The development of computer-based defect characterization scheme for magnetic flux leakage (MFL) method require adequate mathematical models to describe the complicated interactions sources, fields, velocity and defects in materials. In this paper, a 3-D transient finite element model based on T-Omega formulation was used analyse MFL system at high velocity, with regard eddy currents induced steel tube because relative movement between exciters specimen. change profile electromagnetic field,...

Crustal movement and land subsidence will cause tower foundation settlement, which seriously affects the safety of transmission line operation. This paper proposed a short-term failure warning method for under condition based on finite element method, strain monitoring time series prediction. By simulating stress distribution in actual weak components settlement were founded. Combined with simulation results various conditions, reliability is verified, variation range corresponding measuring...

We present fundamentals and procedures of a composite grid method (CGM) for determining eddy currents in moving conductors. Based on the finite-element (FEM), CGM uses two separate mesh grids - one coarse fine to calculate global region local separately. The results are interpolated onto boundary as its Dirichlet's condition. Then equations solved order obtain reaction force boundary, which is reacted modify right-hand-side load vector. And re-solved. iteration continues until converge....

As an important indicator of the electromagnetic environment UHVDC transmission lines, ion flow field needs to be quickly calculated and updated in case meet requirement building a digital twin power system. This paper is based on UFEM starts from two aspects: electric intensity convergence charge density convergence. a) An adaptive iteration factor for update introduced, which can automatically control speed according change degree intensity, ensuring rapid stable density. b) On this basis,...

A composite grid method (CGM) was applied in the analysis of eddy current field involving movement. The region source and air including background moving conductor discretized with a global grid. local trouble remeshing normal finite element technique based on one set is overcome CGM. At each time step, instead mesh regeneration it only necessary to change coordinates nodes. fields two sets grids are solved independently by related an interpolation matrix. dynamic characteristics 3-D coil...

Few-shot Semantic Segmentation(FSS)aim to adapt a pre-trained model new classes with as few single labeled training sample per class. The existing prototypical work used in natural image scenarios biasedly focus on capturing foreground's discrimination while employing simplistic representation for background, grounded the inherent observation separation between foreground and background. However, this paradigm is not applicable medical images where background share numerous visual features,...

Transmission tower is an important component of power system, and heavy iced transmission line has became one the factors against its safety stability in China's system these years but designed from traditional standard can't endure more worse environment. In this paper, for positioning weak points under icing accurately providing accurate positional parameters to online monitoring devices, strain section model built analysis their mechanical properties wind conditions .In proposed method,...

In recent years, the global climate has changed significantly, extreme weather increased, and lightning activities have become more frequent intense. How to predict activity in area covered by transmission line is key achieve effective protection power grid. Firstly, a nonlinear correlation model between meteorological information including temperature, precipitation, atmospheric pressure, wind direction, speed humidity attributes was established based on Bayesian network. Then quantitative...

A novel method, which is based on electromagnetic field theory to calculate the current distribution in grounding grid presented this paper. The finite element method (FEM) used of fault grids. By using both unidimensional units and three-dimensional modeling its surrounding soil, performance real substation can be analyzed. grids as well soil seen clearly. accuracy calculation improved significantly flowing leakage distributed easily obtained under different condition. 1. Introduction...

A novel method, which is based on electromagnetic field theory, to calculate the current distribution in grounding grid presented this paper. The finite element method (FEM) used of fault grids. By using both unidimensional units and three-dimensional modeling its surrounding soil, performance real substation can be analyzed. grids as well soil seen clearly. accuracy calculation improved a lot flowing leakage distributed easily obtained under different condition.

Automatic segmentation of the line-like regions plays a very important role in automatic recognition system, such as cracks X-ray images, vessels CT images. In order to automatically segment X-ray/CT this paper presents robust line filter based on local gray level variation and multiscale analysis. The proposed makes usage its enhance image, which can well overcome problems image noises non-uniform intensity For detecting various sizes regions, an pyramid is constructed different neighboring...

Based on analyzing the mathematical model of Brushless DC Motor (BLDCM) and key researching electric process state spaces BLDCM main module, taking its one space as an example, system is proposed a new method simulation model. This establish dynamic model, made to verify theoretical Experimental results demonstrate successfully applied design vehicle drive simulation.

In recent years, a prominent issue has emerged due to the rapid development of power system: short-circuit currents often surpass block capacity breakers. This paper summarizes current limiting measures (CLMs) in AC systems, including topology-based and equipment-based measures. The principles different their advantages disadvantages are analyzed. A comparison terms difficulty implementation, effectiveness limiting, economics, impact on system stability is carried out. results indicate...

When the traditional tower circle method is used to calculate lightning parameters of transmission lines, because radius far greater than span, there will be many overlapping areas. The in overlap areas calculated times, it not only increase calculation amount, but also lead inaccurate results. In this paper, a new statistical for lines proposed. line corridors are divided into block rectangles equal size, which close each other as much possible reduce impact overlap. Taking 500kV Xianmeng I...