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 a previous work, we have proposed a method to stabilize the operation of a fully superconducting and damperless generator (FSDG) by controlling the operation, excitation voltage of the field windings, and showed that a FSDG connected to an infinite bus could be stabilized, In this paper, as an extension of our previous study, we present a simulation of FSDG behaviors in fault conditions. Knowledge of the behaviors in fault conditions is important for design of the superconducting windings of the FSDG, We show a possibility that the superconducting windings, both the armature and field, are quenched in a short circuit fault condition, We also show that the 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.