A Research On The Iterative Calculation Of 3-D Electric Field Of Composite Insulator With The FEM-BEM

Insulators are widely used by power utilities. The advantages of composite insulators, especially the advantages of pollution performance, low weight and high mechanical strength are prominently featured. However, with more and more composite insulators used in service, there emerged many problems. It is very important to study fully the performance of composite insulators. Having summarized the calculation methods of electric field, this paper selects the combination of FEM and BEM according to the features of composite insulator. In light of fact that both FEM and BEM have different characters and they are complementary to each other, an iterative method is developed by combining the two methods using domain decomposition method, which combines the merits of both and keeps each other's individuality.FEM makes use of the ANSYS-Emag software, while BEM adopts our own developed program. A basic form of the iterative calculation with the combination of FEM and BEM is put forth. We analyzed the effect of such factors as grids size, boundary shape of region, and relaxation factor on the convergence of this iterative calculation by calculating two-dimensional iterative calculation examples. We take its conclusions as the three-dimensional iterative calculation's references. At the end, we confirmed the feasibility and veracity of this iterative calculation method by resolving a three-dimension calculation example of 220kV line composite insulator.