This paper proposes novel techniques for the improvement of the convergence characteristic of step-by-step time integrations in nonlinear transient eddy-current analyses. The proposed methods, which are based on the time-periodic finite-element method and the explicit error correction method, can extract poorly-converged error components corresponding to large time constants of an analyzed system. The correction of the extracted error components accelerates the convergence of transient calculation efficiently. Furthermore, we extend the performance of the proposed methods in nonlinear problems. Some numerical results that verify the effectiveness of the proposed methods are also presented.