Stability characteristics of fully superconducting and damperless generator connected to power grid

The damperless fully superconducting generator can more efficiently use the magnetic flux produced by the field windings and be more compact and have a rotor of simpler structure than a partially superconducting generator, because both the field and armature windings can be placed in the same cryogenic region and the gap between the windings can be minimized. However, a damperless machine causes a dynamic instability problem when interconnected to an electric power system, and a device to stabilize the system is required. The authors propose a method to stabilize the operation of the generator by controlling the excitation voltage of the field winding. Details of the method are explained. Its effectiveness is shown by numerical simulation.<>