Analysis of Electromagnetic Field and Heat Transfer in the End Region of Variable-Speed Pumped Storage Generator-Motor at Different Speeds

Large variable-speed pumped storage generator-motors (VSPSGMs) offer superior speed adaptability and rapid adjustment capabilities for both active and reactive power. However, their rotor AC excitation systems pose significant challenges for electromagnetic design and ventilation cooling due to variable operational conditions. In this paper, the electromagnetic parameters, ventilation cooling system and heat transfer mechanism of 10 MW VSPSGM are studied. Losses in end components of VSPSGM are obtained at different locations. Fluid velocity distributions are analysed under different speeds. A coupled fluid-thermal model is developed for the end region of the 10 MW VSPSGM. Complex fluid flow and temperature distribution of end components in the VSPSGM are studied and compared at different speeds. The location of the highest temperature point is obtained. The calculated results are compared with the experimental test values. The ventilation cooling system design and accuracy of the calculation method are verified.