70 results about "Transient stability analysis" patented technology

The invention relates to the technical field of new energy grid-connected control, in particular to a fault stage transient stability analysis method and system for a following-constructed network type converter series-parallel system, and the method comprises the steps: enabling a constructed network type converter to be equivalent to a controlled voltage source series impedance, enabling a following network type converter to be equivalent to a controlled current source, and enabling the controlled current source to be equivalent to a controlled voltage source series impedance; the whole series-parallel system is equivalent to a scene in which double voltage sources and a single current source are jointly connected in parallel to a PCC point, and a series-parallel system model is constructed; according to the series-parallel system model, respectively representing an active power coupling term of the network-building type converter and a voltage coupling term of the network-following type converter under the condition of considering parallel connection of the network-following type converter and the network-building type converter; according to the coupling term, remodeling an active loop control structure of the network-constructing converter and a phase-locked loop synchronization structure of the network-following converter, and obtaining a transient analysis model of the series-parallel system considering the coupling term; the transient stability of the hybrid system in the power grid fault stage is analyzed through the transient analysis model, and the influence on the transient stability is effectively represented.

The invention discloses a transient stability analysis method for a network-building type energy storage inverter based on torque enhancement control. The transient stability analysis method comprises the following steps: step 1, constructing a network-building type energy storage inverter model based on torque enhancement control; step 2, transient stability analysis of the net-building type energy storage inverter: 2.1, an energy function method, 2.2, influences of parameters on an attraction area, and taking a damping coefficient, line impedance and reference active power which influence a swing equation as variables, so as to obtain the transient stability of the net-building type energy storage inverter; transient power angle instability of the network-building type energy storage inverter is essentially caused by imbalance between the reference active power and the output active power, and the transient stability margin can be improved by reducing the reference active power during the fault period. The method has the beneficial effects that the problems of active power fluctuation and voltage instability of the grid-forming type energy storage inverter are considered, so that the fluctuation can be effectively suppressed and the oscillation can be reduced when the voltage of the system is suddenly changed.

The invention discloses a series-parallel system transient stability analysis and fault ride-through control method considering current limiting, and belongs to the field of power fault analysis. In order to reveal an action mechanism of a current amplitude limiting and converter coupling effect on the transient synchronization stability of the hybrid system, the method comprises the following steps: firstly, considering the influence of control mode switching of a constructed network type converter, and establishing a transient analysis model of the hybrid system considering a current amplitude limiting link; then, based on a phase plane method, analyzing an action rule of converter control parameters on system transient stability, determining an optimal active power reference value and a saturation current phase angle of the grid-forming converter during a fault period, and proposing a fault ride-through control strategy according to the optimal active power reference value and the saturation current phase angle; and finally, verifying the correctness of theoretical analysis and the effectiveness of the proposed control strategy through multi-working-condition simulation.

The invention provides a transient stability analysis method for a grid-connected system. The method comprises the following steps: establishing a mathematical model of a heterogeneous new energy grid-connected system comprising a network construction type new energy unit, a network following type new energy unit, a synchronous generator and a receiving end power grid, and defining a state variable set of the system; solving a stable equilibrium point and an unstable equilibrium point of the system according to the operation condition of the system; and by taking the unstable equilibrium point as a starting point, calculating by adopting a numerical integration method or a numerical continuation method to obtain a stable manifold starting from the unstable equilibrium point. The method provided by the invention realizes global and accurate depiction of the transient stability domain, overcomes the defects that a traditional small signal linearization method can only analyze local stability and a traditional energy function method depends on an artificial construction function and is limited in applicability, fundamentally changes an analysis normal form of the transient stability domain, and improves the analysis accuracy of the transient stability domain. And a more effective analysis tool is provided for safe and stable operation of the high-permeability new energy grid-connected system.

The invention relates to the technical field of converter analysis, in particular to a converter transient stability analysis method and system considering HPFR structure influence. The method comprises the steps that an HPFR structure is considered, and a transient response large disturbance dynamic model of a virtual synchronous generator under large disturbance is constructed; based on the constructed transient response large-disturbance dynamic model, analyzing the transient stability of the system by adopting an extended equal-area method to obtain a VSG dynamic response characteristic jointly influenced by a gain coefficient and a cut-off frequency in a speed regulation link; based on VSG dynamic response characteristics, a phase diagram analysis method is adopted to evaluate a gain coefficient and a cut-off frequency in a speed regulation link, and a value interval of the gain coefficient and the cut-off frequency in the speed regulation link is obtained; and optimizing a gain coefficient and a cut-off frequency in a speed regulation link of the virtual synchronous generator, so that a power angle value of the system is smaller than a power angle value of the system tending to be unstable under a fault condition. The method has the characteristics of high analysis precision, difficulty in conservative judgment result and the like.

The invention discloses a transient stability analysis method, device and system for a new energy power system, and belongs to the technical field of new energy power generation, and the method comprises the steps: setting a network-type converter of the new energy power system as a voltage source in a normal state, and switching the network-type converter into a current source in a fault state; and representing a first transient analysis model corresponding to the grid-forming converter and a second transient analysis model corresponding to the grid-forming converter by using a curved surface, thereby determining respective power angle stable regions of the two converters, analyzing actual power angles of the new energy power system when different power grid voltages drop, observing power angle swing tracks of the converters, and calculating the power angle stability of the new energy power system. And therefore, transient weak converters corresponding to different power grid voltage sags can be accurately reflected. Compared with the prior art, the method can accurately describe the power angle stable areas of the grid-forming converters, simulates the new energy power system under various fault conditions, provides a powerful basis for preventing system instability in advance, and improves the operation reliability of the new energy power system.

The invention discloses a method for analyzing transient stability of a hybrid synchronous control grid-forming inverter considering damping influence, and belongs to the field of DC / AC converters, the method comprises the following steps: dividing a power angle interval to be analyzed into a plurality of sub-intervals, constructing an explicit damping-power angle function in each sub-interval, further quantifying the damping influence, and calculating the transient stability of the hybrid synchronous control grid-forming inverter. And depicting a transient stability boundary of the network-constructing inverter system. According to the method, the damping influence is quantified, the defect that a traditional equal-area method is too conservative is overcome, meanwhile, compared with a traditional transient stability analysis method needing iteration, the method does not need to solve a nonlinear differential equation through complex numerical iteration, an explicit transient stability boundary can be obtained, and the method is suitable for being used for transient stability analysis. And the method is also used for the grid-forming inverter with droop control and virtual synchronous machine control of a linear damping item, and an effective method with high analyzability and low complexity is provided for transient stability analysis of the grid-forming inverter. And the method has good practical application value.

The invention relates to a multi-mode seamless switching control method of a PCS energy storage converter and related equipment, and the method comprises the following steps: collecting the current operation state parameters of the PCS energy storage converter; obtaining a potential switching mode corresponding to a mode switching trigger condition based on a matching relationship between the current operation state parameter and the preset mode switching trigger condition; performing transient stability analysis on the PCS energy storage converter based on the potential switching modes to obtain a transient response characteristic curve of each potential switching mode; performing priority ranking on the potential switching modes based on the transient response characteristic curve to obtain a switching priority sequence; and performing multi-mode seamless switching control on the PCS energy storage converter on the basis of the switching priority sequence, thereby solving the technical problem that in a multi-mode PCS control strategy, dynamic sensing and analysis capability for a real-time operation state is lacked, so that a switching decision is lagged or misjudged.

The invention relates to the technical field of power system safety assessment, and discloses an optical storage and charging micro-grid power distribution network safety assessment method, system and device based on continuous loading capacity assessment and a medium, and the method comprises the steps: building a probability distribution model of an optical storage and charging micro-grid through data preprocessing; calculating a continuous loading capacity index considering the time sequence characteristics; establishing a power flow model of the power distribution network, and performing voltage, thermal and transient stability analysis; carrying out probability safety evaluation by adopting Monte Carlo simulation; and optimizing the acceptance capability of the optical storage and charging micro-grid based on the security constraint. Accurate and efficient evaluation of the safety level of the power distribution network is achieved, and effective technical support is provided for safe operation of the power distribution network under high-proportion new energy access.

The invention relates to the technical field of electric power system transient state analysis, in particular to a double-high-characteristic electric power transient state stability analysis method, system and device and a medium. The nonlinear part of the model is limited in an adjustable neighborhood of a given balance point so as to construct a Lyapunov function; the estimation of a Lyapunov function time derivative is improved by introducing a non-uniform limiting condition, and the conservative property is reduced; meanwhile, the construction of the Lyapunov function and the lower limit estimation of the fault clearing time are subjected to collaborative optimization, so that more accurate fault clearing time estimation is obtained; according to the method, the optimal Lyapunov function and parameters are solved by using the semi-definite programming problem, the method effectively adapts to the complex dynamic characteristics of high-proportion renewable energy and power electronic equipment, and the transient stability analysis precision and reliability of a power system are improved.

The invention relates to the technical field of power grids, and discloses a power system transient stability simulation sample generation method and device, and the method comprises the steps: obtaining initial samples of a power system in different operation scenes, and the initial samples comprise initial feature vectors and transient stability quantitative indexes; extracting a steady-state feature vector and a preset fault vector in the initial feature vector; based on the steady-state feature vector and the transient stability quantitative index, determining a generation sample type of a sample needing to be generated; determining a preset fault type of the sample needing to be generated based on the preset fault vector; inputting the generated sample type and the preset fault type into a preset generator model, and generating a corresponding first transient stability simulation sample; and combining the first transient stability simulation sample with the initial sample to obtain a second transient stability simulation sample. According to the method, the required transient stability simulation sample of the power system can be generated in a targeted manner, and reliable high-quality sample data is provided for transient stability analysis of the system.

The invention provides a method, a system, a medium and equipment for determining the maximum direct current feed-in power of a receiving-end power grid, and relates to the technical field of transient stability analysis of an electric power system.The method for determining the maximum direct current feed-in power of the receiving-end power grid comprises the steps of obtaining a voltage dynamic response parameter after the receiving-end power grid breaks down; according to the voltage dynamic response parameters, whether the transient voltage of each bus of the receiving-end power grid is stable or not is judged; under the condition that the transient voltage of each bus of the receiving-end power grid is determined to be stable, the maximum feed-in power of the receiving-end power grid is determined, the method can flexibly adapt to variable operation conditions, and the applicability is high; and under the condition that the transient voltage of each bus of the receiving-end power grid is determined to be stable, the maximum feed-in power of the receiving-end power grid is calculated, so that a scientific basis is provided for safe dispatching and operation of a power system.

The application discloses a transient stability prevention control measure generation method and a related system, including the following steps: in a predicted fault scenario, a machine learning model is used to predict the transient stability of the current operation mode of a power system, the input of the machine learning model including various electrical characteristics related to the transient stability of the power system; the operation mode predicted as unstable is taken as an explained sample, a model explanation method is used to determine the influence degree of each electrical characteristic in the explained sample on the transient stability; candidate control units are determined according to the influence degree, and the candidate control units are adjusted, and the machine learning model is used to predict the transient stability of the adjusted operation mode until an operation mode predicted as stable is obtained, so that transient stability prevention control measures are generated. The method improves the explainability of the data-driven transient stability analysis model, the overall scheme requires a short time, and is suitable for online application.

The present invention provides a transient stability prevention and control method and device based on an agent model, the method comprising: inputting multiple operating data of an electric power system into a pre-built transient stability analysis model, obtaining transient stability analysis results of each operating data output by the transient stability analysis model, wherein each operating data includes the initial active power of a generator; determining transient instability operating data based on the transient stability analysis results, and calculating the sensitivity of each generator in the transient instability operating data by an integral gradient algorithm; and determining an adjustment strategy for the initial active power of each generator based on the sensitivity; the present invention provides a feasible solution to problems such as monitoring the stability status of the electric power system and control decision-making after instability, further improving the safe and stable operation capability of the electric power system, and providing support for preventing large-scale accidents in the power grid.

The application discloses a network-constructing type VSC transient stability analysis method and system considering internal ring dynamic influence, and comprises the following steps: determining the control system of GFM-VSC, determining active power and virtual power angle based on virtual synchronous power outer ring control; determining port node voltage phase and internal potential amplitude based on the active power and virtual power angle; determining the output current amplitude of GFM-VSC based on the internal potential amplitude and virtual power angle; determining whether the saturation link of GFM-VSC is triggered based on the internal potential amplitude and output current amplitude, and determining the saturation link type when it is determined that the saturation link is triggered; and analyzing the transient stability according to the saturation link type.

The invention discloses a power distribution network state detection method and device and a nonvolatile storage medium. The method comprises the steps that real-time operation information of a target power distribution network is acquired, and the real-time operation information comprises fan real-time generated power, photovoltaic unit real-time generated power and electric vehicle real-time charging data; the real-time operation information is input into a preset target state detection model, a state detection result of the target power distribution network is obtained, the target state detection model is obtained based on training of an initial state detection model, and the initial state detection model is a convolutional neural network model; the state detection result comprises a safety state, a warning state, a general emergency state or a serious emergency state. According to the method, the technical problems that the real-time operation state of the power distribution network is inconvenient to identify and the accuracy is reduced due to the fact that transient stability analysis of the security domain and the stability domain is separated in a traditional method, and the source load fluctuation and the uncertainty thereof cannot be effectively handled are solved.

The invention relates to a power system Lyapunov function construction method, device and equipment based on an induction motor, and the method comprises the steps: obtaining the electric quantity data of all generator sets in a power system, and obtaining the stable balance data of the power system in a stable balance state; performing model construction according to the electrical quantity data to obtain a transient stability analysis model of the power system; converting the transient stability analysis model according to the stability balance data to obtain a power flow equation; obtaining trigonometric function data and state data from the power flow equation; and according to the trigonometric function data, determining whether to construct according to the state data and the trigonometric function data, and obtaining a Lyapunov function of the power system. According to the method, the power flow equation is constructed by acquiring the electrical quantities and the stability balance data of all the generator sets in the power system, and the Lyapunov function for constructing the power system is determined according to the trigonometric function data and the state data of the power flow equation, so that the accuracy and the applicability of function construction are improved.

The application discloses a kind of transient stability analysis method and related device considering current limit, establish the mathematical model of hydropower system and photovoltaic power generation system;In view of the current-limiting control of photovoltaic inverter and flexible rectifier during fault, the equation of active power sent by hydro-generator before fault removal is derived according to Thevenin theorem;The analytical expression of critical removal angle of sending-out system is derived by using equal-area rule;With critical removal angle as the key index of transient stability limit of sending-out system, the influence of photovoltaic and flexible current transformer saturation current angle parameter value and water-light generation ratio on the transient stability of sending-out system is evaluated.The water-light generation ratio setting method involved in the application can effectively improve the transient stability of the system, and the research results are expected to provide certain theoretical guidance for the stable operation of future new energy power system.

The invention discloses a power grid stability analysis and evaluation method based on artificial intelligence, and the method comprises the steps: obtaining sample data, and dividing the sample data into training data and test data according to a preset proportion; establishing a power grid stability analysis model according to the convolutional neural network and setting model parameters; inserting an extrusion excitation module into the convolutional neural network, and adjusting the weight of the feature channel to optimize the power grid stability analysis model; training a power grid stability analysis model by adopting the sample data and the corresponding annotation data; and analyzing the power grid operation data based on the trained power grid stability analysis model, judging whether the power grid is stable or not, and predicting the instability mode of the power grid. According to the method, the artificial intelligence technology and the power grid stability analysis are combined, the defects of a traditional method in the aspects of alternating current power flow reduction accuracy, transient stability analysis efficiency, steady-state operation risk identification, optimization decision automation and the like are effectively overcome, and the accuracy and efficiency of power grid stability analysis are remarkably improved.

The invention relates to the technical field of transient stability analysis of a power system, in particular to a transient stability evaluation method and device for a wind turbine generator, and the method comprises the steps: constructing a full-order model of a control loop of a to-be-evaluated wind turbine generator, and carrying out the transient stability analysis of the full-order model of the control loop; and performing simulation aiming at different voltage sags, different phase-locked loop control parameters, different power grid line impedances and different grid-connected point d-axis current instructions of the to-be-evaluated wind turbine generator, and performing simulation verification on the transient stability of the to-be-evaluated wind turbine generator. According to the derived maximum estimation attraction domain and the property thereof, the transient stability quantitative evaluation index capable of intuitively reflecting the initial state of the transient process of the new energy unit and the boundary of the maximum estimation attraction domain is constructed, and the relationship between the evaluation index value and the state quantity change of the transient process of the unit is qualitatively and quantitatively analyzed; and the transient stability margin of the unit is quickly and visually reflected.

The present disclosure provides a multi-device transient interaction analysis method of a new energy through flexible direct transmission system, relates to the technical field of new energy power system transient stability analysis and discrimination, and comprises the following steps: constructing a system nonlinear mathematical model; constructing a differential equation of the system based on the system nonlinear mathematical model, constructing an objective function to obtain a non-steady equilibrium point of the differential equation; determining a dominant non-steady equilibrium point of the system under fault based on the non-steady equilibrium point; calculating participation factors of different state variables to the dominant non-steady equilibrium point based on the dominant non-steady equilibrium point and a Jacobian matrix of the system; quantitatively analyzing the participation degree of different links or devices in the transient dynamic of the system according to the size of the participation factors, determining the links or devices of dominant transient synchronization, and quantitatively analyzing the interaction size between different links or devices. The present disclosure can practically improve the quantitative calculation ability of the multi-device transient interaction strength of the new energy through flexible direct transmission system.

This invention relates to power electronics technology, specifically to a method for transient stability analysis of multi-inverter systems based on a two-layer iterative equal-area method. The method involves establishing a mathematical model of a multi-grid-connected inverter parallel system, defining the equivalent mechanical power, electromagnetic power, other-machine electromagnetic power, electromagnetic interaction power, and self-damping and mutual damping of the system. First, non-integrable terms are scaled down to make them integrable. Then, using the proposed two-layer iterative equal-area method, the upper and lower boundaries of the power angle stability of the multi-grid-connected inverter parallel system are obtained through two iterations. This method, by combining iteration and scaling, improves the conservatism of the stability region estimate as much as possible without causing stability misjudgments. Using the two-layer iterative equal-area method, a relatively accurate estimate of the stability region of the grid-connected inverter parallel system is obtained, improving the conservatism of the original equal-area method applied to VSC parallel systems. It has good development potential and room for promotion.

The invention relates to the technical field of converter control, discloses a converter control parameter optimization method and system based on an improved particle swarm, and adopts a two-stage architecture of offline optimization and online parameter configuration. An offline optimization stage: in the offline stage, firstly setting key parameters of an improved particle swarm, and initializing the number of iterations and the particle swarm; calculating a particle fitness value through a dual-objective function reflecting dynamic response performance and stability robustness, and solving an individual / global extreme value, a related vector mean value and a distance to determine an individual extreme value for updating; updating the particle speed and position; then simulating a disturbance condition to perform transient stability analysis, calculating a converter state variable and judging whether a system constraint is out of limit or not; the particle inertia factor weight and the particle historical optimal fitness value are updated; if not, iteration is repeated, and if yes, the optimal control parameter combination is output. The optimal parameters are configured to the converter control system in the online stage, the parameter setting problem is efficiently and reliably solved, and stable operation of the system under the complex working condition is guaranteed.

The invention relates to a tracking-networking type hybrid system transient stability analysis method considering the influence of power coupling and current amplitude limiting, and belongs to the field of grid-connected control technology and system stability analysis. The method comprises the following steps: establishing a tracking-constructing network type converter hybrid system transient analysis model considering current amplitude limiting, introducing a global sensitivity analysis method, quantifying the contribution rate of each variable to the system response variance under the action of multi-parameter coupling, and realizing sensitivity identification of key parameters; based on a power angle characteristic curve and an expansion phase diagram theory, performing qualitative and quantitative analysis on transient response characteristics of the GFM converter in the whole fault process, and revealing a dynamic mechanism of the GFM converter; on the basis of an equal area rule, reasonable approximation is carried out on a damping effect, transient stability calculation is carried out on an established switching system, and a limit cut-off angle of the GFM under the influence of damping and power coupling is obtained through derivation. The method has accuracy and effectiveness under the conditions of different parameter settings and different faults.

The application provides a kind of ship PPL power supply system transient power angle trajectory and stability boundary calculation method, belong to ship power system transient stability analysis technical field, including the construction containing PPL ship power system period variable step length variable order Dormand-Prince analytical model, transient power angle phase space trajectory is described;Constitute Lyapunov periodic index as the criterion of the convergence of system period time-varying state variable, extract state trajectory characteristics and identify the convergence stability, sub-stable and divergent unstable region boundary of system parameter;Based on the criterion, a parameter sensitivity calculation method is proposed, and the multi-time scale parameter characteristics of the system transient phenomenon are quantitatively analyzed.The application adopts the above-mentioned ship PPL power supply system transient power angle trajectory and stability boundary calculation method, which overcomes the limitation of the existing method in dealing with the complex pulse load dynamic characteristics and nonlinear behavior of ship power system, and provides a technical solution for the safe and stable operation of ship power system under pulse load impact.

The invention discloses a grid-connected VSG transient stability analysis method considering high-order nonlinear interaction of a control loop, and the method comprises the following steps: S1, considering the high-order nonlinear interaction between an active control loop and a reactive control loop, and building a time domain separation model of a three-order VSG system; s2, simplifying the model obtained in the step S1 into a second-order swing equation, performing integral replacement, and converting a dynamic relationship among a synchronous loop output amplitude, a virtual power angle and a derivative of the virtual power angle relative to time into an algebraic relationship; s3, obtaining a high-order iteration equal-area rule iteration process, and calculating a corresponding distribution function; and S4, a VSG system transient synchronization stability criterion is explained, the influence of the DRPL is ignored, and a stability evaluation result is obtained. The invention provides a novel high-order iteration equal-area regularization method, dynamic coupling between an active control loop and a reactive control loop is considered, and the method can be used for processing transient stability of a third-order nonlinear grid-connected VSG system.

The application discloses a kind of based on VSC-HVDC AC-DC system transient stability analysis method, first constructs the steady-state model and transient model of AC-DC system based on VSC-HVDC, determines stable equilibrium point before and after fault, then constructs the energy function of AC-DC system based on VSC-HVDC, and based on fault trajectory, determine the maximum value of system energy, as escape point, take escape point as initial value, based on stable boundary tracking determines the norm of reduced system integral process, find out the norm minimum point, take norm minimum point as initial value to determine leading unstable equilibrium point, finally determine the energy at leading unstable equilibrium point, and the energy of this point is as critical energy, determine system limit cut-off time, complete AC-DC system transient stability analysis.The scheme of the application can determine the minimum gradient point and leading unstable equilibrium point in the transient stability analysis of AC-DC system containing VSC-HVDC, improve the precision of direct method transient stability analysis, and is beneficial to the stability of flexible HVDC transmission system.

The invention discloses an active support control method, system, device, medium and product under a dynamic fault condition, and the method comprises the steps: obtaining the operation data of a plurality of types of resources in a power grid, obtaining the fault operation data of a grid-connected point when the power grid breaks down, and recognizing the fault type of the power grid according to the fault operation data; performing power grid transient stability analysis according to the operation data and the fault type of each type of resource, determining the power adjustment amount of each type of resource, taking the operation data and the fault type of each type of resource and the power adjustment amount of each type of resource as mapping samples, constructing a training sample set, training a convolutional neural network, and obtaining a training sample set; the method comprises the steps of obtaining a power adjustment prediction model, inputting operation data and fault types of various types of resources in a current calculation time period of a power grid into the power adjustment prediction model, and adjusting the power of various types of resources according to the power adjustment prediction quantity of various types of resources, thereby effectively performing cooperative control on multiple types of resources.

The invention provides a transient voltage stability index analysis method based on a Gaussian-Legendre algorithm, and belongs to the technical field of transient stability analysis of alternating current and direct current systems. The technical problem that the relation between the transient voltage stability and the direct-current transmission power of the alternating-current and direct-current system is difficult to quantify and analyze is solved. According to the technical scheme, the method comprises the following steps of 1, proposing a polynomial approximation method of a transient voltage stability index; 2, selecting a proper primary function to construct a polynomial approximation model; 3, solving a coefficient of a polynomial through a Gaussian-Legendre quadrature method; and step 4, based on a segmented approximation strategy, determining the order of each segment of polynomial, and dynamically adjusting the order of the approximation model according to the change rate of the power grid voltage response. According to the method, polynomial approximation is carried out on the transient voltage stability margin, and the stability performance of the power grid under different operation conditions is quantified in real time.

The invention discloses a transient stability analysis method for a direct-current bus voltage synchronous grid-forming type converter, relates to the technical field of power electronics, and solves the problem that real-time changes of inertia and potential along with frequency in a converter cannot be accurately described due to constant parameters of an existing transient stability analysis method for the grid-forming type converter. According to the method, nonlinear characteristics of variable inertia and variable internal potential are completely fused into an energy conservation framework for the first time, then explicit expressions of kinetic energy, potential energy and damping work are analyzed and derived, and then an implicit stability boundary equation is solved by adopting an iterative algorithm; by fully utilizing the negative feedback convergence characteristic that the frequency-dependent inertia coefficient and the frequency-dependent internal potential are updated along with the state variable, the accurate capture of the critical stable frequency distribution function is realized. According to the method, constant parameter hypothesis limitation is broken through, the deviation between the theoretical evaluation result and the actual stability boundary of the system is reduced, the analysis precision is improved, and a quantifiable theoretical basis is provided for parameter optimization and robust design of the network-forming converter.