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198results about How to "Clear physical meaning" patented technology

Method for comprehensively evaluating electric energy quality

The invention discloses a method for comprehensively evaluating the electric energy quality by applying a TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) of a grey correlation coefficient matrix, which comprises the following steps of: taking electric energy quality data at all time intervals and standard data at all grades as an original decision matrix; determining subjective weights through an improved AHP (Analytic Hierarchy Process); determining objective weights through an entropy method; establishing a least square method decision model to obtain a comprehensive weight, so that the deviation of decision results under the subjective weights and the objective weights of all indexes is the least; carrying out standardization and weighted standardization on the decision matrix and obtaining the grey correction coefficient matrix by utilizing the grey theory; taking the grey correction coefficient matrix as a decision matrix of the TOPSIS to obtain the distance between positive ideal solutions and negative ideal solutions of all schemes and the relative closeness of the positive ideal solutions and the negative ideal solutions; and comparing the electric energy quality closeness at all the time intervals with the standard closeness at all the electric energy quality grades to finally obtain the electric energy quality grades at all the time intervals. With the adoption of the method, the electric energy quality evaluation result can be objectively and reasonably obtained under the situation of poor information, so that the practicability and the feasibility are stronger.
Owner:SOUTHEAST UNIV

Satellite Gravity Retrieval Method Based on 3D Interpolation Principle of Double Star Space

The invention relates to a method for precisely measuring an earth gravitational field, in particular to a satellite gravity inversion method based on a double-satellite spatial three-dimensional interpolation principle. An earth disturbing potential (obtained by computing an inter-satellite speed of a GRACE satellite K wave band measuring instrument, a satellite orbit position and a satellite orbit speed of a global positioning system (GPS) receiver, a satellite nonconservative force of an accelerometer and a satellite three-dimensional attitude data of a fixed star sensitive device) which is positioned on a gravity double-satellite orbit with a relatively irregular spatial position is interpolated three-dimensionally onto a reference spherical surface with a relatively regular spatial position and uniform grid division, so that the earth gravitational field is precisely and quickly inversed. By the method, satellite gravity inversion precision is high, physical meaning in the resolving process is clear, the computing speed is high, requirements on performance of a computer are low, and the method is sensitive to high-frequency signals in the gravitational field, so that the double-satellite spatial three-dimensional interpolation method is an effective method for resolving the earth gravitational field with high precision and high spatial resolution.
Owner:INST OF GEODESY & GEOPHYSICS CHINESE ACADEMY OF SCI

Automobile direction intelligent control method and control system based on driver model

The invention discloses an automobile direction intelligent control method based on a driver model. The method includes the steps of firstly, predicting a position where an automobile can reach after a moment T of a preview period according to the current running state of the automobile, comparing the position with a target position after the moment T, obtaining deviation of the two positions, obtaining the ratio of the deviation and T to serve as a predicted automobile transverse velocity, and then comparing the predicted automobile transverse velocity with an actual automobile transverse velocity to obtain a predicted automobile transverse velocity difference; secondly, obtaining a steering wheel turning angle through calculation, and controlling an automobile steering wheel according to the obtained steering wheel turning angle. The invention further discloses an automobile direction intelligent control system based on the drive model. The system comprises a preview module, a prediction module, a comparing module, a calculation module and a control module. Compared with the prior art, parameters of the driver model built in the method are directly obtained through parameters of the whole automobile, the driver module has the advantages of being simple in parameter and clear in physical meaning, and control of the automobile is more accurate and real.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Electric car charging station harmonic wave detection method in microgrid

The invention discloses an electric car charging station harmonic wave detection method in a microgrid in the electric engineering microgrid technical field. First, harmonic current in the microgrid are pretreated and is broken down into narrow band frequency signal families S1. Next, continuation treatment is carried out for the narrow band frequency signal families S1 through adoption of a self-adaption step-be-step continuation method to obtain frequency signal families S. Further, empirical mode decomposition is carried out for the frequency signal families S to obtain natural mode components. Hibert conversion is carried out for the natural mode components, and finally instantaneous frequency signals and instantaneous amplitude signals of the components are obtained. The electric car charging station harmonic wave detection method not only is suitable for analyzing nonlinear and nonstationary signals in power quality of the microgrid, but also can better reflect frequency characteristics and amplitude characteristics of the signals by analyzing linear and stationary signals in the power quality of the microgrid than other time-frequency analysis methods, and has more specific physical significance.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Method for positioning low-current grounding fault sections of power distribution networks on basis of transient energy analysis

The invention discloses a method for positioning low-current grounding fault sections of power distribution networks on the basis of transient energy analysis. The method includes steps of determiningpass frequency band ranges of digital filters and configuring a miniature PMU (power management unit) on each node of the power distribution networks; acquiring zero-sequence voltage phasors and zero-sequence current phasors of the various nodes of the power distribution networks by the aid of the miniature PMUs, judging whether faults of systems occur or not according to the zero-sequence voltage phasors and the zero-sequence current phasors of the various nodes, starting to position the faults if the faults occur, reading three-phase current signals recorded by the various miniature PMUs, computing transient zero-sequence currents of the various nodes by the aid of the three-phase current signals, processing the transient zero-sequence currents, computing transient energy of various sections, and determining the fault sections according to the transient energy of the various sections. The method has the advantages that physical meaning of fault features utilized by the method is clear, the method is high in positioning accuracy and reliability for the fault sections of various branch lines, and input of medium resistors connected with arc suppression coils in parallel or installation of signal injection equipment can be omitted.
Owner:SHANDONG UNIV +2

Photovoltaic power station equivalent modeling method

The invention relates to a photovoltaic power station equivalent modeling method. The photovoltaic power station equivalent modeling method comprises the steps of building a simulation model of a grid-connected photovoltaic generation unit, including, a transient control module; carrying out a fault simulation experiment for the grid-connected photovoltaic generation unit, obtaining active power response curves in the presence of different voltage drop depths and different time of duration, and storing the active power response curves in the presence of different voltage drop depths and different time of duration into corresponding offline databases; selecting matched offline databases based on the really measured voltage drop depth and time of duration, selecting the active power response curves from the matched offline databases based on the output of the grid-connected photovoltaic generation unit, and clustering and grouping the selected active power response curves based on the active power response similarity when the transient control module is enabled so as to obtain multiple generator set groups; calculating a first equivalent parameter of each generator set group and a second equivalent parameter of a current collection circuit, and building an equivalent model based on the first equivalent parameters and the second equivalent parameter.
Owner:HARBIN INST OF TECH +1

Method for calculating composite index of grid operation based on information source entropy

The invention provides a method for calculating composite index of grid operation based on information source entropy. According to the method, historical data of all indexes are subjected to statistics, the change law of the indexes is analyzed, the orderliness and the degree of stability of the historical data of the indexes are reflected by the information source entropy of the indexes, and then, the weight coefficients of the indexes are obtained. The method for calculating the composite index of the grid operation, provided by the invention, is different from the traditional index weight calculation methods which are based on subjective rating, each index entry serves as an independent information source, and the information source entropy of concerned indexes is calculated and serves as a weight calculation basis of the indexes, so that the fluctuation amplitude and the disorderliness of index values can be reflected objectively, and the contribution rate and the distinction degree of the indexes to the composite index of the grid operation are calculated scientifically. The method is simple in flow, small in calculation amount, low in developing difficulty and distinct in physical meaning and has strong practicability.
Owner:TSINGHUA UNIV

Design response spectrum based floor structure dynamic response testing method under walking loading

ActiveCN104101472AAccurate dynamic response analysisAccurate estimateVibration testingResponse spectrumEngineering
The invention relates to a design response spectrum based floor structure dynamic response testing method under walking loading. The design response spectrum based floor structure dynamic response testing method under the walking loading comprises (1) collecting a large amount of single-people walking load curves and forming into an actual measurement loading database; (2) inputting the actual measurement loading database to a standard excitation system after the actual measurement walking loading data is performed on normalization processing to be performed on time-procedure analysis and calculating to obtain an acceleration response spectrum of the actual measurement walking loading; (3) classifying with testers as objects, performing statics and fitting with an external envelope line of a tester response spectrum serving as a representative curve and constructing a complete piecewise function expression for the design response spectrum; (4) calculating dynamic response of every order vibration mode of the floor structure under the walking loading, combining the dynamic responses of the orders through a square and square root method and finally obtaining the floor dynamic response. Compared with the prior art, the design response spectrum based floor structure dynamic response testing method under the walking loading can accurately estimate the acceleration response of the floor structure under the walking loading.
Owner:TONGJI UNIV ARCHITECTURAL DESIGN INST GRP CO LTD

Intelligent ammeter provider multi-target integral evaluation method based on gray correlation degree

The invention discloses an intelligent ammeter provider multi-target integral evaluation method based on gray correlation degrees; the method comprises the following steps: suggesting an intelligent ammeter provider integral evaluation model so as to fully and objectively evaluate the intelligent ammeter provider; using a vector specification-based method to carry out dimensionless process for an index matrix, thus preventing inconsistent units and large magnitude order difference problems caused by different types of indexes; finally calculating the gray correlation degree, and converting the intelligent ammeter provider multi-target evaluation problem into correlation coefficient comparison. Compared with a conventional simple index weighting method, the intelligent ammeter provider multi-target integral evaluation method is more direct and scientific, can effectively solve the intelligent ammeter provider integral evaluation problem, can carry out multi-target integral quantification evaluation for a to-be-evaluated provider with obvious physics meanings, thus solving the problems that the multi-target evaluation is complex in indexes and strong in subjectivity; the intelligent ammeter provider multi-target integral evaluation method is high in evaluation accuracy, and scientific and objective in evaluations.
Owner:STATE GRID CORP OF CHINA +4

Hyper-spectral information extraction method based on main component and cluster analysis

The invention discloses a hyper-spectral information extraction method based on main component and cluster analysis. The method comprises the steps of: determining a standardized matrix Z of data of n samples; determining a correlation coefficient matrix R of the standardized matrix Z, calculating the characteristic roots of the correlation coefficient matrix R and characteristic vectors respectively corresponding to each characteristic root, and converting standardized sample data variables into main components, wherein a variable U1 highest in contribution rate is a number 1 main component, a variable U2 the second highest in contribution rate is a number 2 main component, ..., and a variable whose ranking is p is the number p main component; carrying out weighted summation on m main components which are highest in contribution rate to obtain an accumulated contribution rate, and taking the m main components whose accumulated contribution rate exceeds a threshold as cluster analysis main components; and carrying out classification scale calculation on the cluster analysis main components to determine the similarity of the samples, and classifying the samples according to the determined similarity of the samples. According to the invention, the main component analysis method and the cluster analysis method are combined to realize effective extraction of hyper-spectral image information.
Owner:BEIJING INST OF ENVIRONMENTAL FEATURES

Regional electric network failure diagnosis method based on five-layer and three-region cause and effect rule network

The invention discloses a regional electric network failure diagnosis method based on five-layer and three-region cause and effect rule network, which can perform backward reasoning for the protection and on-off action information in an SCADA (supervisory control and data acquisition) system for tracing back failure causes, so as to determine the failure element. And forwarding reasoning is performed for the failure causes to detect the protection of false operation and failed operation and on-off aggregation. The five-layer and three-region cause and effect rule network built in the invention has the characteristics of clear structure and explicit physical meaning and can perform graphical expression, so as to have strong intuitionism and to be convenient to easily understand. The judgment of the protection of false operation and failed operation and on-off is simple and fast by the operations of a plurality of aggregations. In the invention, various candidate reasons are mutually restrained by constructing an action condition layer; and the influences of various failure symptoms at the opposite side of a circuit to the side are reflected by constructing a middle diagnosis auxiliary area, so that the accuracy of failure diagnosis at the side is strengthened.
Owner:SOUTHWEST JIAOTONG UNIV

Subspace identification based forecasting method for superheated steam output of boiler of firepower power station

The invention discloses a subspace identification based forecasting method for superheated steam output of a boiler of a firepower power station, which comprises the following steps: firstly, acquiring production data from plant-level DCS (Distributed Control System) configuration software at regular time; secondly, correcting bad points, filtering and denoising; thirdly, calculating input and output variables required by model identification; fourthly, constructing an Hankel matrix by utilizing continuous acquired and processed data and rolling to update; fifthly, approximating the boiler process to a linear state space model; sixthly, using a subspace theory to identify a matrix of the state space model [A, B, C and D]; seventhly, utilizing the latest input energy information as the obtained input variables of the state space model after the identification and calculating output energy of future moments; eighthly, calculating the mean value at the same time by utilizing a historical forecast value and a current forecast result and correcting by utilizing the past forecast deviation; and ninthly, rolling to update the data of identification of the model. The forecasting method is applicable to online forecast of superheated steam output energy in the boiler production process and provides guidance and reference for the optimization control of boiler combustion.
Owner:ELECTRIC POWER SCI RES INST OF GUIZHOU POWER GRID CO LTD +1

Object-oriented programming method for reading and writing PSD-BPA data file

The invention relates to an object-oriented programming method for reading and writing a PSD-BPA data file. The method comprises the following specific steps: (1) analyzing the types and data formats of all cards in a BPA data file, and performing data abstraction; (2) defining a service primitive according to the result of data abstraction, designing a class structure framework; (3) completing the definitions of derived classes in the class structure framework in sequence from top to bottom; (4) implementing the class structure framework by adopting an object-oriented programming language; (5) determining the specific use way of the class structure framework according to an application requirement, and implementing and deploying an interface program; (6) verifying the correctness of the deployed interface program in different computation environments. Compared with the prior art, the object-oriented programming method has the advantages that the design of a BPA data interface ha a consistent hierarchical relation with a BPA program user manual, so that the extensibility, portability and maintainability of a data interface program are ensured, and the difficulty in developing and maintaining a BPA bilateral data conversion interface is lowered.
Owner:SHANGHAI JIAO TONG UNIV +1

Corrosion residual life prediction method of transmission line towers in coastal regions

ActiveCN105466843AControl and prevent dropped callsClear physical meaningWeather/light/corrosion resistanceEngineeringTower
The invention discloses a corrosion residual life prediction method of transmission line towers in coastal regions. The method comprises the following steps: 1) measuring average thickness of tower material's residual zinc coating of a predicted tower; 2) measuring the minimal residual thickness of tower material's severely corroded regions of the predicted tower, and subtracting the minimal residual thickness from tower material's original thickness of the predicted tower so as to obtain the tower material's maximum corrosion depth of the predicted tower; 3) determining iron corrosion rate and zinc corrosion rate of the coastal region where the predicted tower resides; 4) obtaining the tower material's maximum allowable corrosion depth of the coastal region where the predicted tower resides; and 5) calculating corrosion residual safe life of the predicted tower. According to the invention, residual safe life of corroded transmission line towers in coastal regions can be predicted rapidly and accurately. Thus, measures can be taken timely so as to control and prevent accidents such as off-line, power failure, trip-out, etc. of transmission lines due to corrosion. The method of the invention has advantages of high accuracy and strong practicality.
Owner:STATE GRID CORP OF CHINA +2

Communication signal classification and recognition method based on multi-feature association and Bayesian network

The invention discloses a communication signal classification and recognition method based on multi-feature association and a Bayesian network, and belongs to the technical field of communication signal processing. According to the method, based on characteristics of large fluctuation range of the signal-to-noise ratio and insufficient training samples, features of the time domain, the frequency domain and the space domain of signals are associated, a Bayesian network model is designed, a Bayesian network classifier is obtained through structure learning and parameter learning, and a user cognition result is obtained. According to the method, cognitive classification is performed by employing the Bayesian network classifier, the dependence relations between the features of dimensions can be fully mined, the physical meaning is clear, and the method is applicable to a small-sample condition and an incomplete data set; performing a discretization pre-processing method by employing combination of priori and clustering, and original data information can be reserved to the maximum; and parameter learning is performed on the Bayesian network model by employing random sampling so that good classification accuracy can still be obtained in the conditions of large fluctuation range of the signal-to-noise ratio and insufficient quantity of the training samples.
Owner:BEIHANG UNIV
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