Off-line coupled simulation method for transformer performance assessment under DC bias condition

In this short communication, we intend to introduce an off-line coupled simulation method (OCM) framework for the DC biased power transformer performance assessing. The OCM combined with the electromagnetic transient (EMT) and finite element method (FEM) simulation, which can benefit from fast calculating excitng current and deail representing the transformer's internal performance. It can be concluded from the numerical results of single-phase and three-phase transformers that it's feasible to estimate the transformer performance under DC bias condition with the proposed OCM framework, and it's quite promising in engineering application.