89 results about "Equilibrium point" patented technology

The invention discloses a transient optimization control method based on a parallel system of a virtual synchronous machine and a grid-following converter. The method comprises the following steps: 1, constructing a topological structure of the parallel system of the virtual synchronous machine and the grid-following converter; 2, based on the topological structure, establishing a mathematical model of a parallel system, including an active loop equation and a reactive loop equation of a virtual synchronous machine and a phase-locked loop equation of a grid-following converter; 3, constructing an equivalent circuit, a network equation and a transient analysis model of the parallel system based on the mathematical model; 4, on the basis of the equivalent circuit, the network equation and the transient analysis model, determining conditions met by respective balance points of the virtual synchronous machine and the grid-following converter by using a balance point method; and 5, when the power grid has a fault, constructing a transient optimization strategy according to a condition satisfied by the balance point so as to realize transient optimization control of the parallel system. According to the method, the control modes of a virtual synchronous machine power loop and a grid-following type converter phase-locked loop can be improved, so that the transient stability of a parallel system converter is improved.

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 discloses a fault transient current analysis method of a network-forming converter considering a power angle swing process. The method belongs to the technical field of power system fault analysis, is used for realizing accurate solution of transient current of a network-forming converter under a three-phase symmetric drop fault of power grid voltage, and comprises the following steps: firstly, constructing a power angle swing equation based on a virtual synchronous machine control strategy; taylor series expansion is carried out on an equation nonlinear term at a steady-state equilibrium point after the fault, a linear oscillation component and a nonlinear disturbance component are separated, and a power angle approximate analytical solution is derived; secondly, establishing a grid-connected current first-order differential equation containing power grid impedance based on circuit topology, and substituting the simplified power angle expression to obtain a time domain analytical expression of voltage on the power grid impedance under a three-phase static coordinate system; and finally, in combination with a solving method of a first-order differential equation and a current steady-state initial value condition, establishing a current analytical expression of the whole fault transient process.

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 discloses a transient stability control method and system for a power system with equilibrium point continuation after disturbance, and the method comprises the steps: firstly building a steady-state mathematical expression of each dynamic element, and constructing a solving model of a system equilibrium point in combination with a power network equation; then, a homotopy method is introduced, homotopy parameter values at saddle node bifurcation points are solved, and whether balance points still exist in the system or not is judged; and for the condition of system instability, further deriving the sensitivity of the fault parameter of the homotopy curve at the saddle node bifurcation point to each control variable, and optimizing the adjustment strategy of the adjustable parameter in combination with the sensitivity and the control cost. Through a systematic search method, the optimal control scheme with the lowest cost is determined on the premise that the stability margin is met, and therefore the economical efficiency and effectiveness of control measures are improved. The optimization adjustment direction of each adjustable parameter can be accurately identified, the effectiveness of a control scheme is ensured, and accurate operation is provided for stability recovery of a power system.

The invention discloses a power system optimal power flow global optimization method based on dynamic system optimal bifurcation, which comprises the following steps of: giving an optimal power flow problem, calculating a local optimal solution by adopting a local optimization algorithm, constructing a corresponding augmented quotient gradient system, and calculating the optimal power flow problem according to the augmented quotient gradient system. The local optimal solution corresponds to a conventional stable equilibrium point of the system when the penalty factor is large enough; starting from the calculated stable balance point, continuously reducing penalty factors, tracking the change of the stable balance point of the system, recording the out-of-limit information of the stable balance point until the out-of-limit is reduced and the saddle node bifurcation disappears in the tracked original stable balance point at the moment, and continuing to integrate the system to find a new stable balance point; starting from a new stable equilibrium point, penalty factors are continuously increased until the penalty factors are large enough to enable the stable equilibrium point to meet epsilon feasibility, at the moment, the stable equilibrium point corresponds to a new local optimal solution of the optimal power flow problem, the optimal solution is better than the optimal solution in the first stage until new bifurcation cannot occur, and a new local optimal solution is found; and at the moment, finding a global optimal solution of the original optimal power flow problem. According to the method, a local optimization method is helped to efficiently jump out of a current local optimal solution, a better local optimal solution is continuously searched, and a global optimal solution is finally found.

The invention relates to the technical field of super networks, and provides an improved super network rumor propagation model establishment method which comprises the following steps: step 1, establishing an SEIAR super network rumor propagation model with an opposite state according to a classical SEIR model; 2, according to a rumor propagation rule, a differential dynamics equation set is established; 3, according to the differential dynamics equation set, a rumor-free balance point of the model is calculated; 4, calculating a basic regeneration number; step 5, solving local and global asymptotic stability conditions of the balance point by using a Routh-Hurwitz criterion and a Lyapunov stability theorem; 6, a control strategy is adopted according to the rumor spreading condition. The behavior of the rumor refuter in the social network can be well described, and the dynamic influence of the rumor refuter on the rumor spreading process is disclosed.

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 method for identifying a transient dominant instability link of a new energy grid-connected system based on a CUEP participation factor, and belongs to the field of stable operation of a power system, and the method mainly comprises the steps: 1, carrying out the transient nonlinear modeling of a grid-connected system containing new energy equipment, and carrying out the linearization near a balance point, and obtaining a Jacobian matrix J; 2, calculating all unsteady equilibrium points (UEP) of the new energy grid-connected system, and finding out all I-class UEPs according to the number of positive feature roots; 3, numerically calculating an exit point (EP) of the trajectory, and identifying a dominant unsteady equilibrium point (CUEP) according to the distance between the EP and each class I UEP; and 4, calculating a participation factor of each state quantity of the system at the CUEP point to identify a dominant instability link. According to the method, the transient dominant instability link in the new energy grid-connected system can be effectively identified, and parameters are helped to be adjusted to ensure safe and stable operation of a power system.

The present invention relates to the technical field of rumor propagation prediction, and discloses a rumor propagation system modeling method under a random switching perspective, which includes the following steps: classifying the population in the social network rumor model, drawing a relationship flow chart of each population, constructing a differential equation expression of the rumor model, finding the rumor-free equilibrium point and rumor-containing equilibrium point of the model based on whether the rumor is popular, calculating the basic reproduction number, and further explaining the switching model. The present invention first proposes a hypothesis: assuming that there is a social network composed of N individuals, the individuals can be regarded as nodes in the network, and the relationships between individuals can be regarded as edges between network nodes. In the entire network, the switching model is further explained using a nonlinear coupling relationship, adding a Markov chain to the contact infection rate, and adding anti-rumor agents to the traditional model, which is more in line with practical situations.

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 present invention discloses a logarithmic terminal sliding mode control method, device and equipment for a non-linear system, which relates to the technical field of sliding mode control. Aiming at the control problem of a non-linear second-order system, the present invention combines a terminal sliding mode surface and a natural logarithmic function to propose a logarithmic terminal sliding mode surface. Based on the terminal sliding mode surface, the proposed logarithmic terminal sliding mode surface accelerates the convergence rate of the state of the non-linear second-order system when it is far from the equilibrium point. At the same time, considering that the non-linear second-order system often contains unknown matching non-linear disturbances, which will affect the stability and control accuracy of the system, a sliding mode disturbance observer is designed based on the proposed logarithmic terminal sliding mode surface, realizing the fast convergence of the disturbance estimation error, which is convenient for the subsequent design of the controller. Finally, a stable first-order logarithmic terminal sliding mode controller is designed based on the Lyapunov stability theory, realizing the global fast convergence of the state of the non-linear second-order system to the equilibrium point, and improving the convergence rate and control accuracy.

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.

The invention discloses an intelligent thermal power plant high-level water collection cooling tower pollution discharge monitoring method. The method comprises the steps of data acquisition, environment sensitivity mapping function definition, cooling tower pollution discharge monitoring model definition, cooling tower pollution discharge monitoring model establishment and thermal power plant high-level water collection cooling tower pollution discharge monitoring. The invention belongs to the field of pollution discharge monitoring, and particularly relates to an intelligent thermal power plant high-level water collection cooling tower pollution discharge monitoring method, which comprises the following steps: constructing environmental sensitivity mapping based on a difference absolute value, and amplifying tiny offset; the offset after mapping is amplified again through exponential nonlinear characteristics of sine and cosine, so that early warning is facilitated; on the basis of construction of a coupling nonlinear ordinary differential equation set, a balance point set is constructed for anomaly judgment, and missing report and false report are reduced; through multi-strategy local search and a radius attenuation mechanism, exploration and utilization are balanced; and based on a hybrid updating mechanism, diversification jumps out of local optimum, so that the pollution discharge monitoring efficiency under a complex environment working condition is improved.

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 present invention relates to a data-driven state feedback control method and device for a periodic piecewise linear circuit system. The method comprises: constructing a periodic piecewise linear closed-loop system model to obtain basic system information; performing input-output experiments on each subinterval to obtain input-output data that satisfies a response rank condition; describing the system dynamics of the linear system on the subinterval based on the input-output data with sufficient excitation, and obtaining the closed-loop characteristics of the system represented by the input-output data; constructing a Lyapunov function of the closed-loop periodic piecewise linear system, and using the Schur complement equivalence to construct the stability condition of the linear matrix inequality for the Lyapunov function; substituting the obtained input-output data into the stability condition to solve the controller gain matrix; and substituting the controller gain matrix back into the closed-loop system model to converge the state variables to an equilibrium point. The present invention adopts a data-driven approach to achieve effective control under unknown system parameters and achieve fast and flexible convergence.

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 invention discloses a dynamic adaptive calculation method for a power system, and belongs to the field of power systems, and the method carries out the adaptive calculation according to an analytical solution of an x-domain state variable of the power system, thereby judging and expanding a regular calculation step length according to a nonlinear intensity quantitative index. The calculation amount is reduced while the dynamic analysis precision is guaranteed, and the calculation efficiency is improved; the nonlinear characteristics of the dynamic unbalance point of the power system are considered, and the application range near the regular unbalance point can be clearly expanded, so that the calculation efficiency is improved while the precision is guaranteed; and realizing nonlinear analysis in the dynamic process of the system through a state variable analytic expression.

The present invention discloses an observation-based adaptive logarithmic terminal sliding mode control method and device, which relates to the technical field of sliding mode control. By nesting the terminal attractor into the natural logarithmic function, the present invention effectively combines the terminal sliding mode control and the logarithmic sliding mode control, realizes fast convergence both near and far from the equilibrium point, improves the global dynamics of the sliding surface, and constructs an adaptive logarithmic terminal sliding mode controller based on the super-twisting sliding mode control and the adaptive gain. The adaptive gain is updated according to the adaptive law, and the adaptive law is constructed based on a preset non-linear barrier function, realizing the intelligent adaptation of the super-twisting sliding mode control gain, so that the sliding mode variable is constrained within the preset boundary, and the interference estimation error converges rapidly based on the estimation of the interference by the observer. Under the constraint of the sliding mode variable, the global fast convergence of the state tracking error is realized, with high steady-state accuracy, the chattering phenomenon is weakened, and the convergence efficiency and control accuracy are improved.

The invention discloses a converter control method and device considering alternating current side phase angle feedback and a storage medium, and belongs to the field of novel power grid formation control. The method comprises the following steps: aiming at a direct current-alternating current power converter, considering the condition that the direct current-alternating current power converter is connected with an infinite bus or a dynamic center inertia (COI) power grid, establishing a converter model comprising explicit representation of energy dynamics, a direct current link, an LC output filter, a transmission line and the like, and determining a closed-loop kinetic equation under a hybrid angle control (HAC) strategy; based on the model and a control strategy, the existence, the stability and the boundaries of balance points of the closed-loop system are analyzed, and corresponding parameter conditions are given; considering the safety constraint of the power converter, designing current limit control compatible with hybrid angle control (HAC), and analyzing the stability of the current limit control; an implementation method of hybrid angle control (HAC) in practical application is researched and designed, the robustness and behaviors of the HAC under different working conditions are analyzed, and verification is carried out through a numerical example.

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 discloses a nonlinear power grid dynamic model order reduction method based on high-order polynomial mixed singular perturbation, relates to the field of smart power grids, and can reduce the order of a nonlinear power grid model so as to enable a model which cannot be processed by a stability algorithm due to too high order to be subjected to stability analysis. According to the method, firstly, multivariable high-order Taylor series expansion is carried out on each nonlinear part in a power grid differential equation set model at a balance point, so that a Taylor expansion is close to an original nonlinear expression as much as possible, and then a high-order derivative of a fast state variable in a system is made to be 0. According to the method, under the premise that important dynamic characteristics of the power grid are fully reserved, full order reduction is carried out on the model, and stability analysis of the high-order power grid becomes possible.

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 present invention discloses a method and system for simulating the electromechanical transient state of power system voltage stability. The method obtains data after the system is disturbed and uses a parameter identification algorithm to obtain the time constant for the load to recover to a steady state, as well as the proportional coefficients related to the static active load and reactive load. A conventional ZIP static load model is listed, and a dynamic ZIP load model is constructed using a proportional-integral-differential (PID) and a limiting step to reflect the input-output relationship between active and reactive loads and equivalent impedances. The system equilibrium point is determined based on the results of steady-state power flow calculations, and all dynamic equations of the entire network are linearized at the equilibrium point to obtain a state-space model. The eigenvalues ​​of the state matrix are calculated, and the voltage stability of the busbar where the load is located is determined based on the positive and negative signs of the real parts of the relevant eigenvalues. A dynamic time-domain simulation is performed on the adjusted system, and an N-1 or N-2 line fault is imposed on the entire network to simulate the voltage collapse scenario that may occur in the system. This provides theoretical support for proposing countermeasures after voltage instability.

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 invention discloses an electric power system stability optimization method and device based on multiple state variables, terminal equipment and a storage medium, and belongs to the field of electric power systems.The method comprises the steps that a quadratic Lyapunov equation is constructed and projected to a two-dimensional state space plane composed of any two different system state variables, obtaining stability domain boundary curve equations of different system working conditions; calculating a generalized participation factor according to the stability domain boundary curve equation and the initial equilibrium point before disturbance; screening related state variables according to the generalized participation factors; performing time integration on the quadratic Lyapunov equation to determine a system performance function, and solving partial derivative to obtain a generalized damping coefficient; optimizing related state variables according to the generalized damping coefficient; and adjusting system control parameters according to the optimized related state variables. By implementing the method and the device, a high-dimensional problem can be decomposed into a plurality of two-dimensional sub-problems, the analysis complexity is reduced, and the problem that in the prior art, the system complexity only aims at single parameter optimization is solved.