A New Methodology for Power Transformers Factory Drying Process Control

One of the most important phenomenon that increase the ageing of power transformers is the moisture accumulation in their oil-paper insulation system. The factory drying process of power transformers is made with the objective to reduce the moisture content present in the cellulosic insulation through the heat addition and control of variables as temperature and environmental humidity. However this kind of control implies to have an efficient method to establish the optimal drying times. In this work, a new methodology that considers the use of a coil's scale model to emulate the power transformer winding behavior using FDS measurement is described and a validation case is analyzed to assess the main properties of this proposal.