5 results about "Transient field" patented technology

The invention discloses a three-phase transformer single-phase grounding short circuit leakage magnetic field simulation analysis method based on a combination of three single-phase transformers, and aims to solve the problem that leakage magnetic field distribution and electromagnetic force conditions of a three-phase transformer formed by the combination of the three single-phase transformers cannot be accurately simulated when a single-phase grounding short circuit fault occurs in the prior art. Constructing a three-dimensional finite element geometric model of the single-phase transformer according to parameters such as the actual size of the transformer; then importing ansys Maxwell software, and adjusting the position to generate a three-dimensional calculation model; setting material attributes of each field domain, creating a winding, and constructing an external circuit matched with different working conditions; then setting a solution domain and boundary conditions, carrying out reasonable mesh generation, and selecting a transient field for simulation solution; and finally, checking simulation results such as short-circuit current and magnetic flux leakage nephograms. The method can accurately analyze the single-phase grounding short circuit fault of the transformer, accurately simulate the fault condition, find hidden dangers in advance, and provide reliable support for fault prevention and scientific design.

The invention discloses a method and equipment for calculating a correlation coefficient of an S-FDTD transient field, and belongs to the technical field of radio wave propagation calculation, when the S-FDTD method based on Taylor expansion is adopted to solve a transient field problem, the correlation coefficient in the S-FDTD method is pre-estimated based on an NIPC method, so that the S-FDTD method can be used for high-precision simulation of transient field random performance. Results show that the method can obtain a proper correlation coefficient at a low cost, compared with a 5000-time Monte Carlo method, the calculation sample number of the method is about five thousandths, meanwhile, when the S-FDTD method is used for steady-state field simulation, the method can also be expanded and applied to a steady-state field, the S-FDTD method does not need to wait for the field to enter a steady state, and the time consumption is less than that of MC-CC.

The application provides a transformer optimization design method and device based on a combined simulation strategy, and belongs to the field of power electronics. The method provided by the application comprises the following steps: establishing a three-dimensional simple geometric model of a transformer; obtaining an excitation waveform reflecting the actual working state of the transformer; performing first eddy current field simulation on the three-dimensional simple geometric model, importing the generated adaptive grid into a transient field, applying the excitation waveform to carry out transient magnetic field simulation, adjusting the cross-sectional area of a magnetic core or the number of turns of a winding according to the magnetic flux density distribution, and determining the structure of the magnetic core; establishing a two-dimensional cross-sectional model of a winding stack based on the confirmed magnetic core structure, performing two-dimensional magnetic field simulation, comparing the loss and current density trends, and screening the optimal winding configuration; combining the confirmed magnetic core and the optimal winding to construct a three-dimensional fine model, obtaining a first grid through second eddy current field simulation, and importing the first grid into a transient field to complete final performance verification. The method and device provided by the application can improve the simulation efficiency and design accuracy, and shorten the development cycle.

This invention discloses a rapid calculation method for equivalent circuit parameters of a high-capacity AC excitation motor, belonging to the field of motor parameter calculation. Starting from the motor's magnetic flux path and characteristics, this method divides the stator and rotor leakage inductance into stator and rotor slot leakage inductance, stator and rotor harmonic leakage inductance, stator and rotor end leakage inductance, and stator and rotor tooth tip leakage inductance. For each magnetic flux path, the four parts of leakage inductance are calculated precisely. It fully utilizes information such as flux linkage and magnetic energy storage obtained from static field simulations to calculate motor parameters. Only three static field simulations are needed to calculate all motor parameters. Compared to conventional parameter calculation methods based on transient fields, this method improves the parameter calculation efficiency for this type of motor and helps shorten the design cycle of high-capacity AC excitation motors.

The invention relates to a transient electromagnetic field-circuit coupling high-precision calculation method based on an A-alpha formula, and the method comprises the steps: dividing grid data into a plurality of polyhedral smooth regions with corresponding edges as centers according to the edges in the grid data of a three-dimensional motor 1 / 8 periodic model; a smooth vector shape function of edges and a smooth shape function of nodes in the polyhedron smooth domain are calculated; constructing a transient field-circuit coupling equation set based on an A-alpha formula, transient eddy current and coulomb specifications, and rewriting the transient field-circuit coupling equation set according to the smooth vector shape function of each edge, the smooth shape function of each node and a Galerkin method to obtain a transient field-circuit coupling system equation; further rewriting the transient field-circuit coupled system equation into a Newton iteration linear equation; and iteratively solving the Newton iteration linear equation by adopting a Newton iteration method until the Newton iteration linear equation converges to obtain a magnetic vector bit in field-circuit coupling, thereby realizing high-precision numerical solution of the transient field-circuit coupling problem in the complex motor system.