The Numeral Simulation And The Model Of The Electromagnetic Field In The Electric Eddy-Current Detection For The Cable Eccentricity

During the production process of the cable, the biased cable is one of the main factors to affect the cable's quality. The product's quality has a direction effect on the reliability of some other products, the safety of equipments, as well as the development of all the industry and society. Thus the producers and the product users pay much attention to this product's quality highly. The electric eddy-current detection is one of the proved effective methods and no loss detection, which is an important use of eddy-current effect. However, recent years the study of electric eddy-current detection mostly overweights the study of measuring system, and the design of the eddy-current.Methods are still equivalent magnetic circuit and equivalent electric circuit model calculation and experiment's experience design method. These methods have many problems to the design and numerical number analogy of electric wire. Electric potential and electric eddy-current detector, such as the wire size, the wire core type (solid core or twisted line),the wire core conductivity, the magnetic permittivity and the optimize match of the detector's form, aren't made an incisive analysis. So it is necessary to reflect the inner reality physical field's numerical number analogy method to analysis and improve the magnetic field and the computing accuracy of the cable's eddy-current detection.ï¼´his affords helping for the researching of biased cable instrument in the future.First open domain electric magnetic problem's breaking method is done with, which supposing fictitious boundary far away from the region. Second breaking the infinite region into the finite region and supposing the electric magnetic is too small to be ignored. Thirdsupposing the magnetic field value at the edge of is zero and this region use relatively mature method of A, A- merged into Coulomb's law to set up mathematical model.The position of the imaginable boundary can be get by calculating the fictitious boundary in the different positions and 2-D wire core eddy current loss's convergence.To obtain the high accuracy as well as little calculation, IC-CBCG method is applied to solve the finite element equation system of 3-D eddy-current field. Finally distribution of 3-D eddy-current field and Variation curve of eddy current loss to the variation of wire position can be get.The computing results show this method increases calculates quantity, although it prolonged calculate time comparing with other methods. Therefore, simplified calculate is easy to be understudied and mastered.