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184 results about "Piecewise linearization" patented technology
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Multiple no-manned plane three-dimensional formation reconfiguration method based on particle swarm optimization and genetic algorithm
InactiveCN101286071ASolving the Optimal Time Control ProblemSolving optimization problems with centralized controlGenetic modelsPosition/course control in three dimensionsLinear controlPiecewise linearization
The invention discloses a three-dimensional formation reconfiguration method for multiple unmanned aerial vehicles based on particle swarm optimization and genetic algorithm. The method considers the position of the unmanned aerial vehicle in the ground coordinates and the speed, track angle and course angle of the unmanned aerial vehicle when establishing a formation model, carries out subsection linear disposal of the control input of each flying unit in the unmanned aerial vehicle, replaces the approximate subsection linear control input with the continuous control input, then carries out global search by the genetic algorithm, subsequently carries out partial searching by the particle swarm optimization algorithm, on the base thereof, the particle swarm optimization is used to guide the genetic algorithm to search a global optimum solution so as to figure out the subsection linear control input. Compared with the traditional method, the method provided by the invention has good real-time performance and rapidity and can be used for solving the formation reconfiguration problem of multiple space robots under complex and dynamic environment.
Owner:BEIHANG UNIV
Modeling and system planning method for gas power grid combined multi-region comprehensive energy system
The invention particularly relates to a modeling and system planning method for a gas power grid combined multi-region comprehensive energy system. The method comprises the following steps: S1, establishing a coupling model of a power grid, a gas net, and a power grid-gas net and a multi-region comprehensive energy system model combined with constrained gas net-power grid; S2, establishing a planning model for optimal economic operation of a gas net-power grid combined multi-region comprehensive energy system, aiming at minimizing the total system operation cost; S3, converting the mixed integer nonlinear programming model in the model into a mixed integer second-order cone programming model by using a second-order cone programming method; performing nonlinear quantity linearization processing in the incremental piecewise linearization method model; and therefore, a large-scale mixed integer second-order cone programming model is established by taking the minimum total system operationcost as a target; and S4, a commercial planning problem solver is adopted to solve the large-scale mixed integer second-order cone programming model, and the optimal output and the total system operation cost of each unit in the multi-region comprehensive energy system are obtained.
Owner:NANJING INST OF TECH
Engine performance model
InactiveUS20090012762A1Improve accuracyAnalogue computers for vehiclesSimulator controlLinear enginePiecewise linearization
A method of constructing a piecewise linear engine performance model, comprises the steps of:(a) providing a non-linear engine performance model which iteratively calculates engine performance variables y from a plurality of sub-models, each sub-model representing the performance of a component of the engine;(b) defining a plurality of engine power conditions, each engine power condition being defined by one or more engine state variables x;(c) for each of the engine power conditions, using the non-linear engine performance model to determine partial derivatives δy of the engine performance variables y with respect to engine control variables u and with respect to the engine state variables x, the values of the partial derivatives δy being determined so that, on integrating the partial derivatives δy, the error between steady state values for the engine performance variables y calculated by the non-linear engine performance model and steady state values for the engine performance variables y calculated from the integrated partial derivatives δy is reduced or eliminated; and(d) constructing a piecewise linearised engine performance model in which calculation of the engine performance variables y involves combining each of the engine control variables u and the engine state variables x with the respective partial derivative δy.
Owner:ROLLS ROYCE PLC
A comprehensive energy system day-ahead economic dispatching method
ActiveCN109670730ASolve technical problems with inefficient utilizationGood effectResourcesEnergy system optimizationEnergy coupling
The present invention relates to a comprehensive energy system day-ahead economic dispatching method, by which the technical problem that the comprehensive energy utilization efficiency is low due tothe fact that an existing analysis method takes insufficient consideration of the multi-energy coupling effect of heat, electricity and gas can be solved. The method comprises the following steps of S100, establishing an energy efficiency model with economic benefit maximization as a target to meet the requirements of different users for electricity and heat under supply and demand balance and operation constraint conditions; S200, establishing a model objective function, taking the total profit maximization as an objective function, i.e., the total system cost is subtracted from the energy selling profit, wherein the total cost comprises the operation cost of power supply, heat supply and gas supply, the starting cost and the shutdown cost; S300, establishing a model constraint condition,wherein the model needs to meet two types of constraints of the system operation constraint and the operation constraint of each device; and S400, performing linear conversion on the model. Accordingto the method, the segmented linearization is adopted to carry out conversion solution, a good effect is achieved, and important guidance can be provided for researching comprehensive energy system optimization scheduling adapting to the marketization environment.
Owner:HEFEI POWER SUPPLY COMPANY OF STATE GRID ANHUI ELECTRIC POWER
Multi-model dynamic matrix feeding amount control method for coagulation system in waterworks
InactiveCN101020128AApplicable to coagulation dosing controlSmall amount of calculationSedimentation separationWater/sewage treatment by flocculation/precipitationModel dynamicsDynamic models
The multi-model dynamic matrix feeding amount control method for coagulation system in waterworks features that dynamic matrix predicting controller is constituted based on comprehensive multi-model dynamic matrix control theory and by means of using raw water flow rate as the control target, separating the whole system into several subspaces and separate experiments to obtain sectional linear models of the subspaces; and that outflow water turbidity is controlled through determining the dynamic model of the system, predicting the outflow water turbidity, weighting treatment to obtain overall control increment and regulating the feeding amount based on the current work conditions, practical water flow rate and certain weighting police. The present invention can ensure smooth outflow water turbidity, system running economic performance, high robustness and low cost.
Owner:SOUTHEAST UNIV +1
Sinus heart rate turbulence trend detection method based on piecewise linearization
InactiveCN103006210AReduce false positivesEasy to implementDiagnostic recording/measuringSensorsEcg signalVentricular contraction
The invention discloses a sinus heart rate turbulence trend detection method based on piecewise linearization. The piecewise linearization is adopted for specifically analyzing whether the variation trend of sinus heart rate accelerates first and then decelerates after premature ventricular contractions or not. The method includes the steps: (1) electrocardiosignal preprocessing; (2) self-learning process for first 10 seconds; (3) HRT (heart rate turbulence) sample collection; (4) piecewise trend analysis; and (5) turbulence trend representation based on a cloud model. The variation trend of the sinus heart rate at the RR interval is detected by means of piecewise linearization, and the turbulence trend is further represented by natural language through the cloud model. By the aid of an MATLAB (matrix laboratory) simulation tool, signals in an MIT-BIH heart beat irregularity database are selected for verification, and the variation trend of the sinus heart rate after single-time ventricular premature beat can be detected correctly. In addition, using the exponential smoothing method to predicate QRS complex occurrence positions to facilitate detection of QRS complex, and using a template for judging sinus heart beat is simple to implement and suitable for real-time treatment.
Owner:SHANDONG NORMAL UNIV
Real-time yield predicting method for catalytic cracking device
ActiveCN104789256ACalculation speedRealize real-time prediction of yieldCatalytic crackingNetwork modelCracking reaction
The invention discloses a real-time yield predicting method for a catalytic cracking device. According to the real-time yield predicting method for the catalytic cracking device, kinetic parameters and device parameters of a catalytic cracking reaction are corrected in real time by processing field real-time data by adopting a data reconciliation technology, and combining an improved differential evolution algorithm, so that the actual operating situations of the device can be described accurately by using a catalytic cracking device mechanism model. The method comprises the following steps: on the basis of a corrected model, analyzing the influence on the yield of a catalytic cracking product caused by key operation / process conditions, such as an operating temperature, a feeding load, a raw material preheating temperature, a reaction pressure, a residue adding ratio, a regenerator temperature, a catalyst-to-oil ratio and the like; performing piecewise linearization according to an influence trend, solving a linear equation to obtain corresponding Delta-Base yield data, associating the operating conditions and the Delta-Base yield data by combining a neural network modeling technology, and establishing a yield agent model, so that the yield data calculating speed is improved; the real-time yield predicting of a continuous catalytic cracking device is realized; a theoretical support is provided for establishing an accurate plan optimization PIMS model.
Owner:EAST CHINA UNIV OF SCI & TECH
Global time optimal trajectory programing method of industrial robot dynamic speed regulation
ActiveCN109434841AHigh running precisionImprove operational efficiencyProgramme-controlled manipulatorPiecewise linearizationJoint spaces
The invention provides a global time optimal trajectory programming method of industrial robot dynamic speed regulation. The global time optimal trajectory programming method comprises the steps thattrajectory points which may overrun are detected in advance by a searching mechanism based on iterative backwards of a fixed searching range, the trajectory points are divided into three classes according to the overrun conditions, corresponding algorithms are provided by a nonlinear problem segmentation linear idea, and particularly when a joint deceleration overruns, pushback and nudge of the trajectory points and a peak cut algorithm are combined to perform speed regulation. Algorithm dynamic speed regulation enables the overrunning trajectory points to meet constraint requirements, starting points of the searching range are continually issued to perform, and synchronous operation of searching detection, dynamic speed regulation and trajectory execution is ensured. By performing smoothing and limiting regulation on the velocity of movement and acceleration of a robot cartesian space and joint space synchronously, an original trajectory is guaranteed to move at a reasonable speed andin a constraint condition range; and time optimal of dynamic speed regulation is realized, smooth and efficient motion of the robot in a whole space is ensured, and the precision and operating efficiency of the robot are improved.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Real-time yield prediction method for hydrocracking device
ActiveCN104804761AAchieving real-time predictionReal-time acquisitionBiological neural network modelsHydrocarbon oil crackingReaction temperatureOperant conditioning
The invention discloses a real-time yield prediction method for a hydrocracking device. Field real-time data are processed with a data reconciliation technology, and hydrocracking reaction kinetics parameters are corrected in real time in combination with an improved differential evolution algorithm, so that a mechanism model can accurately describe the actual running condition of the device. On the basis of the corrected model, effects caused by key operation / process conditions such as the raw material density, the sulfur content, the nitrogen content, the reaction temperature, the pressure, the hydrogen-to-oil volume ratio and the like on hydrocracked products are analyzed. Piecewise linearization is performed according to the effect trend, a linear equation is solved, corresponding Delta-Base yield data are acquired, the operation condition is associated with the Delta-Base data with a neutral network modeling technology, a yield surrogate model is established, the yield data calculation speed is increased, real-time prediction of the yield of products of the hydrocracking device is realized, and theoretical support is provided for establishing an accurate plan optimization PIMS (process industry modeling system) model.
Owner:EAST CHINA UNIV OF SCI & TECH
Energy-management-based micro-grid system dispatching method in grid connection state
ActiveCN105207259AImprove applicabilityThe economic dispatch model is perfectEnergy industrySingle network parallel feeding arrangementsEngineeringMicro grid
The invention relates to an energy-management-based micro-grid system dispatching method in a grid connection state. The micro-grid system grid-connection running cost aims to be made minimum, a corresponding dispatching parameter is obtained by minimizing the running cost of a grid connection running target function, and therefore the electricity demands of all electric equipment in a micro-grid system are met. The built target function involves various cost influence factors such as equipment depreciation expense, fuel expense, maintenance expense, start and stop expense, environmental-protection expense, the equipment running cost and the power purchasing and selling cost, a piecewise linearization processing method is applied to covert a nonlinear problem into a linear problem, decision variables 0,1 are introduced to covert secondary constraint into primary constraint, and hierarchical solving is carried out according to time. A dispatching model is finer, so that prediction is more accurate, applicability is high, the high solving speed can be obtained on the basis of ensuring high solving precision, and the method can be applicable to large micro-grid optimization dispatching.
Owner:BEIJING BEIBIAN MICRO GRID TECH +1
Piecewise linear method for analyzing supercavitation navigation body kinetic characteristics
InactiveCN103558009AConcise parsing expressionEasy to parseHydrodynamic testingLinearizationLinear fitting
A piecewise linear method for analyzing supercavitation navigation body kinetic characteristics includes the steps that step1, a supercavitation navigation body kinetic model is built; step2, piecewise linear fitting is performed on a non-linear sliding force function in the supercavitation navigation body kinetic model to obtain a linear sliding force function; step3, parameters of the supercavitation kinetic model are set; step4, the supercavitation kinetic model with the piecewise linear sliding force Fp function is adopted for obtaining a sole balance point of a supercavitation navigation body, linearization is performed on a system at the balance point to obtain a jacobian matrix of the system and a characteristic equation at the balance point, characteristic values of the system are obtained, and the balance point of the system is judged to be an unstable saddle focus. By the adoption of the piecewise linearization of the sliding force function, the supercavitation navigation body kinetic model is simplified, so that the balance point position and stability conditions of the model have concise analytical expressions, and the supercavitation navigation body kinetic characteristics are analyzed more conveniently.
Owner:NANJING UNIV OF SCI & TECH
Natural gas network, power network and power supply combined planning method
ActiveCN106529740AAvoid difficultiesEfficient solutionForecastingSystems intergating technologiesPiecewise linearizationPower grid
The invention provides a natural gas network, power network and power supply combined planning method, comprising the steps of: firstly establishing a natural gas network, power network and power supply multi-stage combined planning model using minimum investment cost and operating cost as a goal under safety operation constraints of a power network and a natural gas network; and then transforming the optimized solution of the model into a large-scale mixed integer liner optimization problem by using an incremental piecewise linearization method, thereby quickly obtaining an optimal solution by adopting a mature mathematical optimization method, and solving the complex optimized solution problem. The method can be used in combined planning of the natural gas network, power network and power supply and provides quantitative reference basis for practical engineering problems of natural gas expansion, power network expansion and the like from the perspective of common optimized operation of the two networks, and practical engineering personnel can thus carry out relevant researches.
Owner:XI AN JIAOTONG UNIV
Economic scheduling method for micro-grid system
Owner:BEIJING BEIBIAN MICRO GRID TECH +1
Multi-unmanned aerial vehicle three-dimensional formation reconfiguration method based on artificial bee colony (ABC) algorithm
InactiveCN109669475AFast convergenceReal-timePosition/course control in three dimensionsLocal optimumPiecewise linearization
The invention discloses a multi-unmanned aerial vehicle three-dimensional formation reconfiguration method based on an artificial bee colony (ABC) algorithm, and belongs to the technical field of unmanned aerial vehicle control. The method comprises the following steps: firstly, establishing a motion model of an unmanned aerial vehicle and then giving out mathematical description of optimal time control of three-dimensional formation reconfiguration; and after piecewise linearization control input is carried out, carrying out unmanned aerial vehicle three-dimensional formation reconfigurationby using an ABC algorithm. Compared with the prior art, the method disclosed by the invention has the advantages that the searching time of unmanned aerial vehicle formation reconfiguration through the ABC algorithm is shortest, so that the rapidity of the unmanned aerial vehicle formation reconfiguration is realized; and the ABC algorithm is a global search method which can avoid falling into local optimization, so that the accuracy of the unmanned aerial vehicle formation reconfiguration is improved.
Owner:BEIHANG UNIV
Dynamic magnetic resistance based equivalent reactance transient state modeling method of magnetically controlled shunt reactor
ActiveCN101719185ANo truncation errorSolve problemsSpecial data processing applicationsShunt reactorMagnetic reluctance
The invention provides a practical decoupling electromagnetic transient state modeling method for describing the nonlinear magnetic saturation property of a super / extreme-high voltage magnetically controlled shunt reactor (MCSR), comprising the steps of: providing a transient equivalent reactance algorithm on the basis of a dynamic magnetic resistance idea under AC / DC mixed excitation; reflecting the real-time dynamic change property of the saturated equivalent reactance under the condition of the AC / DC mixed excitation; accurately describing the magnetizing and demagnetizing effect of network side AC current on a reversely series-wound DC excitation saturation magnetic circuit in two main magnetic circuits of the super / extreme-high voltage magnetically controlled shunt reactor (MCSR); describing nonlinear magnetic circuit property with arc hyperbolic functions; decoupling a coupling magnetic circuit equation; differencing transient equivalent reactance by an implicit trapezoid integration algorithm with damping; and establishing an electromagnetic transient state model. The invention not only accurately reflects the continuously smooth regulation property of the saturated magnetic circuit of the super / extreme-high voltage magnetically controlled shunt reactor (MCSR) and prevents the numerical oscillation of piecewise linearization algorithm, but also can meet the requirements of real-time / faster-than-real-time simulation computation under the condition of large-range continuous regulation.
Owner:CHINA ELECTRIC POWER RES INST +1
Full-process modeling method for oil refining process
ActiveCN104765346AAccurate and reasonable natureAccurate and reasonable operating conditionsProgramme total factory controlPiecewise linearizationSurrogate model
The invention discloses a full-process modeling method for an oil refining process. Based on the mechanisms and running characteristics of all production devices in the oil refining process and a corrected model, the influence of key operation / process conditions of all the devices on the product yield is analyzed. Piecewise linearization is carried out according to the influence trend, a linear equation is solved, corresponding Delta-Base yield data are obtained, a neural network modeling technology is combined, operation conditions and the Delta-Base data are related, a yield surrogate model is built, the yield data calculating speed is improved, real-time prediction on the product yield in the oil refining process is achieved, and theoretical supports are provided for building a precise plan optimized PIMS model.
Owner:EAST CHINA UNIV OF SCI & TECH
Device and method for realizing pulse compression of 65536 points on basis of FPGA (Field Programmable Gate Array)
ActiveCN106484658AImprove parallelismProcessing speedComplex mathematical operationsTriangular functionRotation factor
The invention belongs to the technical field of radar signal processing and discloses a device and method for realizing pulse compression of 65536 points on the basis of an FPGA (Field Programmable Gate Array). The implementation process comprises the following steps of: firstly receiving data from 16 paths in parallel, and storing the data into 16 block RAMs by adopting the principle of parallel reading and no conflict; then reading 16 numbers once by a production line mode, carrying out 4 stages of radix-16 butterfly computation and in-situ storage and finishing FFT (Fast Fourier Transform) processing; carrying out parallel and matched filtering processing on 16 paths and in-situ storage; then realizing IFFT processing by 4 stages of butterfly computation; and finally outputting for 16 paths in parallel, wherein rotation factors and matched filtering coefficients are generated in real time by using sectional linear triangular function tables and a mode of checking table differences. The device and method disclosed by the invention have the advantages that the use of RAM resources in the FPGA is greatly saved, the processing speed is obviously increased, and the data throughput is increased.
Owner:XIDIAN UNIV
Sensitivity analysis based interaction cost calculation method for microgrid and power distribution grid
InactiveCN105162113AGuaranteed economyAchieve interactionEnergy industryForecastingPositive interactionTime-sharing
A sensitivity analysis based interaction cost calculation method for a microgrid and a power distribution grid comprises the following steps of: acquiring basic structure and parameter information of the microgrid participating in interaction; forecasting the output and the load power of a distributed power supply in a scheduling period, and acquiring time-sharing electricity cost information of the power distribution grid; considering the electricity purchasing cost of the microgrid in the scheduling period, the electricity sell gain and the power generation cost of the distributed power supply by taking minimum running cost of the microgrid as a target function, and building a microgrid running optimal scheduling model; setting a constraint condition of a microgrid optimal scheduling problem; solving a microgrid optimal scheduling mode formed by the target function and the constraint condition by using an optimization tool to obtain running cost corresponding to a scheduling plan; acquiring interactive time frame information of the power distribution grid; and respectively calculating positive interaction cost and negative interaction cost of the microgrid, and acquiring the relation between the interaction capacity and the interaction cost during the positive interaction of the microgrid through piecewise linearization. By the method, the interaction between the microgrid and the power distribution grid is achieved at the minimum cost.
Owner:TIANJIN UNIV +1
Time series trend feature extraction method based on important point double evaluation factor
ActiveCN108804731AOvercome singleReduce noise interferenceArtificial lifeSpecial data processing applicationsFeature extractionRetention time
The invention discloses a time series trend feature extraction method based on an important point double evaluation factor, comprising: regarding a time series piecewise linear representation as basis, defining an important point as an alternative set of time series segmentation points, calculating an important point distance factor and a trend factor, using the distance factor to measure the relative degree of difference and using the trend factor to measure its impact on the overall trend globally, using a comprehensive evaluation model to evaluate the importance of each important point to the overall trend to select the segmentation points, and finally connecting adjacent segmentation points to obtain a segmented trend representation of the time series. The invention proposes the concept of a time series important point distance factor, and combines the two evaluation factors to evaluate the important points of the time series, which overcomes the shortcomings of single evaluation functions and locality of the existing piecewise linearization method, may effectively weaken the noise interference, retain the time series change trend feature, and has fast processing speed and higher extraction precision than the existing method when the number of segments is the same.
Owner:CENT SOUTH UNIV
Real-time prediction method for catalytic reforming device
The invention relates to a real-time prediction method for a catalytic reforming device. On-site real-time data are processed through adopting a data reconciliation technology, and an improved differential evolution algorithm is combined for carrying out real-time correction on a reforming reaction kinetic parameter, so that a mechanism model can precisely describe the actual operation condition of the device. On the basis of the corrected model, the influence on the reforming product yield caused by key operation / process conditions such as the potential aromatic content, the feeding load, the inlet temperature, the reaction pressure and the hydrogen-oil ratio is analyzed. The segmented linearization is carried out according to the influence trends, a linear equation is resolved, corresponding Delta-Base yield data is obtained, a neural network modeling technology is combined for correlating the operation conditions with the Delta-Base data, a yield agency model is built, the yield data calculation speed is accelerated, the continuous yield real-time prediction of the catalytic reforming device is realized, and the theoretical support is provided for building a precise plan optimization PIMS model.
Owner:EAST CHINA UNIV OF SCI & TECH
Design method for numerical simulation analysis platform of control system of aero-engine
The invention provides an advanced design method for a numerical simulation analysis platform of a control system of an aero-engine. Based on a MATLAB / Simulink platform, the simulation platform whichcan be used for aero-engine controller design analysis and transient state performance testing is developed. An architecture of the platform is divided into four layers, all the layers are independent, and a user can conduct targeted modification, optimization and expansion according to different simulation targets to facilitate interaction among different simulation platforms. The method has a good human-computer interaction interface, the independence of all modules is good, and separate testing of the modules and further improvement by the user are facilitated. Meanwhile, multiple methods can be adopted for the simulation platform for building an engine piecewise linearized model, and adapted to conducting optimal design on parameters of a controller, the improvement condition of the control effect can be analyzed, and the simulation platform which is accurate, efficient, universal and flexible is provided for the aero-engine and the control system thereof.
Owner:NORTHWESTERN POLYTECHNICAL UNIV
System and method for calibration of ambient light sensor brightness output
InactiveUS20070211046A1Reduce complexityReduce expensesCathode-ray tube indicatorsInput/output processes for data processingInformation processingLight sensing
Information handling system display brightness adjustments in response to ambient light sensed by an ambient light sensor are calibrated by reference to brightness levels, such as manually selectable brightness levels stored on the display. A brightness calibration module running on the information handling system or a controller of an inverter associated with the display generates an ambient light response from the manually selectable brightness levels, such as with a piecewise linearization of each pair of sequential manually selectable brightness levels. The inverter automatically adjusts display brightness by correcting ambient light levels sensed by the ambient light sensor according to the ambient light response.
Owner:DELL PROD LP
Modeling method for load characteristic simulation of power system
ActiveCN103915841AImprove the efficiency of cluster analysisImprove simulation accuracyGenetic modelsAc network circuit arrangementsProblem of timeSimulation
The invention belongs to the field of simulation modeling of power systems, and particularly relates to a modeling method for load characteristic simulation of a power system. The method comprises the steps that on the basis of actually measured load modeling, a multi-dimensional comprehensive genetic algorithm is adopted to perform identification on characteristic data of an actually measured load; power response data of an obtained model under the excitation of trapezoidal wave voltage serve as characteristic vectors for cluster analysis; in order to reduce the dimensionality of the characteristic vectors and enhance the efficiency of the cluster analysis, piecewise linearization based on time series is performed on the characteristic vectors. According to the modeling method, the problem of time-varying characteristics of a load can be effectively solved, simulation precision is improved, and a more accurate load model is provided for engineering practice.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)
Piecewise linearization optimal power flow calculation method for electricity-gas coupling system
ActiveCN110601203AEnsure safetyGood for the economyAc networks with different sources same frequencyControl theoryNatural gas
The invention discloses a piecewise linearization optimal power flow calculation method for an electricity-gas coupling system. The method comprises the steps: 1, acquiring basic parameters of a circuit element and a natural gas network element in the electricity-gas coupling system; 2, according to a fuel cost linear piecewise number Ne, converting a nonlinear original function of the thermal power generating unit fuel cost related to unit output into a linear function through employing a piecewise linearization method; 3, according to the node pressure linear piecewise number Lseg of the natural gas network, converting a nonlinear original function of natural gas network pipeline flow related to node pressure into a convex linear combination form through employing the piecewise linearization method; 4, establishing an optimal power flow model of the electricity-gas coupling system based on mixed integer linear programming; 5, solving the optimal power flow model by adopting linear programming. According to the method, the non-convex nonlinear problem can be converted into the convex linear problem, linear programming is adopted for solving, and the calculation speed is increased;and the safety of the power grid and the natural gas network is ensured, and the overall optimal economic operation can be realized.
Owner:CHONGQING UNIV
Equivalent magnetic-flow difference transient state modeling method of nonlinear magnetic circuit of magnetically controlled shunt reactor
ActiveCN101719184ANo truncation errorSave memorySpecial data processing applicationsInformation technology support systemTransient stateReal-time simulation
The invention provides a practical decoupling electromagnetic transient state modeling method for describing the nonlinear magnetic saturation property of a super / extreme-high voltage magnetically controlled shunt reactor (a high-voltage magnetically controlled shunt reactor), comprising the steps of: describing nonlinear magnetic circuit property with arc hyperbolic functions; decoupling a coupling magnetic circuit equation by providing and utilizing a magnetic-flow substitute algorithm; and establishing an equivalent magnetic-flow difference electromagnetic transient state modeling method. The invention not only accurately reflects the continuously smooth regulation property of a saturated magnetic circuit of the super / extreme-high voltage magnetically controlled shunt reactor and prevents the numerical oscillation of piecewise linearization algorithm, but also can meet the requirements of real-time / faster-than-real-time simulation computation without modifying an admittance matrix and influencing computing speed under the condition of large-range continuous regulation, provides a necessary simulation tool for the real-time electromagnetic transient state computation of the super / extreme-high voltage magnetically controlled shunt reactor and also initiates a new idea for the real-time electromagnetic transient state modeling method of a nuclear element.
Owner:CHINA ELECTRIC POWER RES INST +1
Hydraulic motor remote control system of towing winch and signal processing method thereof
ActiveCN101859121AStable output pressureUniform output pressureOperating means/releasing devices for valvesUsing electrical meansHydraulic motorProgrammable logic controller
The invention discloses a hydraulic motor remote control system of a towing winch, which comprises a remote control handle, a programmable logic controller (PLC) signal processing unit, a proportional valve controller, an electromagnetic pressure proportional valve and a hydraulic motor which are sequentially connected, wherein the electromagnetic pressure proportional valve comprises a take-up electromagnetic pressure proportional valve and a releasing electromagnetic pressure proportional valve which are connected in parallel; a signal linear processing method adopted by the PLC processing unit is a segmented linear processing method; output signals of the proportional valve controller are pulse-width modulation (PWM) signals; and the control current of the electromagnetic pressure proportional valve is 140 to 400 mA. The hydraulic motor remote control system has the characteristics of no remote control signal distortion, relatively more stable hydraulic motor output pressure, simple control method, relatively lower cost and convenient debugging.
Owner:WUHAN MARINE MACHINERY PLANT +1
A short-term optimal dispatching model considering cascade dynamic flow hysteresis
InactiveCN109190819AReduce Short-Term Scheduling DeviationForecastingResourcesHysteresisLinear relationship
The invention relates to the technical field of power grids, and discloses a short-term optimal dispatching model considering cascade dynamic flow hysteresis, which comprises the following steps: constructing an original model; constructing a mixed integer linear programming model with multiple real delays; linearizing the two-dimensional nonlinear relationship between the water level and the reservoir capacity by a piecewise linearization method. A piecewise linear method is used to linearize the two-dimensional nonlinear relationship between tail water level and discharge. The three-dimensional linear interpolation method is used to linearize the three-dimensional nonlinear relationship of the dynamic characteristic curve of the hydropower station. A mixed integer linear programming model is developed from the original model for the short-term optimal dispatch considering cascade dynamic flow hysteresis. The mixed integer linear programming model is used to optimize the dispatching of cascade hydropower stations. The invention can accurately describe the flow lag time in the short-term optimal dispatching of the cascade hydropower stations.
Owner:ELECTRIC POWER RESEARCH INSTITUTE, CHINA SOUTHERN POWER GRID CO LTD +1
High-performance real-time simulation method based on FPGA (field programmable gate array)
InactiveCN104252550AGuaranteed accuracyGuaranteed processing speedSpecial data processing applicationsElectric power transmissionFpga implementations
The invention provides a fast forming simulation method for an electric power transmission real-time simulation system. A simulator system completely based on FPGA (field programmable gate array) hardware comprises the following contents of (1) FPGA realization of electric and electronic device models: curve fitting and piecewise linearization are used for carrying out switch feature simulation; (2) FPGA realization of an electric motor: an equivalent circuit of the electric motor is analyzed, and a discretization method is used for carrying out precise simulation on the electric motor; (3) FPGA realization of rest hardware parts of an electric power transmission system: the reset hardware parts are simplified into a one-order linear model; (4) interface part design: PC (personnel computer) codes are used for completing the development. A design method from the top to the bottom is adopted, and the fast forming simulation method of carrying out primary simulation, mixed simulation and FPGA in-loop simulation on the complete electric power transmission real-time simulation system is adopted, the device modeling complexity is simplified, the exchange between a user interface module and the user information is promoted, and the operation efficiency of the system is improved.
Owner:CHINA UNIV OF MINING & TECH
Hydro-thermal generator set combination optimization scheduling method based on mixed integer programming
ActiveCN106886839ASolve the blockageImprove operational efficiencyForecastingResourcesElectric power systemPiecewise linearization
The invention discloses a hydro-thermal generator set combination optimization scheduling method based on mixed integer programming. The method comprises a step of obtaining the basic data of a single hydropower station, wherein the basic data comprises a reservoir water amount, a limit value of the reservoir water amount and a limit value of power generation flow, a step of carrying out piecewise linearization on a nonlinear constraint condition in the constraint conditions of a single hydropower station optimization scheduling model, a step of solving the single hydropower station optimization scheduling model which allows a target function F to be minimal according to a constraint condition which is subjected to piecewise linearization, a linear constraint condition of the single hydropower station optimization scheduling model and the basic data of the single hydropower station, and a step of determining a hydro-thermal generator set combination optimization scheduling model according to the single hydropower station optimization scheduling model which allows the target function F to be minimal. According to the method, the direct solution of a non-convex nonlinear problem of the nonlinear coupling of variables in time and space is avoided, and the operation efficiency of a power system is improved.
Owner:ELECTRIC POWER RESEARCH INSTITUTE OF STATE GRID QINGHAI ELECTRIC POWER COMPANY +1
Predistortion method based on memory non-linear system and predistortion apparatus thereof
ActiveCN102394846AGood linear relationshipSynchronous/start-stop systemsPiecewise linearizationComputer module
In order to maintain linearity of an input output relation of a memory non-linear system, according to a piecewise linearization idea, the invention discloses a predistortion method based on the memory non-linear system and a predistortion apparatus thereof. In the invention, a memory depth of a memory non-linear module is determined firstly, which means that present output is related with previous input at which times is determined, according to the memory depth, a relation between input of each related time and present output is obtained, and influence of a memory characteristic on the present output is fully considered. In addition, a piecewise linearization mode is employed to describe a non-linear relation between each previous time and present time output, a core idea is that a non-linear area is divided into a plurality of segments, linearization processing is adopted in each segment, and only a segment step length is reasonably set, a broken line and a curve can reach a needed approximation degree.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
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