Impact of Shielding Configurations With Magnetic-Electrically Conductive Alloy on Multi-Physical Fields in the End Region of Air-Cooled Synchronous Condenser

In large-capacity air-cooled synchronous condensers (ACSCs) operating under deep leading-phase conditions, significant end leakage flux induces substantial losses and heating in the stator end components. Effective electromagnetic shielding is therefore a critical design consideration and a novel shielding configuration utilizing magnetic-electrical conductive alloys is proposed in this article. Using a 300 MVar ACSC as a case study, the three-dimensional transient electromagnetic field model of the end region is first established. The effects of four configurations (copper shield+magnetic shield, Fe-16%Cu alloy shield+magnetic shield, single Fe-20%Cu alloy shield, and single magnetic shield) on the leakage flux density and losses in end components are analyzed. Subsequently, a global ventilation network and a fluid-thermal coupling model for the end region are developed for each configuration. The results from network and aforementioned losses serve as boundary conditions for the fluid-thermal coupling model. The flow fields and the temperature distributions under different configurations are then determined. The findings demonstrate that each shielding configuration exhibits specific advantages and limitations. Experimental validation based on traditional scheme confirms the accuracy of the model and methodology. The simulation results elucidate the significant potential of the Fe-Cu alloy. The single Fe-20%Cu configuration reduces the hot-spot temperature of shield, and significantly lowers weight and cost while effectively protecting the end iron core.