Stability characteristics of fully superconducting and damperless generator with excitation control in fault condition

A fully superconducting generator, which possesses both superconducting armature windings and superconducting field windings, has great potential merits to increase efficiency and decrease size and weight, compared with a partially superconducting generator that has normal armature windings and superconducting field windings. To obtain these merits, the warm and cold dampers should be omitted. However, omission of these dampers deteriorates the stability of the generator operation. In this paper, the authors present a simulation of a fully superconducting and damperless generator (FSDG) behaviour under fault conditions. Knowledge of behaviour under fault conditions is important for design of the superconducting windings of the FSDG. They show a possibility that the superconducting windings, both the armature and field, are quenched in a short circuit fault condition. They also show that excitation control allows the FSDG to stably recover from fault conditions, if the windings are not quenched, and that the current limiting devices to prevent the windings from quenches caused by a fault is necessary for a practical FSDG.<>