Domain decomposition with subdomain pre-processing for finite element modelling of transformers with stranded conductors

Finite element analysis of transformers with stranded conductors can be computationally heavy due to the fine mesh required for winding domains. In this paper, a domain decomposition method with subdomain pre-processing is proposed to overcome with this problem. In order to solve the field-circuit problem with finite element analysis, the winding domain is modelled initially. Next, the reduced matrix system is obtained from the winding domain formulation. The solution of the entire problem is obtained by solving the winding domain formulation and the reduced matrix system separately. The method is tested on a transformer model in no load operation. Accurate solutions are obtained in both frequency and time domains 7-9 times faster than when using brute-force method.