Detailed dynamic thermal-hydraulic network model: Application to liquid-immersed power transformers – Part I

The paper presents the concept of temperature calculation in oil-immersed power transformers based on a detailed Thermal-Hydraulic Network Model (THNM). The THNM is deeply rooted in physics, incorporating detailed construction, material properties, and cooling equipment characteristics. Software tools based on a steady-state version of detailed THNM are becoming prevalent as design tools. However, a detailed dynamic THNM has not yet reached that level of technology readiness. Its practical application lies in operational decision-making, grid planning, and investment planning, as well as monitoring, where the detailed dynamic THNM can be used to simulate transformer thermal behavior during grid operation under variable loading conditions.