The present work proposes the design process of a novel dual-core electromagnetic energy harvester (EMEH) for the use in a deicing robot, used on power transmission lines. The EMEH is designed with a dual-core where Silicon (Si) and Nickel (Ni) steels have been used in order to take advantage of both materials characteristics. An analytical model for the EMEH has been proposed in this paper which is compared with the 3D finite element method (FEM) based model of the EMEH under the same design specification. Moreover, considering the magnetic equivalent circuit model of the EMEH, equivalent circuit parameters are determined. Furthermore, to obtain the impedance matching and to extract the maximum real power from the EMEH, power optimization circuit consisting of a capacitor and a buck-boost converter is proposed and the parameters for the power optimization circuit are evaluated. To validate the effectiveness of the EMEH and its power optimization circuit, a co-simulation design platform is developed using the 3D-FEM and MATLAB coupled in a python-based environment. On the co-simulation platform, the charging of a rechargeable battery of 15 V is verified.