165results about How to "Guaranteed Simulation Accuracy" patented technology

The invention provides a small interference stability simulation method of an electric power system, which can effectively utilize resources of a plurality of CPUs or a multi-core CPU processor in a computer, thus greatly improving the simulation efficiency. The method comprises: first, calculating the number of searching points of characteristic values, and automatically assigning calculating tasks with certain searching points of the characteristic values for every CPU core according to the number N of the CPU cores; then, calling fork( ) function under a linux system to generate N courses,and simultaneously calling the corresponding CPU core to independently execute the calculation of a searching point set by all sub-courses, thus realizing concurrent computation. After all the sub-courses complete the calculation, computing results of all the sub-courses are collected by main program for outputting the results.

The invention discloses a simulation method of an MMC (modular multilevel converter). The simulation method comprises the following steps: (1) obtaining operation parameters of an SM (Submodule); (2) construction an equivalent circuit of SM; (3) establishing an artificial circuit of SM; and (4) establishing a simulation system of MMC and simulating the system. According to the simulation method provided by the invention, by the utilization of numerical calculation and electromagnetic simulation internal mechanism, the SM in the MMC can be equivalent to a simple branch formed by a controlled voltage source and an adjustable resistor effectively, and the number of nodes of the system and the corresponding simulation calculation can be greatly reduced, so that on the premise that the simulation precision is ensured, the simulation speed of the MMC is greatly promoted, and the method is applied for MMC design.

The invention provides an emulational simple target simulation system for visible image guided missiles. A projector is adopted to project target crosses to a projection curtain; a control computer is adopted for controlling the yawing and pitching direction angles of a triaxial turntable; a visible light guiding head is adopted for detecting the target crosses; a target display computer is adopted for target simulation; the yawing direction angle and the pitching direction angle of an externally input simulation target relative to the center of the triaxial turntable are received, the position coordinates of the cross targets in the projection image can be calculated and obtained according to a two-dimensional mapping table stored inside, and the projector is controlled to project the cross targets to the projection curtain according to the position coordinates; a calibration computer is adopted for calibration; a two-dimensional mapping table in which the yawing direction angle and the pitching direction angle of the triaxial turntable are in one-to-one correspondence with the cross targets is built and then sent to the target display computer. The system can realize simple image generation and guarantee a certain simulation precision.

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 flow distortion simulation device which comprises a tank body, a tube body, a motor, a worm, a bevel gear assembly, a worm gear, a lead screw, a guiding rod, a linear bearing, a gear nut, an inserting plate, a displacement detection assembly and a controller. The tube body is arranged on the tank body, the worm is arranged in the tank body, the bevel gear assembly is respectively connected with the motor and the worm, the worm gear is arranged on the worm, the lead screw is meshed with the worm gear, the linear bearing is arranged on the guiding rod, the gear nut is arranged on the guiding rod and is in screw-thread fit with the lead screw, the inserting plate is respectively connected with the linear bearing and the gear nut, and the controller is respectively connected with the displacement detection assembly and the motor. The flow distortion simulation device has the advantages of being capable of meeting requirements of a turbofan engine inlet distortion resistant test and an engine surge test, small in occupied space, continuous and adjustable in distortion index, convenient to install and operate, high in simulation accuracy and degree of automation, capable of improving the test efficiency, reducing the test cost, reducing the workloads of people and the like.

The invention discloses a trailing vortex field transfer based numerical simulation method for a multi-aircraft flight formation. The method comprises: according to a mathematical model of a surface contour of an aircraft model, generating a front and a rear aircraft computing grid, wherein each of the front and rear aircraft computing grids contains transition block grids that have same topological structures; computing flow field data of a front aircraft in a free boundary state; exporting trailing vortex field data of the transition block grids of the front aircraft after computational convergence of the flow field data of the front aircraft; reading the exported trailing vortex field data of the transition block grids of the front aircraft into the transition block grids of a rear aircraft; and computing flow field data of the rear aircraft by using the read transition block grid data as a boundary condition. According to the method disclosed by the invention, a relatively small number of computing grids are adopted for numerical simulation; and meanwhile, a spoiler field result of a front aircraft model can be used for computing different spanwise/flow positions and different flight attitudes of the rear aircraft, thereby avoiding multi-time computation of the front aircraft model in conventional computing.

The invention discloses a discrete state event-driven simulation method for power electronic hybrid system simulation. Based on the hybrid characteristics of a power electronic system, a simulation method is designed for a continuous state and a discrete event coexisting in the power electronic system. The simulation method comprises a flexible adaptive algorithm with variable order and step sizeand an event-driven mechanism which automatically triggers simulation calculation through the discrete event. The continuous state is described by a state variable method. The discrete event is defined as a trigger source of simulation calculation. The discrete state event-driven simulation method for power electronic hybrid system simulation solves the problems of large simulation computation andlong time of a complex power electronic system under the premise of ensuring accuracy.

The invention provides an ADPSS-based distributed power flow controller modeling and simulation method. Electromagnetic transient simulation of a distributed power flow controller on a power system digital simulation system ADPSS platform can be realized. The method comprises the steps that a double-loop power transmission system simulation model is established under the ADPSS/ETSDAC simulation environment, a DPFC device is appropriately simplified by using the UDM function module of the ADPSS/ETSDAC, a series side current converter equivalent mathematical model is established by using an equivalent voltage source, and a parallel side current converter equivalent mathematical model is established by using an MMC mean value model. The dynamic and static characteristics of the DPFC device and the regulation and control function for the system power flow can be reflected under the premise of guaranteeing the simulation scale so that the simulation accuracy can be guaranteed and the simulation time can be shortened; and the more reliable, more comprehensive and more detailed theoretical support can be provided for actual power grid safe and stable operation of the DPFC device, and the foundation can be laid for popularization and application of the distributed power flow controller.

The invention belongs to the technical field of a water environment simulation method, and particularly relates to a method for predicating and analyzing the water quantity and quality coupling simulation in an oversized river basin. The method comprises river basin multi-box division, single-box pollution check computation, single-box water quantity and quality coupling mode establishing, multi-box nesting and multi-box water quantity and quality coupling simulation. The method is mainly characterized in that a box body model and a water quantity and quality coupling theory are integrated into an oversized river basin (such as the Three Gorges river basin, the Yangtze river basin, large-scale lakes and water reservoirs) water quality simulation process so as to carry out system simulation and predication on water quantity and quality conditions in the oversized river basin. The method disclosed by the invention has the advantages that the computation is efficient, the operation is convenient, the requirements on data information are less, the complex problems caused by size difference and uncertainty are effectively treated, the technical defect of the water quantity and quality coupling simulation of the oversized river basin is filled, and information such as water pollution situation is provided for river basin management.

The invention provides an implicit expression trapezoidal integral electromagnetic transient modeling method with damping of a double-fed asynchronous motor. The method comprises the steps of (1) starting from a three-phase circuit equation and a flux linkage equation, obtaining a circuit equation through park transformation, using the implicit expression trapezoid integration method with the damping for carrying out differencing on the circuit equation, and obtaining a thevenin equivalent circuit on the stator side and the rotor side of the double-fed asynchronous motor; (2) putting forward an interface method of the double-fed asynchronous motor and an external electromagnetic transient network, and connecting the double-fed asynchronous motor and the external electromagnetic transient network with an external network in a stator side and rotor side three-phase injection current source and an admittance matrix mode; (3) using the implicit expression trapezoid integration method with the damping for carrying out differencing on a rotor movement equation of the double-fed asynchronous motor to obtain a rotation equation of the double-fed asynchronous motor with multiple mass blocks, and achieving implicit expression trapezoidal integral electromagnetic transient modeling and calculation with damping of the double-fed asynchronous motor through iterative computations. According to the implicit expression trapezoidal integral electromagnetic transient modeling method with damping of the double-fed asynchronous motor, the electromagnetic transient simulation accuracy of the double-fed asynchronous motor model is improved, and the modeling stability is improved.

The invention provides a background grid adaptive segmenting method in a DC resistivity no-unit method. The method comprises the following steps of determining distribution condition of medium, abnormal member, landform, electrode and the like in a two-dimensional ground electric model, establishing a DC resistivity no-unit method calculating domain, and utilizing an irregularly distributed node discrete ground electric model; covering the calculating domain by means of a small number of rough and simple initial quadrangular grids, setting a control value which guides adaptive segmentation, and performing adaptive segmentation by the background grid according to the control value and a node distribution condition; arranging ng Gaussian integration points xg in each background grid, and obtaining a no-unit method equation set of the region; solving the equation set for obtaining a node electric field value, and calculating the vision resistivity parameter of a viewing point. The methodcan be based on any node distribution discrete model. High adaptability for any complicated ground electric model is realized. The background grid adaptive segmenting method improves value stability and computing efficiency in routine DC resistivity no-unit method forward calculation.

The invention discloses a modeling and simulating method of a carrier-based aircraft seat strap restraint system, and belongs to the field of aviation biomechanical simulation. Firstly, a finite element model of a seat is built by referring to a certain type of carrier-based aircraft through three-dimensional modeling software and a hybrid grid; the initial state of a Hybrid 3 type dummy model is set according to a standard posture; a hybrid safety belt mode is used, a multi-body model is used from a tensioning mechanism to the shoulder, and the finite element model is used on rest portions; then, the seat, a dummy and a strap model are combined into a human seat strap system model, a seat back inclination angle is set according to the posture in an actual carrier-based aircraft, it is assumed that the seat and the aircraft are in rigid connection, and the contact between the seat and a person and the contact between the seat and the strap are established; finally, according to the blocking carrier landing accelerated speed of the actual carrier-based aircraft, an accelerated speed curve of a bottom plate serves as an input curve of simulation analysis to be applied to the bottom of the seat and input to a calculation model for simulation calculation. The method is capable of evaluating the restraint effect of the strap system and safety risks to pilots.

The invention discloses a simulation system and a calibration method for hydrodynamic power of a parallel pump system of a primary coolant circuit of a reactor and aims to solve the problem of inaccurate simulation result when an existing simulation pump path is used for simulating flow distribution manners and hydraulic characteristics under working conditions of forced circulation, natural circulation and interconversion between forced circulation and natural circulation. The simulation system comprises a main pump simulating branch and a spare pump simulating branch in parallel connection with the main pump simulating branch, wherein the spare pump simulating branch comprises a parallel connection pipeline (1) and a first resistance adjusting piece (2), a first check valve (3) and a first flow meter (4) which are arranged on the parallel connection pipeline (1). The simulation system provided by the invention has the advantages that the hydraulic characteristics of a parallel pump path under various conditions can be completely and accurately simulated, the test cost can be effectively reduced and the simulation accuracy can be effectively increased.

The invention relates to an active distribution network fault recovery method with consideration of random variation of distributed power supply outputs. The method is characterized by comprising thefollowing steps: step one, carrying out active distribution network island division based on a depth and breadth alternate joint strategy; and step two, on the basis of comprehensive consideration offault recovery whole-period flow changes, carrying out active distribution network reconstruction optimization by using a low-offset stochastic simulation method. Therefore, the maximum output of theDG is utilized fully and loads are recovered as many as possible; and uninterrupted power supply of important loads is ensured.

Provided is a modeling and simulation method for a terahertz quantum cascade laser circuit considering a heat effect. The theoretical calculation formula of the single-stage optical gain coefficient G of a THzQCL active layer, a corresponding electron rate equation and a corresponding photon rate equation are built, the heat rate equation of a THzQCL is built, the physical equation model representing the internal carrier transport of the THzQCL and the heat effect is obtained through simultaneity, and then a corresponding equivalent circuit model is obtained. An equivalent circuit model representing the electrical characteristics of the input end of the THzQCL is built, and an equivalent circuit model representing the optical power characteristics of the output end of the THzQCL is built. Finally, a circuit macro-model is built and comprises an electrical port and an optical power output port, and photoelectric property simulation and temperature property testing are carried out based on the circuit macro-model. The method can test the influence of the temperature on all the photoelectric properties of the THzQCL, simulation on the photoelectric properties of the THzQCL can be achieved, simulation speed and efficiency is improved, and the need for achieving photoelectric mixing simulation on photoelectric devices in actual optoelectronic integrated circuit design and application can be met.

The invention discloses an ultraviolet fixed star and earth simulator. The ultraviolet fixed star and earth simulator comprises a fixed star simulator body and an ultraviolet earth simulator body. The fixed star simulator body is used for simulating a constellation image from infinity, and the earth simulator body is used for simulating an ultraviolet earth image from infinity. The ultraviolet fixed star and earth simulator is installed on an ultraviolet navigation sensor through a vertical type adjusting mechanism, and the constellation image and the ultraviolet earth image are overlapped and recognized by the ultraviolet navigation sensor at the same time.

The invention relates to a radar simulation method, a radar simulation device, a storage medium and electronic equipment. The method comprises the following steps that: a simulation camera is set according to the position of a simulation radar in a three-dimensional simulation scene, and the viewport of the simulation camera can intersect with all simulation radar rays of the simulation radar; thepoint cloud data of the three-dimensional simulation scene are acquired according to the simulation camera; corresponding plane pixel coordinates of the simulated radar rays in the simulated camera are acquired; and sampling is performed in the point cloud data according to the plane pixel coordinates, and point cloud data obtained by the sampling are taken as the simulation result of the simulation radar. By means of the above technical scheme, the simulation camera can be arranged to assist the simulation radar in simulation, and therefore, the simulation speed of the radar is increased toa great extent, the expansibility of the radar simulation is improved to a great extent, and multiple radars can be simulated at the same time with simulation speed guaranteed.

The present invention relates to the field of power electronic device modeling, and particularly relates to a modeling method for short time freewheeling reverse recovery of a spike voltage of a power diode. The method comprises: based on the basic structure of a power diode and the operation principles of semiconductor physics and power electronic converter devices, by building a physical model and a behavior model of turn-on and turn-off transient states of the power diode, and through physical mechanism analysis of turn-on and turn-off transient states of the power diode, obtaining a relationship between key parameters of the two models, so as to establish a modeling method of a hybrid model based on the physical model and the behavior model; and based on the hybrid model of the turn-on and turn-off transient states of the power diode, establishing a model of reversely recovering a spike voltage under a short time freewheeling condition. The method provided by the present invention can not only ensure model accuracy but also reduce model complexity.