39 results about "State space matrices" patented technology

The invention discloses a grid-connected resonance analysis method and system based on a photovoltaic virtual synchronous generator. An information module is used for establishing a photovoltaic virtual synchronous generator grid-connected small signal model; the analysis module analyzes the grid-connected resonance mechanism of the photovoltaic virtual synchronous generator by using a state spacestrategy in combination with the small signal model, and constructs a state space matrix; the calculation module is used for solving characteristic values and left and right characteristic vectors ofthe state space matrix, obtaining resonance participation factors of all nodes when grid-connected resonance of the photovoltaic virtual synchronous generator occurs, and respectively carrying out calculation processing; and the analysis module analyzes the influence of element parameters on resonance stability by using a Lyapunov analysis strategy and a resonance participation factor to obtain aresonance influence rule. According to the method, the influence of the grid-connected resonance mechanism, accurate parameters and elements of the photovoltaic virtual synchronous generator on the stability is analyzed through a state space strategy, and a theoretical basis is provided for parameter design and optimization of the photovoltaic virtual synchronous generator in actual engineering and evaluation of the photovoltaic grid-connected electric energy quality.

The invention belongs to the technical field of carrier rocket control, and particularly relates to a complex system transfer function computing method based on the high-precision polynomial arithmetic. The method comprises the first step of pre-processing input data, the second step of calculating a state space matrix, the third step of calculating the transfer function of a rocket body by adopting the FADEEVA method, the fourth step of expanding floating point data information to obtain the transfer function of the sum of the rocket body, a platform and a gyroscope and the transfer function of the sum of the rocket body, the platform, the gyroscope and a steering engine, and the fifth step of obtaining the transfer function of an attitude control system open loop. The limitation of the word length of a robot is broken through, effective figures are reserved, the computing round-off error is reduced, and the solving precision of the transfer function is improved in the process of processing a complex system.

The invention discloses a self-adaptive optimal AGC control method based on integral reinforcement learning. The method comprises the steps: 1), building a single-region power system frequency response model, and calculating a power system state space matrix; 2) establishing an evaluator-executor neural network based on a strategy iterative algorithm in reinforcement learning, wherein the evaluator-executor neural network comprises an evaluator network and an executor network; and 3) inputting the state space matrix of the power system into the evaluator-executor neural network, and performing resolving to obtain an optimal control strategy. According to the method, the optimal cost function is learned by using the integral reinforcement learning strategy, so that the learning process can be carried out under the condition that a system dynamic model is unknown, and the learning speed and accuracy are improved from the perspective of weakening a continuous excitation condition.

The invention relates to a method for estimating the risk of jellyfish injury, which includes: (1) storing the spatial position of the tourist with a state matrix hp, at the central position (i, j) of the tourist, hp (i, j)=1, and the rest The position is hp=0 (2) calculate the expected number of jellyfish in the research area; (3) use the state matrix fp to store the spatial position of the jellyfish, the grid (i,j) where the jellyfish appears, then fp(i,j)=1 ; The grid (i, j) where jellyfish does not appear, then fp(i, j) = 0; (4) Determine the local rules; (5) Determine the direction of the water flow and wind speed in the research area to point to the shore; (6) Determine the tourists The active area is the observation area H; (7) determine the update time; (8) determine the asynchronous update; (9) implement the algorithm in (1)-(8) based on MATLAB or Fortran, the frequency of jellyfish wounding is close to that of jellyfish (10) Give early warning instructions to bathing places according to early warning standards. The method of the invention can simulate the probability of jellyfish wounding, evaluate the risk of jellyfish wounding, and give bathing places early warning instructions according to early warning standards, thereby rationally managing bathing places and greatly reducing the probability of jellyfish wounding people.

The invention discloses a numerical-control machine tool feeding system modeling method based on an improved SVD (singular value decomposition)-Krylov algorithm. The method includes creating a state space equation model of a numerical-control machine tool feeding system according to a kinetic equation; acquiring an original system state space matrix, an original system and a transfer function model; setting the order of an order reduction system, and starting a multipoint moment matching SVD-Krylov algorithm for order reduction; outputting a state space matrix of the order reduction system, the order reduction system and a corresponding order reduction transfer function model; performing order reduction algorithm simulation verification according to a orthogonal experiment method and a time response method. Asymptotic stability of the model subjected to order reduction based on an order reducing and modeling algorithm can be guaranteed, and calculation efficiency is high; an iterative algorithm is adopted, moment matching quantity is multiplied, and order reduction accuracy is improved. The numerical-control machine tool feeding system modeling method has the advantages that order reduction accuracy and calculation efficiency are improved remarkably, and modeling and simulating speeds of the numerical-control machine tool feeding system are increased greatly.

The invention discloses a control parameter coordination method for an interconnection system of a wind driven generator and a synchronous generator, and the method comprises the following steps of S1, building a linearization state space model of each wind power plant and the synchronous generator in a to-be-researched power system through the linearization at a steady-state operation point; S2, calculating a closed-loop interconnection system state space matrix and the indexes, such as characteristic values and participation factors of the closed-loop interconnection system state space matrix, etc., through a power system network topology structure. In order to meet the requirement for the stable operation of the power system, a dynamic interaction phenomenon needs to be eliminated, and meanwhile, the system has a certain stability margin, so that certain external interference can be resisted.

The invention provides a weak and small target detection method under the sea clutter background based on the "multi-scale directed Lyapunov index". Hilbert transformation is performed on the radar echo data and the instantaneous phase angle theta is solved, first-order and second-order differential theta<.> and theta<..> are calculated and a state space matrix [theta, theta<.>, theta<..>] is constructed; and the state space is divided into sub-matrixes having no mutual intersection according to a certain scale, the covariance matrix of each sub-matrix is solved and eigenvalue decomposition isperformed, the main eigenvalue sigma<ip> and the eigenvector v<ip> are extracted, the inclined angle psi between the adjacent covariance matrix main eigenvectors is calculated, and (sigma<ip>, psi) is defined as the directed Lyapunov index of the radar echo data. The (sigma<ip>, psi) obtained according to different division length forms the multi-scale directed Lyapunov index, and the weak and small target under the sea clutter background can be accurately detected by the fluctuation characteristics of the index.

The invention discloses a bridge damage identification method based on non-iterative finite element model correction, and the method comprises the steps: employing the acceleration response of a bridge under the action of pulse excitation or environment excitation, and recognizing the inherent frequency, damping ratio and vibration mode of the bridge from the acceleration response through a random subspace algorithm; the identified modal parameters are utilized to reconstruct characteristic values and characteristic vectors of a state space matrix according to a preferred direction and sequence, and the characteristic values and the characteristic vectors serve as targets of modal parameter assignment in the non-iterative finite element model correction process; therefore, the state space matrix of the initial bridge finite element model is uniquely corrected, the updated bridge rigidity and damping matrix is calculated through the state space matrix, and then the damage position and degree of the bridge are identified by using the change of the units in the updated bridge rigidity matrix. The method can effectively solve the problem that most existing bridge damage recognition based on iterative finite element model correction is large in calculation workload, so that the damage recognition efficiency can be improved, and the calculation cost is reduced.

The invention is a method for calculating the natural torsional vibration frequency of a half-speed nuclear power unit. It includes the following steps: 1) Obtain the moment of inertia of the concentrated mass of the half-speed nuclear power unit and the stiffness coefficient between the mass blocks; 2) Establish the moment of inertia matrix and stiffness coefficient matrix of the above half-speed nuclear power unit; 3) Calculate the half-speed nuclear power unit The state space matrix of the rotation state equation of the unit; 4) Determine the eigenvalues ​​of the state space matrix through the eigenvalue calculation method. The present invention designs a new eigenvalue application algorithm, which is based on the moment of inertia matrix of the half-speed nuclear power unit and the stiffness coefficient matrix between the mass blocks of the unit, uses the rotation state equation, and uses parameter per unitization to unify the electrical System and mechanical system interface models. The invention is applicable to the calculation of the natural torsional vibration frequency of half-speed nuclear power units, has a high degree of integration with actual engineering, and can be applied to the subsynchronous oscillation analysis of such nuclear power units.

The invention provides a photovoltaic virtual synchronous generator control parameter tuning method and system. The method comprises steps: the minimum damping ratio ximin is acquired, and tuning ranges of an active droop coefficient KDp, virtual inertia J, virtual resistance Rv and virtual inductance Lv are acquired; the KDp and the J are set to be the maximum values, and the Rv is set to be theminimum value; a state space matrix An*n of a photovoltaic virtual synchronous generator grid-connected system is built, and according to the state space matrix An*n, a group of damping ratio expressions is obtained; a feasible domain U1 of the Lv is calculated; the feasible domain U1 of the Lv and the tuning range UL are subjected to intersection, if the intersection result is empty, the value ofthe J is reduced, the former step is returned to calculate the feasible domain U1 of the Lv again, and if the intersection result is not empty, the value of the virtual inductance Lv is set accordingto the intersection result; a feasible domain U2 of the Rv is calculated and obtained; and the feasible domain U2 of the Rv and the tuning range UR are subjected to intersection, and the value of thevirtual resistance Rv is set according to the intersection result. Thus, photovoltaic virtual synchronous generator control parameter tuning can be effectively and quickly realized.