An Estimation Method for Real-Time Thermal Capacity of Traction Transformers Under Unbalanced Loads

Real-time thermal capacity estimation is not only part of prognostics and health management but also determines the dynamic loading capability traction transformer. The hot-spot temperature (HST) vital parameter for real-time estimation. In high-speed railway, unbalanced loads two phases transformer cause winding losses therefore affect top-oil further influence HST in each phase. order to explore performance under load (current), a model calculating was proposed incorporating interaction between power supply phases. This treats loss phase independently, considering dependence ohmic eddy current losses. A circuit topology presented with independent windings sharing same temperature, where an improved heat transfer correlation used account nonlinear convection. verified by factory rise tests field operation data batch transformers.