56 results about "Equilibrium point" patented technology

The invention discloses a PINN-based magnetic levitation vehicle nonlinear predictive control method and device and a medium, and relates to the field of rail transit, and the predictive control method comprises the following steps: S1, constructing a dynamic model; s2, learning and approaching unknown dynamic and time-varying parameters in the dynamic model by adopting a physical information neural network; s3, designing an optimization cost function meeting system input and output constraints based on the unknown dynamic state of the dynamic model predicted by the physical information neural network; and S4, constructing a step-by-step variable terminal constraint set to process input time lag. In a controller design and theoretical analysis process, a non-linear dynamic form of a system is completely reserved, and a stepping variable terminal constraint set suitable for input time delay is constructed, so that the controller can still maintain stability and dynamic performance under the condition that a system state obviously deviates from a balance point. According to the method, the operation safety and the control precision of the maglev vehicle under complex working conditions such as parameter drift and time lag disturbance are effectively improved.

The invention provides a transient stability boundary determination method and device of a network-forming converter system and a medium, and belongs to the technical field of transient stability boundary determination. The method comprises the following steps: constructing a nonlinear autonomous system model of a network construction type new energy generator group; solving all I-class unstable equilibrium points of the nonlinear autonomous system model; constructing a local stable manifold along the stable feature vector direction of the I-type unstable equilibrium point; constructing a global stable manifold of the I-type unstable equilibrium point; and combining global stability manifolds of all I-type unstable equilibrium points to form a transient stability boundary of the system, and verifying a closed state at an infinity position based on an infinity singular point theory. According to the method, through the constructed nonlinear autonomous system model, influence factors of a stability boundary and a stability domain after the system is subjected to large disturbance are researched based on a nonlinear stability manifold theory, and forms of a saddle point boundary line and a trajectory of the system at infinity are researched, so that the transient synchronization stability of the system is improved.

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 field of electric power, discloses a thermal power generating unit APS automatic start-stop full-process control method and system, and is used for solving the contradiction among safety, economy and rapidity of a traditional APS system. The method comprises the steps of establishing a differential algebraic equation system based on unit physical parameters to generate a unified model constraint set; generating a reference trajectory representing energy conversion efficiency and power in a differential flat space according to the start-stop target curve; predicting a thermal stress change rate through a fractional order differential operator based on the metal temperature to generate a safety margin instruction; generating an energy coordination correction instruction according to the Hamiltonian energy network balance point of the boiler heat storage and steam turbine kinetic energy solving port; and mapping the reference trajectory into a control instruction, integrating thermal stress constraint and energy coordination correction, and then distributing and executing. Safe and efficient start-stop control under full-process physical constraints is achieved, start-stop safety and economy are improved, and the service life of equipment is prolonged.

The invention discloses a stability constraint LQR single-rotor unmanned aerial vehicle trajectory tracking control method based on GWO-PSO optimization. The method comprises the following steps: constructing a nonlinear dynamic model of a single-rotor unmanned aerial vehicle; defining a hovering point as a unique balance point for stable work of the single-rotor unmanned aerial vehicle, and obtaining a linearization model surrounding the balance point according to the nonlinear dynamic model based on the balance point; establishing an optimization model considering model uncertainty and external interference according to the linearization model so as to design an initial feedforward feedback LQR control law based on stability constraint; taking a weight matrix Q and a weight matrix R in the initial feedforward feedback LQR control law as a group of parametric variables, and optimizing the parametric variables based on the constructed GWO-PSO hybrid optimization algorithm to obtain an optimal variable; and obtaining an optimal feedforward and feedback LQR control law according to the optimal variable, thereby realizing trajectory tracking control of the single-rotor unmanned aerial vehicle. According to the invention, the problem that the existing method is insufficient in trajectory tracking precision, anti-interference capability and robustness is solved.

The invention provides a damping characteristic analysis method, a damping characteristic analysis device and damping characteristic analysis equipment for a grid-forming type energy storage converter, and relates to the technical field of grid-connected control. The method comprises the following steps: constructing a grid-connected mathematical model of the network-forming type energy storage converter, and determining a linear state space model at a balance point; identifying dominant factors of low-frequency oscillation under set conditions according to the grid-connected mathematical model, and updating the linearized state space model into a reduced-order model; converting the reduced order model into a multi-damping path model according to the dynamic change of the virtual angular displacement under the interaction of the reference power and the output power; analyzing the influence of system parameters and control parameters on each damping path according to the multi-damping path model, determining a dominant branch influencing the total damping of the system, and determining the stability index of the multi-damping path model so as to analyze the damping characteristics of the grid-connected system of the constructed energy storage converter. And quantitatively analyzing the influence of different control parameters on the low-frequency oscillation stability of the network construction type energy storage. According to the invention, the control accuracy of the network-forming type energy storage can be improved.

The invention relates to the technical field of magnetic suspension small ball systems, in particular to an active disturbance rejection control method of a nonlinear magnetic suspension small ball system. In order to solve the problems of nonlinear dynamic instability, insufficient multi-source interference coupling suppression and hardware damage caused by limited control input of the existing magnetic suspension small ball system under the working condition of deviating from a balance point, the invention provides a novel active disturbance rejection control method of a nonlinear magnetic suspension small ball system. Comprising the following steps: 1) establishing a mechanism model of a magnetic suspension small ball system under the action of voltage; 2) constructing a third-order nonlinear dynamic differential equation of the magnetic suspension small ball system; according to the method, new control input is defined, the complexity of the controller is reduced, meanwhile, the expansion state observer is designed, the control input is designed through state feedback information, and therefore adjustment of the system is achieved, and external interference is effectively restrained.

This invention relates to a method for calculating and evaluating the stability domain boundary of a new energy power system, addressing the problem of significant conservatism in evaluating the transient synchronization stability of grid-connected and grid-connected converters in current new energy power systems. The method includes: calculating the equilibrium point of the target nonlinear system and determining the local stable manifold of the stable equilibrium point; plotting the global stable manifold of the target nonlinear system using manifold theory and accurately observing the dynamic behavior of the target nonlinear system in the global state space; further extending the proposed transient stability domain boundary calculation method to a high-dimensional phase space; and quantitatively evaluating the transient stability margin of the target nonlinear system under different faults using the Monte Carlo method. The calculation method of this invention accurately characterizes the stability domain boundary of the target nonlinear system, providing important reference value for evaluating the transient synchronization stability of new energy power systems.

The application provides a multi-inverter hybrid system transient stability boundary delineation method based on reverse integration, and belongs to the field of electrical engineering. The delineation method combines a circuit model of a grid-constructed inverter, a grid-following inverter and an infinite grid hybrid system and a virtual synchronous machine mathematical model of the grid-constructed inverter, derives a second-order differential-algebraic equation set of the hybrid system, further obtains system steady-state equilibrium points by solving the equation set and classifies, and reversely integrates from the type I unstable equilibrium point to obtain a transient stability boundary of the hybrid system. The application is simple and intuitive, has a solid theoretical basis, can quickly and accurately identify the transient stability boundary of the grid-connected inverter system, and has important significance for analyzing the transient stability of the multi-grid-connected inverter hybrid system.

The application provides a power system transient stability evaluation method and a power system operation trajectory prediction method based on a Koopman operator, the power system transient stability evaluation method comprising the following steps: S1, collecting operation trajectory data of state variables of a power system; S2, using an EDMD method to increase dimensions of the collected state variables to a high-dimensional linear space to approximate an action of the Koopman operator by using a limited-dimensional linear matrix K ; S3, using spectral decomposition of the Koopman operator to locate discrete spectra of stable equilibrium points of the power system, and using characteristics of eigenvalues of the Koopman operator and inverse mapping of dictionary functions to find stable equilibrium points of the power system in an original state space; and S4, based on the obtained stable equilibrium points and analysis of a stable mechanism of a linear system, constructing a power system transient stability criterion, and using the transient stability criterion to judge whether the system is transiently stable after the power system suffers from a large disturbance and collects an arbitrary working point.

The application provides a transient synchronous stability dominant bifurcation mode identification method for an inverter grid-connected system, and relates to the field of power systems and their automation, and the steps of the method are as follows: obtaining inverter parameters and power parameters of the inverter grid-connected system and obtaining bifurcation equivalent parameters; based on a stable equilibrium point, obtaining a Hopf complex normal form coefficient real part and a normalized bifurcation parameter according to a generalized swing equation and the bifurcation equivalent parameters; obtaining a limit cycle amplitude according to the bifurcation equivalent parameters, the Hopf complex normal form coefficient real part and the normalized bifurcation parameter; obtaining a transient stability margin according to a geometric distance between a stable manifold at an unstable equilibrium point and the stable equilibrium point; and identifying a dominant bifurcation mode of the inverter grid-connected system according to the limit cycle amplitude and the transient stability margin. The method can effectively improve the efficiency and precision of transient synchronous instability mode identification, realizes quantitative evaluation of the stability margin, and provides accurate transient synchronous stability criteria for power systems.

The present application relates to a kind of near-earth formation satellite PID passive control method, comprising the following steps: step S1, establish near-earth orbit formation port Hamilton system dynamics model;Step S2, establish passive PID controller according to dynamics model, additional system is constructed, and according to Lyapunov function demand, partial differential equation is solved;Step S3, according to the requirement of equilibrium point, design Lyapunov function, and determine additional system integral item initial value;Step S4, establish PID passive controller based on additional system integral item initial value.The present application effectively avoids the problem that PID controller parameter selection is difficult, and large-scale system performance is poor, and passive PID control method can be simply and effectively established for near-earth orbit satellite formation Hamilton dynamics system, which is beneficial to the design of controller.

The invention provides a small disturbance stability estimation method for a grid-following type and grid-constructing type hybrid grid-connected converter, and relates to the technical field of power grids, and the method comprises the steps: aiming at each preset time period, based on the corresponding control and structure parameters of the grid-following type grid-connected converter and the grid-constructing type grid-connected converter in a small disturbance scene, calculating the stability of the grid-following type and grid-constructing type hybrid grid-connected converter; determining a system stable equilibrium point, a system unstable equilibrium point and equilibrium point stability conditions corresponding to the preset time period; determining a period stability analysis result corresponding to the preset time period based on a balance point linear differential equation, the system stable balance point, the system unstable balance point and the balance point stability condition; and determining a target stability analysis result based on the period stability analysis results corresponding to all the preset time periods. The method is applied to the condition of series-parallel connection of the following grid-connected converter and the construction grid-connected converter, is not influenced by a relatively high model order of the grid-connected converter, and can obtain an accurate stability analysis result.

The application discloses a power system output differential passivity measurement method based on input-state trajectory, which comprises the following steps: S1, input state trajectory data is acquired; S2, data normalization processing is performed; S3, a linear matrix inequality constraint is constructed; based on the normalized matrix in S2, the definition of output differential passivity is extended to the form of a matrix inequality constraint; and S4, an optimal output differential passivity index is solved. The power system output differential passivity measurement method based on input-state trajectory can further check the output differential passivity of the power system and calculate an optimal output differential passivity index under the condition that the internal parameters of equipment are not dependent, the equilibrium point is not known in advance and measurement noise exists, by means of the measured input state trajectory.

The application relates to the technical field of aircraft control, and discloses an aircraft stability bifurcation analysis method considering flight state constraints, which comprises the following steps: establishing an aircraft six-degree-of-freedom nonlinear flight dynamics model, defining a system state parameter vector and a system control parameter vector, introducing a flight state constraint equation, selecting an extension parameter, constituting an extended state variable, constructing an extended bifurcation analysis model, adopting a pseudo-arc length continuation algorithm to obtain a trimming solution set and a trimming numerical mapping relationship, obtaining a physical dynamics system equation, calculating a Jacobian matrix and extracting eigenroots, judging stability and bifurcation types according to the eigenroots, and obtaining a bifurcation curve and using the bifurcation curve for flight control. The flight state constraints are converted into equivalent differential constraints and are solved together with the flight dynamics model, so that the equilibrium points obtained through the continuation calculation satisfy the flight state constraints, and the bifurcation curve is obtained in combination with the trimming numerical mapping relationship and the eigenroots, thereby providing a basis for the determination of the dynamics boundary of a dangerous flight mode.

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.

The present application relates to the technical field of network security, in particular to a network attack and defense strategy selection method and system based on three-party evolutionary game, a three-party evolutionary game model is constructed by an attacker, a defender and a user as network attack and defense confrontation participants based on evolutionary game theory, the participants of the three-party evolutionary game model imitate the advantageous strategy in the evolutionary game and adjust their own strategy selection under the driving of game income; the stability of the three-party evolutionary game model is solved by using a three-party behavior strategy selection dynamic equation, the equilibrium point of the three-party evolutionary game model is obtained, and the best selection strategy of each subject of the participants is obtained according to the equilibrium point of the three-party evolutionary game model. The present application models and describes the real attack and defense scene more accurately by constructing a game model with the participation of the attacker, the defender and the user, and provides technical support for solving the network information security problem.

The invention provides a method for depicting a transient stability boundary of a multi-inverter series-parallel system based on reverse integration, and belongs to the field of electrical engineering. According to the depicting method, a circuit model of a network building type inverter, a circuit model of a network following type inverter and an infinite power grid series-parallel system and a circuit model of a network building type inverter virtual synchronous machine mathematical model are combined, a second-order differential-algebraic equation set of the series-parallel system is obtained through derivation, and system steady-state balance points are obtained and classified by further solving the equation set. And carrying out reverse integration on the I-type unbalanced stable point to obtain the transient stability boundary of the series-parallel system. The method is simple and visual, has a solid theoretical foundation, can quickly and accurately identify the transient stability boundary of the grid-connected inverter system, and has important significance for analyzing the transient stability of the multi-grid-connected inverter series-parallel system.

The invention discloses a micro-grid linearization model order reduction method, system, equipment and medium, and belongs to the field of micro-grid stability analysis and control. Models of all elements in a micro-grid are obtained, a nonlinear differential algebraic equation set is established, a stable equilibrium point of the nonlinear differential algebraic equation set is solved, linearization processing is carried out, and a linearized differential algebraic equation set is obtained; solving a rightmost characteristic value by adopting a characteristic value algorithm, if the system is not stable, performing leftward translation transformation on the system to stabilize the system, generating a Lyapunov equation according to the translated system, solving a controllable and observable Gramb matrix by adopting a Krylov subspace algorithm, and performing order reduction on the translated system by adopting a balanced truncation method to obtain a stable system; according to the method, an existing balance truncation method is improved, the precision, the stability, the controllability and the observability of a system after order reduction are guaranteed, meanwhile, the Grubrum matrix can be efficiently solved, and the method is made to be suitable for an unstable system.

The application discloses a kind of based on KAN network and adaptive unified trajectory optimization explainable identification method and equipment, belong to artificial intelligence technical field.The method includes: using the adaptive unified trajectory optimization method of combining adaptive first-order and second-order moment and gradient amplification mechanism to carry out parameter optimization to improved Kolmogorov-Arnold deep neural network;Optimization, pseudo-transient continuation and quotient gradient system modify traditional gradient flow by a specific way, so as to amplify smaller gradient, and accelerate the trajectory away from flat area or saddle point area, so as to improve the stability of training and reduce the possibility of falling into local minimum;The method of introducing pseudo-time continuation is used to quickly determine the steady-state solution of differential equation during network training;Adaptive updating technology is used to update pseudo-time step.The application converts KAN training problem into finding stable equilibrium point by constructing quotient gradient system, and realizes fast and robust convergence.

The invention discloses a new energy automobile charging mode analysis method based on an evolutionary game theory, and the method comprises the steps: firstly, determining a government, an automobile manufacturing enterprise and a consumer as game participants, and defining a strategy set and influence factor variables of the game participants; based on this, a payment matrix coupling benefits of three parties is constructed, and then a replication dynamic equation is established by taking the strategy selection probability of each party as a state variable; a system equilibrium point is obtained by solving an equation, stability analysis is carried out by using a Jacobian matrix eigenvalue method, and a stability condition for enabling the equilibrium point to become an evolution stability strategy point is deduced; and finally, based on the condition analysis, factor variables needing to be adjusted for realizing the expected stable strategy are analyzed, and a decision support result is generated. According to the method, the defect that the prior art lacks a dynamic view angle, a system framework and a quantitative model is overcome, the three-party strategy interaction evolution process can be quantitatively depicted, the stability condition is determined, and a scientific and quantitative basis is provided for industrial policy making and enterprise strategic decision making of a battery charging and replacing mode.

The invention relates to an electricity-carbon-green certificate market balanced scheduling method based on a multi-agent evolutionary game, and the method comprises the following steps: 1, collecting data, and constructing an electricity-carbon-green certificate three-market double-layer coupling model; 2, carrying out multi-agent modeling, and modeling a power generation enterprise, a power user, a renewable energy enterprise and a supervision mechanism into a multi-agent model; 3, performing evolution modeling on the intelligent agent strategy by adopting a replicated dynamic equation, and constructing an evolutionary game model; 4, a multi-agent near-end strategy optimization algorithm MAPPO is introduced, a multi-agent reinforcement learning model is constructed, and all agents are trained under a'centralized training and distributed execution 'framework; and step 5, after training convergence, outputting an optimal strategy set of each market subject, and obtaining an equilibrium point of the power-carbon-green evidence coupling market. According to the method, the limitation that a traditional method depends on complete rationality and analytical solution is broken through, rapid convergence and stable equilibrium of the complex coupling market are achieved, and the method has remarkable engineering value and policy guidance significance.

The invention relates to an inverter grid-connected parameter stability domain identification method and device based on bifurcation characteristics, and the method comprises the steps: building a generalized swing equation based on differential algebraic equations of different inverters; deducing a unified standard form and equivalent parameters suitable for bifurcation analysis; systematically analyzing boundary conditions of generalized saddle node bifurcation, Hopf bifurcation and homoclinic bifurcation, and constructing region division with different dynamic behaviors in a parameter space; and based on system balance points and manifold characteristics in different regions, and in combination with a Melnikov function analysis result, stability domains under inverter control parameters and electrical parameters are accurately identified. According to the method, a nonlinear dynamics principle is utilized, bifurcation boundary conditions of an inverter grid-connected system are deduced, typical areas with different dynamics structures in a parameter space are constructed, parameter stability domains under different operation working conditions are further identified, the multi-parameter stability problem of a complex system can be reduced to boundary judgment of a few key parameters, and the stability of the inverter grid-connected system is improved. And the stability domain identification efficiency and precision are greatly improved.

The application discloses a calculation method of a variable-ellipse set model switching predictive control with constraints, and belongs to the technical field of industrial automatic control. The method is as follows: a first equilibrium point is selected; a linear submodel at the first equilibrium point is obtained; a neighborhood which can be approximated by the equilibrium point corresponding linear submodel is estimated, and output saturation constraints are obtained; control input saturation constraints are set, and the maximum feasible ellipse set of the subsystem is estimated; the initial state of the maximum feasible ellipse set is judged; an optimization problem is solved in the maximum feasible ellipse set, the state feedback matrix of the subsystem at the k moment is obtained, and a state feedback controller is designed in the maximum feasible ellipse domain. The application solves the problem that the neighborhood estimation algorithm cannot guarantee that the neighborhood is a convex set, and can effectively reduce the system conservativeness. By using the variable-ellipse set model switching predictive control algorithm, the state feedback control law is used to replace the free variable in the system switching process, and the calculation amount of the system is reduced.

The invention discloses a virtual synchronous machine parameter optimization method and a related device, and belongs to the field of power system control parameter optimization, and the method comprises the steps: firstly obtaining a related model and parameters of a virtual synchronous machine, and building a differential algebraic equation representing the dynamic characteristics of a micro-grid before disturbance; then solving a stable equilibrium point, carrying out linearization processing on the differential algebraic equation at the equilibrium point to obtain a small-interference stability analysis model, and solving a characteristic value and a damping ratio of the small-interference stability analysis model; determining a micro-grid model after large disturbance and disturbance removal, and performing transient stability evaluation; and finally, constructing an objective function and a constraint condition of parameter optimization considering small interference and transient stability, and obtaining an optimized inertia coefficient and a voltage integral coefficient. In addition, the damping coefficient and the reactive droop coefficient are determined according to the requirements of the micro-grid for the variation range of the frequency and the voltage and economic operation. According to the method, the micro-grid can be ensured to have relatively good small-interference stability and transient stability at the same time.

The application relates to the technical field of aircraft flight dynamics, and discloses a long-endurance unmanned aerial vehicle stability analysis method considering wing flexible deformation, which comprises the following steps: establishing wing flexible deformation structure dynamics and flight dynamics coupling equations; based on the coupling equations, solving an initial accurate equilibrium point according to a Newton-Raphson iteration method; based on the initial accurate equilibrium point, solving a parameter variation equilibrium curve according to a pseudo-arc length continuation method; and based on the parameter variation equilibrium curve, establishing a bifurcation diagram according to a bifurcation theory to analyze long-endurance unmanned aerial vehicle global stability. The long-endurance unmanned aerial vehicle stability analysis method considering wing flexible deformation can deeply analyze system nonlinearities and coupling properties and the like by establishing structure dynamics and flight dynamics coupling nonlinear dynamics equations considering wing flexible deformation, and can clearly show global system stability changes caused by parameter variation, so that the method is more comprehensive and effective.

The application provides a control method and system of a PD controller of a double-neuron neural network model under the influence of time delay and diffusion, and the method comprises the following steps: establishing a time delay reaction diffusion double-neuron neural network model described by a partial differential equation; applying a PD controller on the basis of the time delay reaction diffusion double-neuron neural network model without control to obtain a time delay reaction diffusion double-neuron neural network model with the PD controller; obtaining a characteristic equation of a controlled network after linearization by taking the time delay reaction diffusion double-neuron neural network model under the action of the PD controller; selecting a communication time delay as a bifurcation parameter, and performing stability analysis and bifurcation analysis on the characteristic equation of the controlled network after linearization, and further selecting appropriate control parameters so that the network is locally asymptotically stable near an equilibrium point. The application can better realize the regulation and control of network stability, the control parameters are flexible to adjust, the actual operation is simple and easy to implement, and the control effect is obvious.

The invention discloses a new energy equipment low-voltage ride-through transient synchronous stability analysis method based on an improved equal-area principle. The method comprises the following steps: performing transient modeling on a new energy grid-connected system considering a complete low-voltage ride-through process; solving a stable working point of the system at the stage 1 and an unstable equilibrium point of the system at the initial moment of the stage 3; normalizing the differential algebraic equations at the initial moments of the stage 2 and the stage 3 into the form of a generalized swing equation, and solving each equivalent coefficient; at the initial moment of the stage 3, the critical cutting angle of the system is calculated through the first-time equal-area approximation principle, the second-time equal-area approximation principle and the third-time equal-area approximation principle, and the critical cutting angle of third-time approximation serves as an output result based on the improved equal-area principle; and calculating the trajectory of the new energy grid-connected system during the fault duration, and outputting the critical clearing time of the new energy grid-connected system in combination with the numerical trajectory and the analytically calculated critical clearing angle, thereby helping to take measures in time to ensure the safe and stable operation of the power system.

The invention provides a transient synchronous stability dominant bifurcation mode identification method for an inverter grid-connected system, and relates to the field of power systems and automation thereof, and the method comprises the steps: obtaining inverter parameters and electric parameters of the inverter grid-connected system, and obtaining bifurcation equivalent parameters; based on the stable equilibrium point, according to a generalized wobble equation and the bifurcation equivalent parameter, obtaining a Hopf complex regular coefficient real part and a normalized bifurcation parameter; according to the bifurcation equivalent parameter, the Hopf complex regular coefficient real part and the normalized bifurcation parameter, obtaining a limit cycle amplitude; obtaining a transient stability margin according to the geometric distance between the stable manifold at the unstable equilibrium point and the stable equilibrium point; and identifying the dominant bifurcation mode of the inverter grid-connected system according to the limit cycle amplitude and the transient stability margin. The method can effectively improve the efficiency and precision of transient synchronization instability mode recognition, achieves the quantitative evaluation of the stability margin, and provides a precise transient synchronization stability criterion for a power system.

The invention belongs to the technical field of passive control, and particularly discloses a control method and device of an MMC passive controller, equipment and a medium. Obtaining electrical data, and processing the electrical data through the Kirchhoff's law to obtain a single-phase voltage current equation; generating an MMC mathematical model according to the single-phase voltage and current equation; the MMC mathematical model is converted into an Euler-Lagarange model, and the Euler-Lagarange model is converted into Setting an expected balance point, calculating a state variable error according to the expected balance point, and substituting the state variable error into the Euler-Lagarrange model to calculate a passive control law; and generating a control formula according to the passive control law, wherein the control formula is used for controlling the MMC passive controller. According to the method, the MMC mathematical model is established on the basis of the electrical data and is converted into the Euler-Lagarrange model to improve the model accuracy, the passive condition is met by introducing the expected balance point, the asymptotic stability of the closed-loop system near the balance point is realized, an objective function does not need to be established, and the calculation is simple.