stability of the power system, which solves the precision defect caused by neglecting voltage fluctuation in traditional modeling by establishing a fan and static var generator precise admittance model considering DC voltage fluctuation. The dq admittance model of the alternating current system is obtained according to the nodes, connected to the alternating current system, of the fan and the static var generator, general calculation of dq admittance of the multi-node alternating current system is achieved, the limitation that only single-node modeling is supported in a traditional method is broken through, the complex stability problem is quantized into an optimizable amplitude margin index, and the stability of the system is improved. A clear basis is provided for resonance stability analysis, high reactance configuration is expanded from traditional reactive compensation to resonance stability active optimization, and the resonance stability design efficiency of the new energy grid-connected system is remarkably improved.

The invention provides a stability analysis method and system for a tracking and networking inverter hybrid system and a medium, and the method comprises the steps: selecting the active power of a tracking inverter and the reactive power of a networking inverter as core variables through working condition variable dimensionality reduction; determining a working condition range in combination with capacity constraint, performing discretization processing, and calculating dq components of voltage and current of an inverter port based on a discrete working condition; discrete impedance models of the two types of inverters are respectively constructed; the influence of a phase-locked loop controller, a current loop controller and a power loop controller is considered in a following network type, and the effect of a virtual synchronous controller, a current loop controller and a voltage loop controller is included in a construction network type; and calculating a closed-loop transfer admittance matrix of the power grid through the discretized impedance of the inverter to realize stability analysis of the hybrid system. According to the method, the modeling complexity is effectively reduced, the stable working areas of the system under different working conditions can be quantified, and an accurate reference basis is provided for stable operation of the hybrid inverter system.

The invention relates to a DC power transmission system oscillation suppression method based on a matrix passivity theory. The method comprises the following steps: firstly, establishing a converter admittance matrix under a frequency coupling effect; then, constructing a stability criterion of the direct-current power transmission system based on the admittance matrix of the converter in combination with a matrix passivity theory; and finally, based on the stability criterion of the direct-current power transmission system, adding active damping and passive damping, adjusting corresponding parameters, and suppressing medium-high frequency oscillation of the direct-current power transmission system. The method can solve the problem of dependence on power grid side impedance modeling, constructs the stability criterion of the DC power transmission system by directly analyzing the admittance matrix characteristics of the converter, adapts to the complex situation when the AC grid side operation condition changes, and can completely suppress the medium-high frequency oscillation of the DC power transmission system. An unstable interval of a direct current system is transferred to a high frequency band through active damping, strict stability of the direct current power transmission system in middle and high frequency bands is achieved through passive damping, and the strategy cost is reduced.

The invention discloses a virtual impedance compensation method for permanent magnet synchronous generator constant admittance modeling, and relates to the technical field of electromagnetic transient modeling of permanent magnet synchronous generators, and the method comprises the steps: firstly, carrying out the discretization of a permanent magnet synchronous generator model; secondly, decomposing the equivalent resistance matrix into a time-invariant part and a time-varying part; then, virtual impedance is added to the q axis of the generator model; thirdly, constructing a generator constant admittance model; thirdly, a converter accompanying discrete circuit model is integrated, a complete permanent magnet synchronous generator constant admittance model is formed, and a node admittance equation is established based on the Kirchhoff's current law; and finally, executing electromagnetic transient simulation. According to the method, constant admittance modeling is achieved based on virtual impedance compensation, the requirement for real-time inversion of a time-varying admittance matrix is eliminated, simulation calculation resource consumption is remarkably reduced, small errors are kept under various working conditions, and efficient simulation of a large-scale permanent magnet synchronous generator system is supported.

The invention relates to the technical field of power equipment state monitoring, and discloses a transformer oil paper insulation frequency domain response online monitoring system which comprises an interface protection module, a modulation control module, a servo balance module and a diagnosis reconstruction module. The interface protection module extracts end screen leakage current and provides overvoltage protection; the modulation control module tracks the bus voltage phase and generates broadband modulation excitation voltage; the servo balance module generates a reverse servo current through closed loop feedback, counteracts a power frequency component in a leakage current so as to maintain a virtual ground state of a measurement node, and injects broadband excitation in a superposed manner; and the diagnosis reconstruction module synchronously acquires signals, reconstructs data in combination with time sequence information, calculates equivalent complex admittance by utilizing cross-correlation demodulation, and outputs complex capacitance and a dielectric loss factor. According to the invention, the operating voltage is used as a carrier wave, strong power frequency interference is eliminated through hardware servo, and safe online excitation is realized by matching with phase chopping, so that the difficult problem of weak broadband signal extraction is effectively solved, and combined monitoring and diagnosis are realized.

The invention relates to an interconnection line parameter extraction method based on a layered medium Green function improved moment method and a program product, and the method comprises the following steps: setting a sweep frequency parameter and a layered medium structure parameter, constructing a layered medium Green function, and carrying out the calculation to obtain an approximate solution of the layered medium Green function; establishing an electric field integral equation under the layered medium, and performing discretization processing to obtain a corresponding matrix equation; and performing iterative solution on the matrix equation to obtain the overall current distribution of the model, calculating the current value and impedance / admittance value of a port, performing electromagnetic calculation in a frequency sweep mode to obtain different port parameter values, and finally obtaining a parameter-frequency curve to complete the extraction of the port parameters. Compared with the prior art, the stratified medium Green function is fused into the frame of the enhanced electric field integral equation, electromagnetic simulation calculation of the full wave band from 0 frequency to 20 GHz can be achieved, and the method has the advantage of being high in calculation and solving efficiency.

The invention belongs to the field of short-circuit current calculation, and discloses a fault analysis method based on a power network equation and a related system.Unified modeling of the overall structure of a power system is achieved by obtaining bus information of the power system and constructing a system topological relation model, and the fault analysis accuracy is improved. The adaptation difficulty caused by different system scales and different wiring modes is avoided, and the universality and the expandability of the method are improved; according to the method, an automatic processing mechanism is introduced into the calculation and decomposition of the admittance matrix, so that the positive sequence admittance matrix, the negative sequence admittance matrix and the zero sequence admittance matrix of the power system can be quickly obtained, manual derivation and gradual simplification processes are reduced, the probability of analysis errors is reduced, and the stability of a calculation result is improved; a three-sequence network equation is uniformly adopted in fault calculation to solve a framework, and a direct coupling relation between an admittance matrix and a short circuit operation condition is utilized, so that key to-be-solved quantities such as fault current and voltage can be quickly and accurately obtained, the calculation process is remarkably shortened, and the analysis efficiency is improved.

The present application relates to the technical field of energy storage systems. Disclosed are a method and apparatus for accessing an energy storage system, and a device and a medium. The method comprises: for each load node, by using a candidate operation power of a target energy storage system at each unit time as a parameter and on the basis of a voltage value of the load node at each unit time and the admittance between adjacent load nodes, calculating a voltage fluctuation value of a power grid, in the state where connection to the load node is simulated, within a target time period; by using the candidate operation power of the target energy storage system at each unit time as a parameter, calculating a power fluctuation value of the power grid within the target time period; and on the basis of the voltage fluctuation value and the power fluctuation value that correspond to each load node, determining a target access node from among the load nodes, and determining a target operation power at each unit time, such that the target energy storage system is connected to the target access node and operates at each target operation power. The present application improves the operation stability of a power grid after an energy storage system is connected.

The invention discloses an SVG multi-working-condition control parameter optimization method and system, and the method comprises the steps: calculating a system stability margin through building a new energy station single-input single-output admittance model without SVG, traversing the working conditions of a new energy station, and positioning a critical stable working condition; setting the operating condition range of the SVG and judging the stability margin of the system after the SVG is accessed to the critical stable condition of the new energy station; and calculating the impedance ratio sensitivity of the SVG-containing new energy station system, and positioning and adjusting the SVG dominant control parameters to meet the system margin target. According to the method, the impedance characteristic change of the SVG under different operation conditions is comprehensively considered, the stability margin of multiple working conditions of the new energy station containing the SVG is improved, and the broadband oscillation risk caused by interaction of the new energy station and the power grid is reduced. The method can be widely applied to wind power, photovoltaic and other new energy stations containing the SVG, a systematic solution is provided for parameter setting and stable control of the SVG in multiple operation scenes, and the stability and working condition adaptability of a new energy grid-connected system are enhanced.

The invention belongs to the technical field of electric power system maintenance optimization, and particularly relates to an electric power circuit day-ahead maintenance plan optimization method considering voltage safety and stability, which comprises the following steps of: constructing an electric power circuit day-ahead maintenance optimization mathematical model by taking minimum unit operation cost and electric power circuit maintenance cost as targets; comprising the steps of setting an objective function and constraint conditions thereof; determining a power transmission line model and an admittance matrix, and then modifying the admittance matrix by adopting a branch addition method to obtain a line switching model based on the branch addition method; and performing staged solution on the line switching model, including three stages of generation and reduction of an uncertain scene, a mixed integer linear main problem and a nonlinear sub-problem, outputting a final solution result, and taking the final solution result as an optimal day-ahead maintenance plan of the power line. According to the method, a maintenance scheme with higher feasibility and robustness is formulated through a reasonable solving strategy, and the overall safety and reliability of a power system are improved.

The invention provides a power distribution network node harmonic exceeding main cause identification method, device and system and a medium, and the method comprises the steps: building a node admittance matrix based on the node harmonic voltage and branch current monitoring data of a power distribution network, building a related equation of the harmonic voltage and an injection current, and employing a compressed sampling matching pursuit algorithm to identify the harmonic exceeding main cause of the power distribution network; solving a sparse harmonic injection current vector, and calculating a node harmonic voltage distortion rate according to a harmonic current injection value so as to judge a standard exceeding condition; through a modal analysis method, harmonic current threshold comparison and multi-frequency superposition effect analysis, identifying main factors exceeding the standard, including harmonic injection standard exceeding, multi-frequency superposition and resonance phenomena; and quantizing contribution degrees of resonance and harmonic injection, and distinguishing composite causes of harmonic exceeding. According to the method, the problem that the harmonic cause is unknown in the harmonic exceeding scene is solved, and the accuracy of the harmonic exceeding cause is remarkably improved. Through simulation and actual measurement verification, the accuracy of the method provided by the invention is verified.

The invention relates to the technical field of radio frequency filters, in particular to a 13GXBAR filter design method based on a lithium niobate film. The Euler angle of the lithium niobate thin film is subjected to simulation setting in finite element simulation software, admittance responses under different cutting angles are obtained, an admittance curve with a large electromechanical coupling coefficient and complete stray mode suppression is obtained, the tangential angle is used for simulating an electrode material, the interdigital logarithm, the interdigital distance, the thin film thickness and the metallization ratio, and an admittance curve with a large electromechanical coupling coefficient and complete stray mode suppression is obtained. The method comprises the following steps of: constructing a plurality of resonators, obtaining impedance of each resonator, obtaining material parameters of the corresponding resonator, constructing a three-dimensional force-electricity coupling model of the lithium niobate resonator, carrying out layout design on the physical model in finite element simulation software through a field-circuit coupling method, and coupling force-electricity-sound multi-physical fields to obtain an S parameter curve of the designed XBAR filter; and whether the S parameter result is consistent with the target is verified, so that the forward design of full-simulation driving is realized.

The invention provides a picoampere-level current measuring device and method with leakage estimation and digital compensation, and the device comprises an electrometer-level operational amplifier and a transimpedance feedback network which are used for converting a measured current into a voltage signal; in combination with a retaining ring conductor driven by a retaining ring buffer and an inner and outer double-layer metal shielding structure, high-resistance node leakage and external interference are remarkably reduced. The digital controller injects 5mV-50mV micro excitation into the retaining ring in a non-sampling window and detects output response so as to estimate input equivalent leakage conductance and perform online compensation; and meanwhile, environment self-adaptive correction is carried out according to a temperature and humidity-leakage admittance model. The system adopts a 24-bit analog-to-digital converter, two-stage zero-drift amplification and multi-point linearity calibration can be switched, picoampere-level current measurement with high precision, low noise and wide dynamic range is realized, and the system is suitable for the fields of high-insulation detection, light current measurement, electrochemical micro-current analysis and the like.

The invention discloses a wind power plant broadband oscillation suppression method and system based on amplitude-phase characteristic remodeling. The method comprises the following steps: respectively establishing a frequency domain impedance model of each wind turbine generator set and performing dynamic order reduction, analyzing amplitude-frequency and phase-frequency characteristics of wind power plant multi-machine parallel coupling based on the order reduction model, determining an interaction rule of a module value and a phase angle, designing additional damping control and active damping control, and determining a wind power plant multi-machine parallel coupling amplitude-frequency and phase-frequency characteristic of the wind power plant multi-machine parallel coupling amplitude-frequency and phase-frequency characteristic. A weak position of a system is positioned based on an s-domain node admittance matrix method, a function is set by taking improvement of amplitude-phase characteristics as a target and optimizing and setting control parameters for a target wind turbine generator corresponding to the position, the optimized parameters are applied to the target generator, and effective suppression of broadband oscillation is realized. According to the application, the broadband oscillation problem caused by high-proportion new energy grid connection can be systematically solved by synergistically remodeling the frequency domain amplitude-phase characteristics of the wind power plant.

The application discloses a universal numerical aggregation method and system for frequency coupling admittance / impedance, and the method comprises the following steps: determining a frequency coupling admittance model of a converter; acquiring complementary frequency sums in the frequency coupling admittance model; splitting an original network of the converter into a first network and a second network corresponding to the complementary frequency sums respectively; connecting the frequency coupling admittance model to the first network and the second network respectively, and generating a first admittance matrix and a second admittance matrix corresponding to the first network and the second network; merging the first admittance matrix and the second admittance matrix into an extended node admittance matrix; and performing coupling frequency admittance calculation on specified network nodes based on the extended node admittance matrix.

The application discloses a stability analysis method of a photovoltaic energy storage micro-grid in an islanding scenario based on system admittance characteristics, and belongs to the technical field of distributed new energy grid-connected power generation. The method comprises the following steps: determining the main circuit filter type and control structure of a three-phase inverter of a power generation unit; establishing a second-order admittance model of the inverter based on a harmonic linearization method; decoupling the second-order admittance model to obtain linear admittance models under positive and negative sequences; establishing the voltage-current relationship at a system point of common coupling based on a node voltage method according to the topological structure of the micro-grid, and obtaining a system admittance matrix; drawing the amplitude-frequency curve and the phase-frequency curve of key items in the system admittance matrix, determining the key characteristic frequency corresponding to the minimum point of the amplitude-frequency curve, and determining the stability of the system according to the positive and negative of the slope of the phase-frequency curve at the key characteristic frequency. The method can accurately analyze the stability of the photovoltaic energy storage micro-grid in the islanding operation scenario.

The application discloses a harmonic compensation and stability improvement method, system, medium and equipment, filters components of a grid voltage in a two-phase static coordinate system to obtain corresponding fundamental components; subtracts the fundamental components of the grid voltage from the components of the grid voltage in the two-phase static coordinate system to obtain total harmonic components of the grid voltage; filters the total harmonic components of the grid voltage by using multiple band-pass filters to obtain multiple harmonic components corresponding to frequencies; subtracts reference current instructions of an active power filter from the multiple harmonic components, and inputs the result as a new current reference instruction into a current controller; and based on a virtual harmonic admittance method, outputs harmonic compensation currents through current inner loop control in the two-phase static coordinate system to realize harmonic compensation on a nonlinear load with frequency coupling characteristics and suppression of harmonic compensation oscillation. The application can adapt to various complex grid environments and has relatively practical engineering application value.

The invention discloses a harmonic interaction characteristic analysis method and device based on chaotic characteristics, equipment, a storage medium and a program product. The method comprises the following steps: obtaining harmonic impedance corresponding to a plurality of harmonic sources respectively; determining series impedance and parallel admittance of the power transmission line between the first harmonic source and the second harmonic source based on a pre-constructed equivalent circuit model of the power transmission line between the multiple harmonic sources, and determining equivalent connection impedance between the first harmonic source and the second harmonic source based on the series impedance and the parallel admittance; inputting the first harmonic impedance corresponding to the first harmonic source, the second harmonic impedance corresponding to the second harmonic source, the equivalent connection impedance and the Lyapunov exponent into a preset chaotic interaction factor calculation model to obtain a chaotic interaction factor between the first harmonic source and the second harmonic source; and determining an interaction characteristic analysis result between the first harmonic source and the second harmonic source based on the chaos interaction factor. Therefore, the stability of the multi-harmonic source system is improved.

This invention proposes a simulation method and system for the current response of distribution networks based on multi-frequency coupling effects, belonging to the field of power system modeling and simulation technology. The method includes: obtaining the frequency domain admittance matrix of the distribution network; extracting the same-frequency admittance vector and coupled admittance vector; converting each admittance vector into a transfer function, and then converting the transfer function into a discrete state-space model; preprocessing the voltage input signal using dq transform to reconstruct components at specified frequencies; substituting the preprocessed voltage signal into the discrete state-space model to obtain the current response of each frequency component; solving for the optimal weighting coefficients using an adaptive weighting strategy, and linearly superimposing the current responses to obtain the real-time simulated total current response.

This invention belongs to the field of power system technology and provides a method and system for allocating capacity to grid-connected renewable energy sources under harmonic and stability margin constraints. It obtains impedance models of grid-connected and grid-connected converters, calculates the equivalent impedance of renewable energy power plants, estimates the equivalent impedance of transmission lines, and combines the two impedances to obtain a stability margin evaluation index. It also obtains the coupled harmonic admittance matrices of the grid-connected and grid-connected converters, calculates the coupled harmonic admittance matrices, and calculates a harmonic emission level evaluation index based on the harmonic distortion level at the grid connection point. The stability margin evaluation index and the harmonic emission level evaluation index are used as comprehensive evaluation indices. The allocation range of grid-connected converters is constrained, and within this constrained range, the comprehensive evaluation index for each capacity allocation is calculated. The capacity allocation is determined based on the optimal result of the comprehensive evaluation index. This invention achieves overall optimality of power plant stability margin and grid-connected power quality.