Research on Temperature Rise in Stator Transposition Bar in a Turbine Generator Based on a Coupled Loss Temperature Thermal Network Method

The present paper addresses a problem that many traditional analytical calculation methods ignore the coupling relationship between loss and temperature rise. In this paper, a 51.51 MW turbine generator is taken as the research object, and a transient thermal network method coupled with loss and temperature rise for calculating the temperature rise in a stator transposition bar is proposed. Considering the influence of temperature change on the AC loss of strands, a thermal network model coupled with loss and temperature rise is established to complete the calculation of thermal conductivity matrix parameters. A sparse matrix storage method is proposed to reduce the memory usage of the high-order matrix. The linear iterative method is introduced to accelerate the solution of the equation. The Newton Krylov method is used to handle the coupling between loss and temperature rise. In this way, the transient temperature rise in the stator transposition bar is calculated rapidly. The accuracy of the thermal network model coupled with loss and temperature rise is verified by comparing its results with the three-dimensional simulations. Finally, a new combined transposition structure is proposed to suppress the temperature rise in the stator transposition bar.