Power plants typically use generator step-up (GSU) transformers, station service/auxiliary transformers, and unit auxiliary transformers in switchyards. The GSU increases generator output (e.g. 13-24 kV) to transmission voltages (110-400 kV), enabling efficient bulk power transfer. Auxiliary transformers supply plant loads such as pumps, fans, and control systems. These units must withstand high fault currents, thermal cycling, and fast switching events common in plant operation.