16 results about "Distributed parameter model" patented technology

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.

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 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 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 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.

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.

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.