3-D Thermal Network Model of Stator Transposed Strands for a Hydrogenerator.

The temperature field of stator strands with a transposed structure is challenging to analyze in large machines. In order to deal with this problem, this article presents a three-dimensional thermal network model of stator transposed strands for hydrogenerator. Take a 250-MW hydrogenerator as an example, and a novel thermal network model is established. In the proposed model, the solving domain is discretized according to the real physical structure, the transposition structure of stator strands is taken into account, and the change of heat sources caused by transposed strands is considered. Next, results of the proposed model are compared with those of the traditional thermal network without considering the transposition structure, and the proposed model can better model the real structure of the stator strands. Then, the effect of a different number of ventilation ducts on temperature distribution is discussed. Besides, the calculation results were compared with the finite-element method, and the proposed method took less time to calculate. Finally, the temperature of the stator was measured by the embedded temperature sensor, and the correctness of the calculation results of the proposed model is verified. The novel three-dimensional thermal network model can quickly and accurately calculate the temperature of stator transposed strands. [ABSTRACT FROM AUTHOR]