25 results about "Distributed parameter model" patented technology

The invention discloses a flexible mechanical arm vibration control method based on T-S fuzzy modeling, and belongs to the technical field of intelligent manufacturing and distributed parameter system control. The flexible mechanical arm vibration control method comprises the steps that a flexible mechanical arm T-S fuzzy distributed parameter model considering nonlinear disturbance and time-varying and time-lag is constructed; designing a fuzzy boundary observer under a limited boundary measurement condition to realize state estimation; introducing a controller random failure modeling mechanism based on a Markov process, and designing a fault-tolerant boundary controller; dynamic boundary sampling is realized in combination with AETM, and the consumption of communication resources is reduced; and stability and performance criteria are constructed by using LKFs and LMI methods. According to the method, the robust stability and performance guarantee of vibration suppression of the flexible mechanical arm are realized under the conditions of limited measurement and failure of the random controller.

The invention discloses a pilot protection method and system based on new energy transmission line waveform similarity, and the method comprises the steps: obtaining a local-side voltage measurement value and a current measurement value of a power transmission line, and an opposite-side voltage measurement value and a current measurement value of the power transmission line in real time, and judging whether protection is started or not according to a current break variable condition; according to a pre-constructed distribution parameter model, calculating a current deduction value of the side by using the collected voltage measurement value and current measurement value of the opposite side of the line; substituting the current measurement value sequence of the side and the current deduction value sequence of the side in the sampling period into a Zensen. Shannon divergence formula to calculate the Zensen. Shannon divergence value of each phase; and calculating pilot protection action quantity and braking quantity based on the Zensen. Shannon divergence value, comparing the action quantity and the braking quantity of each phase, and performing corresponding protection action. A distributed parameter model is adopted, so that the adverse effect of capacitance current on protection is reduced; the problem that reliability and sensitivity are insufficient when pilot protection of a traditional power transmission line is applied to a new energy sending-out line is solved.

The invention discloses a cable outer sheath fault detection method considering signal attenuation, and the method comprises the steps: S1, building a detection model of a clinging type cable outer sheath, and enabling the detection model to take two parallel cable metal sheaths as signal transmission lines; s2, establishing a distributed parameter model, wherein the distributed parameter model comprises a series resistor, a series inductor, a parallel conductor and a parallel capacitor per unit length; s3, establishing a shunt capacitance calculation model and calculating total shunt capacitance; s4, building a signal attenuation amplitude calculation model, evaluating the attenuation degree of the detection signal, and judging the applicability of the detection signal according to the attenuation degree; and S5, on the premise of judging that the signal is applicable, injecting a traveling wave signal into the cable metal sheath, and positioning a damage point of the cable outer sheath based on the reflected signal. According to the method, the problems that the fault detection precision is low and the signal applicability cannot be evaluated in advance due to serious signal attenuation in the tightly laid cable tunnel are solved, and the detection accuracy and reliability are remarkably improved.

This invention relates to a single-end distributed parameter fault location method for ultra-high voltage (UHV) transmission lines, comprising: acquiring the line parameters of the UHV transmission line under test and determining whether a fault has occurred; acquiring the three-line voltage vector and three-phase current vector of the faulty end of the transmission line, establishing a distributed parameter model of the transmission line, and dividing the distributed parameter model of the transmission line into a fault-side segment model, a fault-opposite-side segment model, and a fault branch model according to the fault region; employing a single-end phasor domain centralized parameter fault location method to solve for the initial values ​​of the fault location and fault resistance; based on the fault-opposite-side segment model, constructing a fault location equation with the fault location and fault resistance as variables, and iteratively solving for the fault location and fault resistance as an optimization problem, as the fault location result. Compared with the prior art, this invention significantly improves the fault location accuracy of UHV long-distance transmission lines.

This invention discloses a method for calculating the steady-state voltage and circulating current of the sheath based on a distributed model of a multi-loop terrestrial cable. The method includes: 1. Obtaining the factors affecting the steady-state induced voltage and circulating current of the sheath of a multi-loop single-core terrestrial cable; 2. Establishing a distributed parameter model per unit length of the multi-loop single-core terrestrial cable, thereby obtaining the linear equation matrix describing the entire multi-loop terrestrial cable system; 3. Calculating the series impedance of the multi-loop single-core terrestrial cable lines in the system's linear equation matrix; 4. Calculating the parallel admittance between the multi-loop single-core terrestrial cable lines in the system's linear equation matrix; 5. Constructing the impedance matrix and admittance matrix to complete the system's linear equation matrix; 6. Determining the boundary conditions of the system's linear equation matrix; 7. Solving the system's linear equation matrix to obtain the values ​​of the steady-state induced voltage and circulating current; 8. Calculating the steady-state induced voltage and circulating current of the sheath of a multi-loop single-core terrestrial cable with the same arrangement. This invention eliminates repetitive modeling and simulation calculations, improves the model's adaptability, and has significant engineering value.

The application discloses a kind of electromagnetic transducer modeling and dynamic distributed parameter confirmation method considering electro-magnetic-mechanical-acoustic coupling, comprising: constructing electromagnetic transducer system dynamic multi-physical field distributed parameter model DPM;Based on parallel genetic algorithm PGA model optimization method;The dynamic multi-physical field distributed parameter model DPM includes: constructing excitation circuit equivalent model, the excitation circuit equivalent model includes several excitation main loop units, several air gap leakage magnetic loop units and several permanent magnet loop units;Construct mechanical structure equivalent model, the mechanical structure equivalent model includes system radiation plate face, spring system and rubber plate face and so on physical model.The PGA algorithm is optimized to DPM model parameter in the application, improves the performance efficiency of electromagnetic transducer, and provides a new method for the design of electromagnetic transducer.

The application discloses an energy integral differential protection method and system based on a distribution parameter model, which comprises the following steps: collecting three-phase voltage and three-phase current instantaneous values of a line at a local side and an opposite side in real time; calculating three-phase current calculation values of the local side at the same time based on the three-phase voltage and three-phase current instantaneous values of the opposite side; calculating three-phase current difference currents based on the three-phase current instantaneous values of the local side collected in real time and the three-phase current calculation values of the local side at the same time; calculating three-phase differential current operating quantities based on the three-phase current difference currents; and forming an energy integral differential protection operating criterion by using the three-phase differential current operating quantities, and performing differential protection when the three-phase differential current operating quantities meet the differential protection operating criterion. The application solves the problems of frequency deviation and harmonics of traditional Bergeron phasor differential protection after faults of power electronic devices such as new energy and flexible direct current, and improves the differential protection operating performance in a new energy power transmission scene.

The invention discloses a cable distribution parameter model construction and wave process analysis method, and relates to the technical field of the power industry, and the method comprises the steps: analyzing a cable structure to determine the hierarchy of the cable structure; constructing a distributed parameter model composed of unit length resistance, inductance, conductance and capacitance according to the ratio of the wavelength of the traveling wave to the length of the cable; an equation set is listed based on the Kirchhoff's law, and a transmission line partial differential equation describing the electromagnetic transmission characteristics of the cable is deduced; a refraction and reflection rule of traveling waves in a cable is analyzed, voltage and current refraction and reflection coefficients are deduced to determine traveling wave propagation behaviors, and in addition, time domain traveling wave fault distance measurement, fault distance measurement based on an improved head end reflection coefficient spectrum and insulation defect online monitoring based on active signal injection can be achieved in an extending mode. The method can eliminate the periodic distortion of the traditional frequency domain reflection spectrum, improves the fault distance measurement precision, achieves the real-time monitoring of the insulation state, and guarantees the safe and stable operation of the cable.

The invention relates to the technical field of power system fault detection, in particular to a photovoltaic power distribution network single-phase earth fault distance measurement method based on a cat swarm algorithm, and the method comprises the following steps: 1, building a distributed parameter model; step 2, constructing a fault model; step 3, setting a fitness function; according to the method, the cat swarm algorithm is combined with a distribution parameter distance measurement principle, and the accuracy and reliability of single-phase earth fault distance measurement of the photovoltaic power distribution network are improved by utilizing the advantages that the cat swarm algorithm is rapid in convergence and not prone to falling into a local optimal solution, so that the accuracy and reliability of fault distance measurement of the single-phase earth fault of the photovoltaic power distribution network are improved. Accurate results can be obtained in different fault conditions and environment changes, the method is not affected by distributed photovoltaic access, and the method has good universality.

The invention discloses a sand blockage intelligent real-time monitoring method based on dimensionless parameters, and belongs to the technical field of petroleum and natural gas development, and the method comprises the following steps: S1, building a data channel, and obtaining construction pressure, displacement, sand concentration and optical fiber data in real time on a fracturing construction site; s2, defining dimensionless construction parameters and calculating an NSD value; s3, constructing a sand plugging risk real-time prediction model based on a neural network; s4, analyzing and verifying the model effect based on the NSD change of the key time node; s5, making a sand blockage early warning risk grade and an early warning index; and S6, outputting a sand plugging risk monitoring result in real time and optimizing construction parameters. According to the sand blockage intelligent real-time monitoring method based on the dimensionless parameters, the dimensionless mortar distribution parameter model is constructed, and the real-time construction data and the neural network algorithm are combined, so that early warning can be provided before sand blockage occurs, fracturing construction design is optimized, and construction efficiency is improved.

The invention provides a method for positioning a broadband harmonic unstable source of a new energy station. The method comprises the following steps: S1, obtaining a topology and parameters of a new energy station system, and building an equivalent frequency domain impedance model of the new energy station system; s2, establishing a new energy station system frequency domain node admittance matrix according to the new energy station equivalent frequency domain impedance model; s3, approximating the determinant of the frequency domain node admittance matrix of the new energy station system into a polynomial through a Pade approximation method to solve a system intrinsic mode; and S4, according to the inherent mode of the system, positioning the harmonic unstable source of the system. The method considers that the line distribution parameter model is a necessary condition for accurately evaluating the harmonic instability phenomenon of the new energy station. Furthermore, on the basis of considering a line distribution parameter model, a region influenced by a harmonic instability phenomenon is researched, and a weak link of the system is positioned.

The present application relates to a distributed power rich area cable insulation partial aging online positioning method and system, the positioning method comprising: establishing a cable distributed parameter model; superimposing f 1±1kHz and f 2±1kHz near wideband signals, the system continuously collects outlet three-phase voltage and current during operation and obtains amplitude-frequency characteristics through Fourier analysis, and the amplitude-frequency characteristics are divided by the amplitude of each phase voltage and current at each frequency point to obtain the wideband impedance spectrum of each phase; the second series resonance frequency measured in the current operating state f 2 is substituted into the cable insulation partial aging distance formula to obtain the cable insulation partial aging distance. The positioning system comprises a first calculation module, a second calculation module and a positioning module; the first calculation module determines the mathematical model of the power station back-end cable and power grid system impedance; the second calculation module obtains the impedance formula of the mathematical model of the power station back-end cable and power grid system impedance after partial aging; and the positioning module determines the position of the partial aging defect of the measured cable. The present application can obtain accurate positioning of partial aging.

The invention discloses an energy integral differential protection method and system based on a distributed parameter model. The method comprises the following steps: acquiring three-phase voltage and three-phase current instantaneous values of a local side and an opposite side of a line in real time; calculating a three-phase current calculation value of the current side at the same moment based on the instantaneous values of the three-phase voltage and the three-phase current of the opposite side of the line; calculating to obtain a three-phase current difference current based on a local-side three-phase current instantaneous value acquired in real time and a local-side three-phase current calculation value at the same moment; calculating a three-phase difference current acting quantity based on the three-phase current difference current; and forming an energy integral differential protection action criterion by using the three-phase difference flow acting quantity, and performing differential protection action when the three-phase difference flow acting quantity meets the differential protection action criterion. The problems of frequency offset, harmonic waves and the like after the traditional Bergeron phasor differential protection suffers from faults of power electronic equipment such as new energy and flexible direct current are solved, and the differential protection action performance in a new energy power transmission scene is improved.

The invention discloses a small interference stability analysis method and system considering an electromagnetic transient state of a power system, and belongs to the technical field of power system stability analysis. The method comprises the following steps: performing steady-state load flow calculation by adopting a Newton-Raphson method, and establishing a distribution parameter line model; initializing a dynamic element based on the power flow result; linearizing the dynamic phasor model at the balance point to obtain a matrix bundle; and solving the generalized eigenvalue by adopting a partial eigenvalue calculation method, judging the modal stability, and analyzing the participation degree and energy distribution of the oscillation modal in combination with the eigenvector. The system comprises corresponding modules. The problems that balance point calculation is not convergent and a distribution parameter model is insufficient in small interference analysis in the electromagnetic transient state are solved, quantitative analysis, stability judgment and source positioning of broadband oscillation are achieved, and the method is suitable for a modern electric power system.

A system and method for an adaptive full focus method (TFM) includes obtaining full matrix capture (FMC) data of a region of interest of an article, the region of interest being made of a material; for each unit of a set of units in the article, evaluating the FMC data to obtain a parameter for relating to a material property of the material; associating the parameters of each cell in the set of cells with a state model of the material to determine an anisotropic state of each cell in the set of cells in the article; generating a distribution parameter model of the material anisotropy of the product by using the anisotropy state of each unit in the group of units in the product; and operating the beamformer with the distributed parameter model using the TFM to image the region of interest.

The invention discloses an IGBT service life prediction method based on an improved trust region reflection nonlinear least square method and a distributed parameter degradation model, and belongs to the technical field of IGBT device service life prediction methods. Parameters of the distributed parameter life model are estimated in combination with an improved TRRLS algorithm, accurate life prediction is realized while parameter dynamic drift characteristics under IGBT'electricity-heat-force 'multi-field coupling are considered, the influence of noise interference and invalid parameters on a prediction result is reduced, the depiction capability of the distributed parameter model on local degradation can be brought into play, and the reliability of life prediction is improved. And the accuracy and the reliability of IGBT service life prediction are improved.

The invention relates to a reinforcement learning control method for a flexible mechanical arm with asymmetric time-varying output constraints. The reinforcement learning neural network control problem of a flexible mechanical arm system with asymmetric time-varying output constraints is researched. On the basis of the Hamiltonian principle, a distributed parameter model of the system is established, an execution-judgment structure reinforcement learning controller is designed according to the model, and the system cost function and the model uncertainty are approached while the optimal performance of the system is guaranteed. A time-varying asymmetric obstacle Lyapunov function is utilized to construct output constraints of the system on angle errors and vibration, and trajectory tracking and vibration suppression of the flexible arm are achieved. And finally, verifying the effectiveness of the proposed scheme on MATLAB software through a numerical simulation experiment.

This invention provides a method and apparatus for analyzing the coupling characteristics of asteroid impactors based on SPH (Smooth Particle Hydrodynamics), belonging to the field of spacecraft dynamics modeling. The method includes: establishing a liquid sloshing model described by the SPH method; SPH represents smooth particle hydrodynamics; calculating the liquid sloshing forces and moments in a non-inertial frame based on the liquid sloshing model; establishing a distributed parameter model of the flexible spacecraft; integrating the liquid sloshing forces and moments in the non-inertial frame into the distributed parameter model of the flexible spacecraft to establish a dynamic model of the liquid-filled flexible spacecraft; and, based on the dynamic model of the liquid-filled flexible spacecraft, analyzing the coupling characteristics of the central rigid body attitude and position, flexible appendage vibration, and liquid fuel sloshing as system states. This invention provides a new approach and reference for modeling liquid-filled flexible spacecraft.

The invention belongs to the technical field of magnetic suspension voltage detection, and relates to a SiC power amplifier driving magnetic suspension bearing end overvoltage detection and suppression method. The method comprises the following steps: firstly, constructing a pi-type distributed parameter model based on a transmission line theory, and calculating resistance, inductance, capacitance and conductance per unit length by considering a high-frequency skin effect, a proximity effect and dielectric loss; secondly, deducing a load end voltage traveling wave superposition expression, revealing a mechanism that an incident wave and a reflected wave are superposed to form overvoltage, and determining influences of propagation delay and a reflection coefficient; then, in combination with three-level PWM modulation, establishing a residence time optimization model, and deriving an optimal residence time analytic expression; and finally, establishing a normalized sensitivity model, quantifying the influence degree of each parameter on the overvoltage, determining the parameter priority, quantifying the parameter coupling rule, and providing reliable modeling support for optimization of PWM parameters of the SiC power amplifier driven magnetic suspension bearing system and a load end overvoltage suppression scheme. The method is scientific in principle, accurate in parameter calculation and high in engineering practicability.

The application discloses a flexible mechanical arm vibration control method based on T-S fuzzy modeling, belongs to the technical field of intelligent manufacturing and distributed parameter system control, and comprises the following steps: a T-S fuzzy distributed parameter model of a flexible mechanical arm considering nonlinear disturbance and time-varying time delay is constructed; a fuzzy boundary observer is designed under the condition of limited boundary measurement, and state estimation is realized; a controller random failure modeling mechanism based on a Markov process is introduced, and a fault-tolerant boundary controller is designed; dynamic boundary sampling is realized in combination with AETM, and communication resource consumption is reduced; and LKFs and LMI methods are used to construct stability and performance criteria. The application realizes robust stability and performance guarantee of flexible mechanical arm vibration suppression under the condition of limited measurement and random controller failure.

The invention relates to a same-tower double-circuit alternating-current transmission line zero-sequence parameter estimation method based on internal faults. The method comprises the following steps: establishing different mathematical models according to line length differences, adopting a single-section pi lumped parameter model for medium-short distance transmission lines to approximate a distributed parameter model, and adopting a distributed parameter model for medium-long distance transmission lines, therefore, the electromagnetic characteristics during the single-phase earth fault can be accurately represented. Based on voltage and current measurement data at two ends of the line, establishing a parameter equation set in a fault state by combining a Kirchhoff's law, and performing linear approximate processing on a nonlinear equation by using Taylor series expansion; through algebraic operation and matrix solution, an explicit analytical expression of a zero-sequence parameter is deduced, and precise calculation without iteration is realized. According to the method, zero-sequence parameters such as zero-sequence self-impedance and mutual impedance are estimated based on the single-phase earth fault of the same-tower double-circuit line, and the method is suitable for online identification of the zero-sequence parameters of transmission lines with different lengths and has the characteristics of high calculation efficiency, clear physical significance and high engineering applicability.

This invention relates to a method and system for discriminating rotor grounding protection in gas turbine generator-transformer units based on multi-source information, belonging to the field of gas turbine generator-transformer unit protection. The method includes: synchronously acquiring and preprocessing raw data to output a synchronous data sequence; performing a two-end measurement consistency check based on the synchronous data sequence and outputting a consistency flag; constructing a distributed parameter model of the rotor winding to segment the rotor, obtaining estimated values ​​of the ground insulation resistance and distributed capacitance to ground for each segment, as well as the location of the maximum residual, through a two-end constraint propagation inversion algorithm; for each segment, performing dielectric response analysis and health index calculation to obtain the health index for each segment; extracting fault features based on the health index and performing fault mode identification, outputting the fault mode type and confidence level; and classifying the risk level based on the health index and fault mode type. This invention realizes a fully autonomous and controllable multi-source information fusion diagnostic architecture.

The invention provides an FBG acceleration sensor research and development method based on an infinite degree-of-freedom system vibration theory (a distributed parameter model), and belongs to the technical field of structural intelligent health monitoring and vibration measurement. The core of the method is that an acceleration sensing structure is regarded as a continuous medium elastomer, based on an infinite freedom degree system vibration theory, mass distribution and fluctuation characteristics of the elastomer are considered, a distribution parameter model is established, a fluctuation equation of the distribution parameter model is solved, and the inherent frequency, the modal shape and the dynamic response of the system are accurately analyzed through a modal superposition method. Further, the sensitivity characteristic of the sensor is deduced, the coupling rule of the sensitivity and the frequency response under the multi-order modal coupling effect is disclosed, and the method is used for guiding accurate design and performance optimization of the sensor. According to the acceleration sensor research and development method provided by the invention, the influence of the design parameters of each module of the sensor on the resonant frequency and sensitivity can be accurately quantified, the directional optimization (such as high and low frequency high-sensitivity design) of the sensor performance is guided, and the durability is improved.

This invention belongs to the field of cable fault identification technology and discloses a method for fault identification and segment location of submarine cables based on multi-modulus collaborative analysis. First, it obtains the measured values ​​of voltage and current at the beginning and end of a three-core armored submarine cable, along with line parameters. Second, it establishes and decouples a distributed parameter model of the three-core armored submarine cable based on the line parameters. Utilizing the difference between measured and calculated values, and combining the decoupled modulus, it identifies faults in both cracking and short-circuit scenarios. Finally, it calculates the voltage at the cable segment joint location using the modulus to locate the short-circuit fault segment. This invention is applicable to fault identification and segment location of high-voltage, long-distance, segmented AC submarine cables. It offers high calculation accuracy and speed, is unaffected by the power supply at both ends, fault type, and transition resistance, facilitates measurement value acquisition, and has low implementation cost, making it highly significant in engineering practice.

The invention discloses a non-disassembly lead winding frequency response distribution parameter modeling method for a converter transformer. The method comprises the following steps: establishing a circuit model of a winding; calculating electrical data before winding deformation according to actual parameters of each element of the converter transformer; setting simulation deformation and element parameter variation, and calculating electrical data after winding deformation; and performing simulation analysis to obtain a frequency response curve. The electrical parameters before and after winding deformation are calculated more accurately through vectors, a frequency response curve is obtained by using a winding distribution parameter model, and the accuracy of non-lead-disassembly detection of the converter transformer can be improved by combining the changes of inductance parameters and capacitance parameters, the detection efficiency of the converter transformer is improved, and safe and stable operation of a power grid is guaranteed.