Dynamic Thermal Network Modeling for Disk-Type Winding Domain of On-Board Traction Transformer

For the on-board traction transformer (OBTT), due to its compact structure and continuous motion environment, in the period of design and maintenance, dynamic thermal characteristics were getting more attention. In this study, a dynamic thermal network model was proposed for the winding domain inside OBTT, where distributed thermal capacitance was introduced to reflect the heat storage process. The thermal resistance of stagnant oil was first modeled for the heat transfer occurring near boundary layers. Based on the real disk-type winding geometry from one 6.3-MVA OBTT, the proposed model was verified with the computational fluid dynamics (CFD) transient simulation and temperature-rise test. Then, the dynamic thermal characteristics could be easily obtained with the proposed model. The proposed model can be used for design optimization and the basis for dynamic thermal rating.

Automated summary

A dynamic thermal network model was proposed for the winding domain inside OBTT, which introduced distributed thermal capacitance to reflect heat storage. The thermal resistance of stagnant oil was first modeled to describe heat transfer near boundary layers. The proposed model was validated with CFD simulation and temperature-rise test, based on a real disk-type winding geometry from a 6.3-MVA OBTT. The model can be used for design optimization and dynamic thermal rating.