15 results about "Characteristic polynomial" patented technology

The invention discloses a multi-unit multi-mode cogeneration power station load distribution method based on an improved Harlisia eagle optimization algorithm, and belongs to the technical field of energy management and optimization. The method comprises the specific steps that an HPHHO model is established, and characteristic equations of units in different heat supply modes (single extraction, absorption heat pump and cylinder switching) are analyzed; fitting an energy consumption characteristic polynomial of each unit through variable working condition calculation; taking the minimum total coal consumption as an objective function, and constructing an electric heating load balance constraint and a unit operation domain non-balance constraint; and optimizing multi-unit load distribution by using HPHHO. The method is compatible with the thermoelectric coupling relation of a multi-mode unit, the optimization problem under complex constraints is effectively solved, and it is ensured that a load distribution result meets external requirements and is in a feasible operation domain. Experiments show that compared with traditional HHO, the improved algorithm has higher convergence speed and stability, the total coal consumption of the system is remarkably reduced, and the economical efficiency and the operation efficiency of the combined heat and power generation power station are improved.

The invention relates to a plug-in type second-order feed-forward dual-mode repetitive control method. The method comprises the following steps: establishing a single-phase LCL type grid-connected inversion model based on a PP-SFDMRC controller; according to the single-phase LCL type grid-connected inversion model, a transfer function of a controlled object is obtained, a PP-SFDMRC controller structure is discretized, and a discrete transfer function of an internal model of the SFDMRC is obtained; the method comprises the following steps: acquiring an error transfer function of a PP-SFDMRC controller based on an SFDMRC internal model discrete transfer function by taking SFDMRC internal model stability as a target, converting the error transfer function into a characteristic polynomial, and determining a stability condition of the PP-SFDMRC controller; through stable conditions, corresponding parameters of the PP-SFDMRC controller are set, and odd and even harmonics are controlled to different degrees. The PP-SFDMRC strategy provided by the invention has excellent dynamic performance and super-strong adaptability to power grid frequency change.

The invention relates to the technical field of new energy grid-connected stability control, in particular to a small-signal steady-state discrimination method and system for a double-fed wind power plant controlled by a virtual synchronous machine and a medium, and the method comprises the steps: building a linear state space model for a double-fed fan controlled by a single virtual synchronous machine; listing a characteristic polynomial, and deducing a single-machine stability criterion inequality by using a Routh criterion; the method comprises the following steps: constructing a full-order state space matrix for a doubly-fed wind power plant comprising M units; decomposing the matrix into M independent subsystems, and performing eigenvalue decomposition on the current collection network impedance matrix to obtain a maximum eigenvalue; the M independent subsystems are equivalent to M-1 isolated subsystems without network interaction and an equivalent single-machine subsystem; and carrying out Routh criterion derivation on the equivalent single machine subsystem to obtain an explicit stability criterion inequality of the double-fed wind power plant grid-connected system and carrying out steady state discrimination. According to the invention, the problem that the stability boundary cannot be explicitly displayed under the complex power grid topology in the prior art is effectively solved.

The application provides a bridge crane control method based on adaptive integral IDA-PBC, and belongs to the technical field of crane control. The application comprises the following steps: a dynamic model of the bridge crane is established, an inertia matrix and a potential energy function are determined; the dynamic model is converted into an open-loop port controlled Hamilton form, the general form of an energy shaping controller and a damping injection controller is determined; the specific form of the expected potential energy function, the energy shaping controller and the damping injection controller is obtained; the adaptive integral controller is obtained by matching the open-loop port controlled Hamilton form and the state of the extended closed-loop Hamilton form; the adaptive law of unknown parameters is obtained by using the system stability condition; the system matrix and the actual characteristic polynomial are obtained by using the state equation of the closed-loop system, the expected characteristic polynomial is established by configuring to the ideal pole, and the control parameters are solved. The application can not only improve the trolley positioning accuracy and effectively reduce the load swing, but also can estimate the unknown parameters in the system in real time.

The application belongs to the technical field of cable diagnosis, and discloses a cable positioning defect quantitative evaluation method based on an extended Prony, which comprises the following steps: obtaining the head-end reflection coefficient of a cable to be measured; calculating a sample function and constructing an extended order matrix; calculating the effective rank of the extended order matrix and determining the least square estimation value of the first coefficient in the Prony method parameterization model; solving the characteristic polynomial of the Prony method parameterization model, obtaining the characteristic root of the characteristic polynomial, and calculating the approximate data; calculating the second coefficient by using the least square method according to the characteristic root of the characteristic polynomial and the approximate data; calculating and determining the defect position and the reflection coefficient amplitude of the corresponding reflection wave according to the characteristic root of the characteristic polynomial and the second coefficient; and quantitatively evaluating the defect severity based on the reflection coefficient amplitude at the defect position. The application can realize quantitative evaluation of the defect severity, thereby improving the effectiveness and accuracy of quantitative evaluation of cable defects with different severities.

The present invention relates to a method, apparatus, device, and storage medium for generating a random sequence. The method comprises: obtaining a characteristic polynomial; constructing a sparse matrix based on the characteristic polynomial; generating a state matrix shifted t times based on the sparse matrix; and obtaining a seed and combining it with the state matrix to generate a random sequence. The present invention optimizes the critical path in hardware, increases bandwidth, and reduces chip area by preprocessing the state matrix used to generate the random sequence.

The application provides a wideband measurement method and device based on a Prony algorithm, the method comprising: collecting time window data of a target power signal and constructing a sampling sequence; constructing a Hankel matrix based on the sampling sequence, separating the Hankel matrix into a low-frequency part and a high-frequency part through frequency analysis on frequency components; performing resampling processing on the low-frequency part of the Hankel matrix; for the resampling-processed low-frequency part, constructing a characteristic polynomial by using the Prony algorithm, and obtaining an initial frequency of each frequency component by solving the characteristic polynomial. The application solves the problem that current wideband measurement algorithms cannot accurately reflect the dynamic change characteristics of signals in a short time window and cannot accurately measure.

This invention discloses a method, system, and device for identifying subsynchronous oscillation modes under environmental excitation, belonging to the field of power system oscillation detection. Kalman filtering (KF) is used to estimate the coefficients of an autoregressive (AR) model to fit measured environmental data. The damping factor and frequency of the subsynchronous oscillation (SSO) mode can be directly obtained by solving for the roots of the characteristic polynomial corresponding to the AR model. Furthermore, multi-model segmentation filtering (MMPF) is applied to KF to select the correct AR model order. This invention combines the KF algorithm with MMPF, enabling the algorithm to directly identify weak SSO mode parameters from environmental data. The method has simple operation steps and short response time, thus possessing good application prospects.

The invention provides a precise positioning platform zero-error model prediction control method based on a characteristic polynomial, and belongs to the field of precise positioning platform ultra-precise tracking control, and the method comprises the following steps: S1, recognizing an autoregression model with external input according to the input and output data of a precise positioning platform; s2, establishing an augmentation system containing a tracking error according to the characteristic polynomial of the reference trajectory; s3, designing an optimization problem with constraints based on the augmented system containing the tracking error; and S4, solving an optimization problem according to a coordinate descent method to obtain a model prediction controller, and realizing zero-error tracking of the multiple-input multiple-output system. In order to solve the problem that a precision positioning platform is low in tracking precision when tracking an unstable reference trajectory or control input is limited, reference trajectory signals with characteristic polynomials can be tracked in a zero-error mode when constraint conditions are met, and the solving efficiency of a constraint optimization problem is guaranteed through application of a coordinate descent method. And the provided model prediction controller can be applied to high-frequency sampling hardware.

This invention discloses a method and system for identifying hydrological anomalies in water conservancy projects, belonging to the field of data processing technology. The invention collects hydrological observation data and maps monitoring sections as graph nodes, calculates the cross-sectional specific energy to construct transient graph signal vectors and unsigned topological Laplace matrices; calculates the global scheduling ground-state signal vector based on matrix polynomial expansion and performs differential operations to remove interference from compliant high-flow scheduling, obtaining local disturbance residual signal vectors; calculates the evolution rate by extracting algebraic invariants of characteristic polynomials, dynamically generating filtering boundaries; uses Chebyshev polynomial approximation to construct a bandpass graph filter to filter the residual signals, retaining structural anomaly signal vectors representing local structural damage; calculates the transient energy sequence vector and compares it with the energy alarm threshold to accurately identify abnormal physical nodes and generate alarm information. This invention eliminates compliant scheduling interference and achieves high-precision perception and positioning of physical structural disasters.

The application discloses a signal delay estimation method based on block processing, comprising the following steps: acquiring CSI data and preprocessing (validity test, noise filtering, selecting valid index); obtaining overlapping data blocks by block processing according to a preset block quantity and overlapping ratio; building Hankel matrix and enhancement matrix for each block, and obtaining delay estimation value through singular value decomposition, subspace separation and characteristic polynomial solving; assigning weight to each estimation value in combination with signal quality evaluation; and determining the final result based on the delay estimation value and weight information. In the application, a large matrix is disassembled through block overlapping, the singular value decomposition complexity and storage occupation are reduced, and lightweight hardware is adapted; the processing time consumption is shortened, the real-time demand in multiple scenes is met, the application can be run on ordinary equipment, and positioning deviation caused by delay is avoided.

The invention discloses a micro-grid secondary frequency modulation controller parameter optimization method and a related device, and belongs to the technical field of micro-grid stability analysis and control, and the method comprises the steps: firstly obtaining a model and parameters of a micro-grid, and building a time-delay differential algebraic equation which comprises primary and secondary frequency modulation and considers the communication delay influence; secondly, processing a time delay term by adopting Pade approximation to form a discretization matrix, and carrying out simultaneous operation on the discretization matrix and a time delay differential algebra to obtain a discretization model; next, all characteristic values of the discretization model are calculated through a QR method, and the rightmost characteristic value of the discretization model is used for approximately replacing the rightmost characteristic value of the time-delay differential algebraic equation; and then forming a discrete model characteristic polynomial, and calculating a time lag margin by using a Routh criterion. And finally, under the condition of considering the balance between the damping performance and the time lag margin of the system, establishing an objective function and a constraint condition of controller parameter optimization, and obtaining optimized controller parameters by adopting a genetic algorithm. The method can ensure that the system has good robust stability for time delay while meeting the corresponding damping performance.

The application belongs to the technical field of magnetic field measurement, and particularly relates to a magnetic target positioning method based on a magnetic gradient full tensor, which comprises the following steps: step 1, measuring the magnetic gradient full tensor at two observation points; step 2, solving the characteristic polynomial of the magnetic gradient tensor matrix at the two observation points, and calculating the corresponding real characteristic value and the corresponding unit eigenvector; step 3, calculating the normalized magnetic source intensity corresponding to the two observation points, the cosine of the angle between the relative position vector and the magnetic moment vector, and the cosine of the angle between the plane P1 and the plane P2; step 4, calculating the cosine value of the angle between the relative position vectors at the two observation points, and the modulus value of the relative position vector; step 5, establishing an equation group, and solving the unit direction vector of the relative position vector; and step 6, determining the magnetic source position. The application is convenient to measure, simple to calculate, and high in accuracy.

The present specification relates to the technical field of wellbore trajectory design, and provides a double-arc three-dimensional wellbore trajectory design method and device. The method comprises: obtaining a double-arc three-dimensional wellbore trajectory design model and corresponding constraint conditions; determining associated parameters corresponding to a target azimuth angle according to the constraint conditions; performing mapping transformation on the constraint conditions and the associated parameters by using a preset mapping transformation formula to obtain a target characteristic polynomial; calculating all real roots of the target characteristic polynomial; when the number of the real roots is greater than a preset threshold, analyzing the effectiveness of each real root based on the constraint conditions to obtain a design result of the target azimuth angle and a corresponding double-arc three-dimensional wellbore trajectory. Through the embodiment of the present specification, the stability of double-arc three-dimensional wellbore trajectory design can be improved.

The invention discloses a method for calculating the inherent frequency of a rotating motor under an operation condition, discloses a method for acquiring the inherent frequency of the rotating motor under the operation condition, and belongs to the technical field of online recognition of modal parameters of a motor structure. The method comprises the following steps: uniformly distributing N more than or equal to 4 unidirectional vibration sensors on a stator tooth part; the motor operates with load and synchronously collects vibration signals; carrying out zero-phase band-pass filtering on the signal; calculating a cross-correlation function of the reference point and the response point, and carrying out complex modal modeling to form a complex index series; constructing a matrix equation through unilateral cross-power spectrum transformation and multi-start time sampling, and obtaining a coefficient vector through SVD solution; and constructing a characteristic polynomial by a coefficient to obtain root, mapping to obtain continuous poles of the system, and outputting the inherent frequency and the damping ratio at the same time. The whole process does not need to be stopped, external excitation is not needed, the noise immunity is high, the frequency recognition error is smaller than 1%, and modal data under the real boundary condition is provided for motor NVH optimization and structure modification.