996results about How to "Improve Simulation Efficiency" patented technology

The present invention relates to the design of an essentially digital system. As one example of digital systems, these may perform real-time transformations on time discrete digitized samples of analogue quantities. An example of such a system is a digital communication system. The transformations on the data can be specified in a programming language and executed on a processor such as a programmable processor or directly on application specific hardware. In accordance with the present invention the digital system is described as a set of threads in a description language. Alternative names for a thread are tasks and processes. The set of threads defines a representation or model of the digital system. In accordance with the present invention, the representation or model is preferably executable at each stage of the design independent of the current level of abstraction of that representation or model. With description language is meant a programming language. In accordance with the present invention each of the threads has a variable having an assignable value which represents the “local time” of said thread, i.e. a time associated only with that thread, which can be used for sequencing the processing of that thread with respect to other threads. With the word “local” is meant that the time is an attribute of the thread only. In accordance with the present invention a means is provided for the designer to assign a delay to each thread or operation within a thread, this delay representing for instance the processing time for the respective operation or thread on a processing engine, e.g. a computer. By this means, not only can the processing of threads be scheduled but also the designer may assign a value representative of an elapsed time for the processing of a thread or operation on a processing engine. In addition, the threads may be refined concurrently, while still keeping their local time so that after the refining process the new representation of the digital system is executable, i.e. the processing of the refined threads can be scheduled without divergence from the specification.

The invention relates to a method and a system for a semi-physical simulation test of visual unmanned aerial vehicle flight control and belongs to the technical field of visual system simulation. The method includes building a dynamic model of an unmanned aerial vehicle system, initializing the dynamic model, enabling an unmanned aerial vehicle to fly along the track provided by the ground, feeding flight rudder quantity information to the dynamic model to be updated, driving a three-dimensional model of the unmanned aerial vehicle through the updated dynamic model to conduct simulation and outputting simulation image and data in real time. A system based on the method is further provided. The method and the system provide effective ways and development environment for design, experiments and verification of the flight control law, have the advantages of being simple, flexible, quick, vivid and real-time, improve simulation efficiency of a flight control system, reduce test risk and test cost of the unmanned aerial vehicle and shorten development period.

The invention provides an active reliability analyzing and evaluating method for highly-reliable mechanical products. The active reliability analyzing and evaluating method for the highly-reliable mechanical products includes: firstly, establishing ultimate state functions of mechanical products, utilizing a Monte Carlo simulation method to produce sample points conforming to parameter distribution, utilizing a Kriging meta-model to simulate the ultimate state functions, improving simulation precision and confirming an optimal sampling radius by automatically updating DOE (design of experiment), constructing important sampling density functions, producing random sample points through the important sampling density functions, updating the DOE continually, then extracting radius random sample points obeying chi-square distribution, confirming failure probability and failure coefficient of variation of the mechanical products, and limiting whether updating finishes or not by the failure coefficient of variation so as to obtain reliability of the mechanical products finally. The active reliability analyzing and evaluating method for the highly-reliable mechanical products has the advantages of high efficiency, good robustness and high simulation precision, comprehensive design and analysis of rail wear life and reliability to spatial mechanisms are achieved, and the active reliability analyzing and evaluating method for the highly-reliable mechanical products is significant to reliability design technology engineering of complex mechanisms of aerospace equipment.

The invention provides a simulation modeling method for equivalent simulation of a doubly-fed wind-power generator set. A frequency converter of the doubly-fed wind-power generator set is simulated by controlled source. The simulation modeling method includes the following steps of (1), building a model of a circuit of the doubly-fed wind-power generator set; (2) building an equivalent model of the doubly-fed wind-power generator set; (3) building a grid-integration testing system of the doubly-fed wind-power generator set; and (4) setting up a testing system for multiple wind-power generator sets, wherein in the step (2), the equivalent model of the doubly-fed wind-power generator set is built on the basis of characteristics of a controlled voltage source of an alternating-current side and a controlled current source of a direct-current side of the frequency converter of the doubly-fed wind-power generator set. By the aid of the simulation modeling method, transient-state characteristics of the doubly-fed wind-power generator set can be simulated accurately, and different characteristics and mutual affection among multiple wind-power generator sets can be computed. High-frequency on and off of fully-controlled devices cannot be taken into consideration, and simulation efficiency is improved greatly. The more the wind-power generator sets are simulated, the more evidently the efficiency is improved, simulation step-length can be increased on the premise of guaranteeing accuracy, and simulation efficiency is improved greatly.

The invention discloses a visualization cooperative sharing method for simulation data in network environment, belonging to the technical field of data visualization for simulation data network communication. The method is characterized in that a simulation data visualization processing module is created at the server side to provide users a parameter submission interface and a processing engine, thus realizing visualization processing the simulation data document according to the necessary parameters, and a simulation data cooperative sharing module is created to provide users a public virtual environment, thus realizing a remote simultaneous display; a common browser is used at client side to provide an operating interface and the visualization parameters are sent to the business logic class in the visualization processing module for visual processing through the parameter submission interface and the processing result is cooperative displayed and annotated in an end to end model between client sides and between the client side and the server. The invention fills in the blank of simulation data visualization and cooperative sharing in network environment.

The present invention relates to a multi-processor satellite real-time simulation platform which consists of three or more than three ARM processors, and two or more than two DSP processors with an FPGA as an intermediate memory. The ARM1 is used as the computer of the simulation satellite control center; the ARM2 is used in the space environment of the simulation satellite; the ARM3 is used for the kinetic calculation of the satellite; the DSP1 is used for completing the calculation of a sensor model; the DSP2 is used for completing the calculation of an actuating mechanism; the ARM1 sends data to the DSP1 so as to acquire instructions; the DSP1 sends the acquired data instructions to the ARM2 and the ARM3, fetches relevant data from the FPGA, and transmits the data to the ARM1; the ARM1 completes the calculation according to the read data, and acquires the corresponding attitude orbital parameters; if the parameters satisfy the requirements, the satellite enters the normal mode; if the parameters do not satisfy the requirements, the ARM1 sends control instructions to the DSP2 so as to control the actuating mechanism; the DSP2 transmits the corresponding data to the ARM2 and the ARM3 through the FPGA after completing the calculation, until the attitude orbit can satisfy the corresponding requirements. The platform simplifies the complexity of the system, lowers the difficulty of the simulation, and improves the real-time performance of the simulation.

The invention discloses an evaluation method of reliability of an aerospace electronic product based on a failure mechanism. On the basis that an analysis method with a combination of physical simulation and a test is adopted, a physical simulation model of the electronic product is constructed, the means such as sensitivity analysis, Monte Carlo analysis, and stress analysis are adopted, and product key elements are identified and in combination with actual working conditions of the elements, a failure mechanism analysis is conducted. Currently, the failure mechanism analysis aiming at the elements is a means used for analyzing a failure reason after a failure occurs during the test or in the using process of the electronic product, thus pertinent improvement is conducted on the product, the service life of the product is prolonged, and the reliability of the product is improved; the failure mechanism analysis aims at finding key characteristic parameters which affect the service life and the reliability of weak elements as an independent variable of the reliability model.

The invention relates to a single even effect cross section obtaining method based on simulation. The single even effect cross section obtaining method comprises the following steps of: setting an actual material structure, geometric structure and doping parameters of a device, and realizing a complete device model; carrying out semiconductor characteristic numerical calculation, solving a diffusion drifting equation, a poisson equation and a current carrier continuity equation, and obtaining an electricity characteristic curve of the device; and calibrating key electrical parameters of a single even effect device model so that the device electricity is in line with theoretical expectation, wherein the key electricity parameters include a transistor transfer characteristic curve and a storage delay characteristic curve. The single even effect cross section obtaining method based on simulation, provided by the invention, has the advantages that the position of the single even effect error can be located, the relationship among the wiring and size of the device, the technological parameter of the device and the sensibility of the single event effect can be realized, and the confirmation of the single even effect performance can be realized in the design stage.

The invention discloses a modular multilevel converter (MMC) topology converter efficient electromagnetism transient state simulation method. The method comprises the following steps: (1) building a thevenin equivalent circuit of a submodule and acquiring the hevenin equivalent circuit of a series subnodule, (2) opening power system computer aided design (PSCAD) and operating Fortran script editing user-defined module, (3) replacing at least one submodule by using the user-defined module, (4) using status bit to show insulated gate bipolar transistor (IGBT) status in the user-defined module of the PSCAD, (5) and figuring submodule capacitor voltage and submodule current by using a difference equation. The method reduces the number of nodes of a MMC topology converter model, and is quick in simulation speed and high in efficiency.

The invention discloses a double-turntable five-axis numerical control machine tool virtual assembling and numerical control machining simulation method and provides a simulation method capable of improving simulation efficiency under the premise of guaranteeing simulation correctness. The method includes: modeling; conducting three-dimensional modeling of blanks and clamps required in all moving components, a machine tool body and numerical control machining; connecting all moving components and the machine tool body to conduct virtual assembling according to a moving relation by using a Pro / E three-dimensional platform; operating a virtual simulating machine tool; outputting models of all components in a standard template library (STL) form on the basis of the same coordinate system; establishing a double-turntable five-axis numerical control machine tool virtual model; establishing a model tree in VERICUT, and the sequence of model components includes two branches: machine tool body Base - Y axis - X axis - A axis - C axis - clamp - blank and machine tool body Base - Z axis - main axis - tool; the STL assembly model output by Pro / E is led into corresponding components in VERICUT directly, namely the double-turntable five-axis numerical control machine tool virtual model is established; and numerical control machining simulation is operated.

The invention discloses a flight simulation test system for a solid-liquid power aircraft. The flight simulation test system for the solid-liquid power aircraft comprises an integrated console system, an aircraft simulation model system and a data processing system. The integrated console system is mainly used for setting system parameters, monitoring key variables and status information, starting and controlling programs, checking operation instructions and the like. The aircraft simulation model system is mainly used for conducting operation calculation of each system model. The data processing system is mainly used for achieving the simulation data processing function and the simulation data storage function. According to the characteristics of the solid-liquid power aircraft, the flight simulation test system mainly achieves the following functions that firstly, simulation ballistic trajectories can be set according to the task requirements; then, diversification control rate can be set and an efficiency test can be conducted; finally, the real-time monitoring function and the storage function of the status of the system can be achieved.

The invention belongs to the technical field of unmanned driving, and discloses a target following and dynamic obstacle avoidance control method for a speed difference slip steering vehicle, and the method comprises the steps: building four neural networks through employing a depth determinacy strategy in reinforcement learning; constructing a cost range of the obstacle so as to determine a single-step reward function of the action; determining continuous action output through an actor-critic strategy, and updating network parameters continuously through gradient transmission; and training a network model for following and obstacle avoidance according to the current state. According to the method, the intelligence of vehicle following and obstacle avoidance is improved, and the method canbetter adapt to an unknown environment and well cope with other emergencies. the complexity of establishing a simulation environment in the reinforcement learning training process is reduced. By utilizing a neural network prediction model trained in advance, the position and posture of each step of the target vehicle and the obstacle can be obtained according to the initial position and posture ofthe target and the obstacle and the action value of each step, so that the simulation accuracy and efficiency are improved.

The invention relates to a transient stability distributed simulation method of an electric power system, belonging to the transient stability analysis technical field of the electric power system; the transient stability distributed simulation method is characterized in that: variable dimension of boundary coordination equation is reduced to one half of that of a partitioning method based on connecting line by using the partitioning method based on a node decomposing method, so as to improve the simulation efficiency; the accurate initial Jacobi inverse matrix is obtained by using a boundary perturbation method, so as to reduce iterations; the calculation process is accelerated by comprehensively adopting the methods that the boundary node voltage value of the next time step is pre-estimated and the Jacobi inverse matrix is coordinated and dynamically updated simultaneously in multiple time steps; by adopting coordination algorithm based on inverse Broyden quasi-Newton method, the solving times of the boundary coordination equation are reduced greatly, so as to improve the simulation efficiency. In the technical proposal, the data interface is simple, the data transmission capacity is low, the system model is simplified, superlinear convergence speed close to the newton method is provided, and hyper real-time simulation can be realized in a wide area communication network, therefore, the method is conveniently applied to the practical electric power system.

The invention discloses a numerical reservoir simulation method for measuring the flowing situation of a plurality of intersected discrete cracks. The method comprises the steps that a reservoir is divided into a continuous medium and a discrete crack medium; in order to remove extremely small grids, when a reservoir grid is created, a discrete crack endpoint is deformed or is simplified to be a segment by neglecting the thickness, then a rock stratum face grid is established, and a three-dimensional reservoir grid is established; practically measured reservoir parameters of holes, leakage, saturation and the like are input into a simulator, then a real value instead of a grid display value is used as the width of each discrete crack, and accuracy of a measured and calculated result is not lowered by deformation processing; the volume of the intersecting area of the discrete cracks is neglected, and a flow formula of the discrete cracks in the intersecting area is established; the reservoir parameters are corrected by utilizing the history fitting method; then well yield and remaining oil gas distribution and reserves are measured and calculated. The numerical reservoir simulation method can solve the problems that the discrete crack value simulation technology is prone to interruption and failure and is long in consumed time for measurement and calculation, so that the technology can achieve measurement and calculation in the whole process of full three-dimensional reservoir development, and improves accuracy of the measured and calculated result.

The invention provides a multi-domain collaborative distribution type simulation system comprising a main control module, a data service module and a model interface module. The main control module is used for loading description documents of a preset model to obtain corresponding model information, setting clock fundamental frequency according to the model information, issuing the clock fundamental frequency and simulation control demands, arranging data transmission channels between the models in the data service module according to the model information, and defining data update periods of data channels. The data service module is used for establishing a data link which has an independent data transmission period, and providing the data channels for collaborative distribution type simulation data. The model interface module is used for establishing a connection relationship and schedule management of the main control module and a simulation sub-engine, and sending the clock fundamental frequency and the simulation control demands to the simulation sub-engine to complete calculation of the corresponding models. The multi-domain collaborative distribution type simulation system supports derivation of all simulation soft wares, and has the advantages of being high in calculation precision of collaborative simulation and high in calculation efficiency, and collaborative simulation is not prone to be caused.

A method for simulating large circuits in full-scale. To enhance the simulation efficiency, subcircuits are extracted from a circuit and thence a hierarchical structure is established using the extracted subcircuits. Subsequently, the circuit is partitioned and a current-voltage table for each subcircuit is dynamically generated. A transient analysis of the circuit is preformed at each incremental time step and a recursive latency check is preformed from the top to the bottom level of the hierarchical structure to determine the active part of the circuit. Using the current-voltage curves, a portion of the conductance matrix corresponding to the active part is rebuild at each incremental time step, which significantly reduces the simulation time.

The invention provides a time domain analysis method for a transient response of lossy nonuinform multi-conductor transmission lines and aims to solve the problem that the coupling among the lossy nonuniform multi-conductor transmission lines interferes with the computation in the field of integrity of electronic circuit signals. The method comprises the following steps of: performing differential dispersion on space differential operators in an electric wave equation; and integrating time differential operators in the electrical wave equation by a trapezoidal integration method to ensure that the oscillation, which is caused by a central difference method, of a computed result can be eliminated effectively, voltage and current transient response waveforms of any point on the transmissionlines can be acquired; and the transient analysis of the transmission lines in a longer time period is effective, the waveforms can be analyzed in a longer duration without large errors, and the coupled transmission lines are not needed to be decoupled when a model of the transmission lines is built. By the method, the computational load is reduced, and the simulation efficiency is improved. The method can be used for analyzing the transient response of the lossy nonuinform multi-conductor transmission lines.

The invention discloses a time synchronization and data exchange apparatus and method used for combined simulation of a power system and an information communication system. The time synchronization and data exchange apparatus comprises an information communication system simulation synchronization apparatus and a power system simulation synchronization apparatus. A "peer-to-peer" synchronous system framework is adopted, so that both an information communication simulator and a power system simulator can flexibly and actively send data. An event queue is arranged on each of two sides and used for forwarding data with a time stamp and event starting time, and also serves as a "synchronous time axis", so that two simulation platforms are enabled to keep time synchronous while the data is transmitted. In a simulation process, the two simulators concurrently execute respective simulation tasks by reference to the "synchronous time axes" on the own sides, and when the speeds of the two simulators are not matched, the two simulators are suspended for waiting for each other.

The invention provides a design method for an axial flow impeller machine for confirming the flow model of the axial flow impeller machine. The method at least includes the circle component of vu2 and axial plane speed of vm2 which are at the exit of a vane and are distributed in a way of linearity along the radius of the vane, and the circle component and axial plane at the hub side is small while the circle component and axial plane at the wheel edge side is larger; the distribution functions of the circle component vu2 and axial plane speed vm2 at the exit of the vane are confirmed according to the external characteristic parameters and structure parameters as well as the flow model of the axial flow impeller machine; the axial flow impeller machine is designed according to the confirmed distribution functions of the circle component vu2 and axial plane speed vm2 at the exit of the vane. The invention also provides the vane of the designed axial flow impeller machine; wherein, the difference of the mounting angles for the wing models of the hub side and wheel edge side of the vane Delta Beta is equal to Beta h minus Beta s and is between minus 3 degrees to 10 degrees. The equipressure area at the back of the vane is distributed along the radial direction of the vane in strip. The invention can improve the efficiency of the impeller machine to reach 91 percent and improve the anti-cavitation erosion capacity.

The invention belongs to the technical field of a multiple-input-multiple-output system and discloses a MassiveMIMO channel modeling method based on measured data. According to the method, a confocal elliptical model is established, and base station and dipole parameters are set; a birth and death rate of a scattering cluster is acquired according to the measured data to acquire a nine-state Markov chain state transfer probability matrix, an evolution process of the scattering cluster on an antenna array axis is described through utilizing a Markov chain, and characteristic parameters of each scattering cluster are distributed; and lastly, according to the geometric position relationships among the parameters, phase and Doppler frequency under the stadia and non-stadia conditions can be calculated, and channel impulse response is generated. The method is advantaged in that the birth and death process of the scattering cluster on the antenna array can be accurately described, non-stationary characteristics of a MassiveMIMO channel is reflected, spherical wave characteristics can be described, moreover, computational complexity is relatively low, the channel impulse response can be generated in relatively short time, and channel simulation efficiency is improved.

The invention discloses a method for improving an oil reservoir exploitation effect by utilizing discrete fracture endpoint deformation numerical simulation. The method comprises the following steps of dividing an oil reservoir storage body into a continuous medium and a discrete medium according to a characteristic scale; deforming the end part of a discrete fracture from a square shape into a pointed shape to eliminate tiny grids, establishing rock stratum surface grids, and establishing three-dimensional oil reservoir grids; inputting measured oil reservoir parameters such as porosity, permeability and water saturation into a simulator, wherein a real value rather than a grid display value is used for the width of the discrete fracture; correcting the oil reservoir parameters by using a history matching method; and measuring and calculating the well productivity, residual oil and gas reserves and the distribution positions of residual oil and gas, and making a subsequent oil reservoir exploitation plan. According to the method, a discrete fracture numerical simulator can be prevented from measurement and calculation interruption and failures, the whole links of oil reservoir exploitation can be actually measured and calculated to improve the measurement and calculation accuracy of the well productivity and the residual oil and gas distribution of an oil reservoir, and a more effective development plan can be made to improve the oil reservoir exploitation effect.

The invention relates to a breakpoint simulation controller and a breakpoint simulation control method for a ground simulation system. The controller comprises a breakpoint monitoring storage module, a data recovery module and a time synchronizing module; under the semi-physical simulation condition, the breakpoint monitoring storage module records the global variable of the simulation system; when the simulation restarts, the data recovery module takes the data as input, so that continuation of system simulation is realized, the simulation efficiency and the simulation effect are greatly improved, and massive time, energy and cost are saved; meanwhile, the controller comprises the time synchronizing module, so that synchronization of accuracy record and recovery time of the system operating breakpoint is ensured; and by using the controller and the method, judgment of multi-process breakpoints of the complex simulation system is solved, the process data are stored in time, and data and means are provided for recovering the operation of the system.

The embodiment of the invention provides a semi-physical simulation system and a semi-physical simulation method. The system comprises a physical device, a physical effect device for providing a simulation work environment for the physical device, a data transmission device and a simulation excitation device connected with the physical device and the physical effect device through the data transmission device. The simulation excitation device is used for loading a simulation model with the simulation requirement currently, acquiring device control parameters, device initialization parameters and initial simulation parameters which are preset for the simulation model, controlling the physical device and the physical effect device according to the device control parameters, initializing the physical effect device according to the device initialization parameters, operating the simulation model and conducting semi-physical simulation through the initial simulation parameters and in combination with the physical device and the physical effect device. By the adoption of the system and method, resources are saved and simulation efficiency is improved.

The invention discloses a fuel cell stack modeling method with a fluid non-uniform distribution effect. Establishment of a model comprises three parts: a fluid network model, a single cell mechanism model and coupling of the fluid network model and the single cell mechanism model, wherein the fluid network model is used for calculating the pressure drop loss of each part to obtain the actual flowof gas flowing into each single cell and the actual distribution condition of the cooling liquid; the single cell mechanism model calculates the membrane water content, the liquid water volume fraction, the gas components, the temperature and the like at the center of each layer, and can reflect the gas concentration and the temperature distribution in each single cell; and through coupling of thetwo models, the distribution condition of the reaction gas in the electric pile can be accurately calculated, and meanwhile, an electric pile model of the internal parameter distribution condition ofeach single cell can be provided. According to the method, the defect of low model accuracy caused by excessive simplification of a previous fluid network model on a heat and mass transfer mechanismin each single cell is overcome, and the problem of low simulation efficiency of the three-dimensional galvanic pile model is also solved.

The invention discloses a large-volume concrete multi-field real-time online collaborative intelligent simulation method and a large-volume concrete multi-field real-time online collaborative intelligent simulation system. The method comprises the following steps: step S1, a sensing step of model establishment and real sensing input; S2, an analysis step of initializing parameters to be determinedand performing simulation calculation analysis; S3, an evaluation step of evaluating the truth degree of the simulation result; S4, a feedback step of judging simulation results and making process optimization adjustmentst; S5, a control step of performing closed-loop intelligent control; and S6, a learning step of learning the above steps, and starting a new loop. Through dynamic circulation ofthe steps, the frequency and precision of traditional simulation analysis and the application efficiency of simulation results are improved. Real perception, intelligent analysis and dynamic control of simulation objects are achieved, and the method can be applied to intelligent construction, full life cycle simulation analysis and the like of large-scale civil engineering and water conservancy structure engineering.

The invention discloses a multi-rate simulation method and a multi-rate simulation device for a power-electronizing power system. The method comprises: dividing the power-electronizing power system into a slow subsystem and a plurality of fast subsystems; establishing equivalent models respectively; setting simulation parameters; performing power flow calculation on the power system to obtain a steady-state initial value of the power system; establishing interfaces between the plurality of fast subsystems and the slow subsystem, and establishing a time-varying Thevenin equivalent circuit and a time-varying Norton equivalent circuit; and obtaining interface parameters according to the established time-varying Thevenin equivalent circuit and the established time-varying Norton equivalent circuit, and parallelly solving node admittance equations corresponding to the equivalent models of each fast subsystem and the slow subsystem until simulation ends up so as to obtain an electromagnetic transient state simulation result. By the simulation method provided by the embodiment of the invention, the non-linear dynamic characteristics of the internal part of an alternating current system or a direct current power grid can be maintained; meanwhile, the simulation efficiency is obviously improved relative to a single step length result.

The invention provides a method for quickly simulating airborne phased array pulse Doppler (PD) radar clutter. The method comprises the following steps of: selecting a synthetic aperture radar (SAR) image; dividing the whole clutter scene into rectangular scattering units, and regarding each scattering unit as a point scattering body distributed in the center of the unit; acquiring the initial backscattering coefficient of each scattering unit; dividing the clutter scene into equidistant rings; upsampling a transmitted signal of a PD radar, and performing fast Fourier transform (FFT) on an upsampling result to obtain U(omega); calculating the amplitude A of each scattering unit; calculating the radar backscattering coefficient of each equidistant ring; acquiring an impulse response function of a system, and performing FFT on the function to obtain H(omega); and multiplying U(omega) by H(omega), and performing inverse FFT on a multiplication result to obtain a clutter signal received in a period corresponding to a transmitted pulse. By the method, natural scene clutter is quickly simulated in the airborne PD radar system under the condition of high resolution.

The invention discloses a fast Realization method for simulation 3D scene SAR radar echo based on forward method. The main idea of the fast Realization method comprises the following steps: acquiring digital elevation model (DEM) data within SAR radar beam range, wherein the data comprises K point targets; randomly distributing the K point targets on a 2D ground in the geographic coordinate system, and calculating DEM data within the SAR radar beam range after refinement processing; acquiring back scattering property distribution of the DEM data within the SAR radar beam range after refinement processing; utilizing an improved downward angle comparison method to determine shaded areas of Q small surface elements, calculating final actual back scattering coefficients of the Q small surface elements after shaded area determination, and then calculating SAR radar echo of the Q small surface elements. At this time, the whole 3D scene echo simulation is completed in a graphic processing unit (GPU), and finally an echo signal in the GPU is sent to a CPU processor to be output.

The invention discloses a hierarchical dynamic equivalence method suitable for a regional power grid. The method comprises the steps of dividing a large-scale power grid into an internal system and an external system; building a power grid model of the internal system according to a topological structure of the internal system; dividing the external system into three layers of an outer-layer external network, an inner-layer external network and a buffer network; building an equivalent model of the outer-layer external network by adopting a coherent equivalence method; building an equivalent model of the inner-layer external network by adopting a dynamic equivalence method based on physical equivalence; building a power grid model of the buffer network according to a topological structure of the buffer network; simplifying 500kV backbone networks in the equivalent model of the outer-layer external network and the equivalent model of the inner-layer external network to the boundary of the buffer network by adopting a backbone network simplification method, and forming an equivalent model of the external system by the equivalent model of the outer-layer external network, the equivalent model of the inner-layer external network and the power grid model of the buffer network; and combining the power grid model of the internal system with the equivalent model of the external system to finally obtain an equivalent model of the regional power grid. According to the method, the simulation efficiency and the equivalence precision are ensured.