Calculation of No-Load Damper Winding Loss in Synchronous Machines

Pulsations in the air-gap induction due to the slotted stator construction produce pole-face loss. When a damper winding is present the pulsations link the damper bars producing circulating currents causing an additional loss, which is designated by the term ``no-load damper winding loss.´´ The magnitude of this loss is found to vary from practically zero to as much as eight times the pole-face loss, or to as much as half of the total no-load core loss. A method of calculating the no-load damper loss is developed based on theoretical considerations. As far as the writer is aware no theoretical work has been previously published on this subject.