Welding is used to permanently join two or more metal pieces together and involves melting of the base material. For this reason, various heating sources, such as gas, electric arcs or laser beams are used, each of them requiring reliable and controllable high power supply. In order to achieve substantial energy savings, industries focus on improving the efficiency of power supply in welding processes. This project aimed at assisting design engineers during the entire development process of WPS to optimise the performance and reliability of welding products. Thereby, the project generated a new set of advanced thermal models for improving the design procedure of magnetic components to be employed in WPS. These improved magnetic components are expected to compensate for the high frequency effects that occur in welding processes that make more efficient use of power. More specifically, the project succeeded in developing compact thermal models that are expected to lead to significant reductions in size and weight of units. Based on computational work, these compact models have been accurately parameterised according to geometrical and thermal properties of materials used. In addition, compact models have been parameterised in relevance to convection of heat transfer through components mediums' depending on airflow properties, such as velocity, viscosity and density. Two models were derived that may be used as resistive thermal networks in electrical simulators, such as Simplorer that was used for this projects purposes. The first comprises two temperature nodes and three thermal resistances, while the second includes four sub-models with two to eight temperature nodes and several thermal resistances. Offered in various shapes and winding types, the models may contribute to great reductions in cost, time and effort during design of magnetic components for WPS.