STABILITY CHARACTERISTICS OF FULLY SUPERCONDUCTING AND DAMPERLESS GENERATOR WITH EXCITATION CONTROL IN FAULT CONDITION

A fully superconducting generator, which possesses both superconductin g armature windings and superconducting field windings, has great pote ntial merits to increase efficiency and decrease size and weight, comp ared with a partially superconducting generator that has normal armatu re windings and superconducting field windings. To obtain these merits , the warm and cold dampers should be omitted, However, omission of th ese 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 controll ing the operation, excitation voltage of the field windings, and showe d that a FSDG connected to an infinite bus could be stabilized, In thi s paper, as an extension of our previous study, we present a simulatio n of FSDG behaviors in fault conditions. Knowledge of the behaviors in fault conditions is important for design of the superconducting windi ngs of the FSDG, We show a possibility that the superconducting windin gs, both the armature and field, are quenched in a short circuit fault condition, We also show that the excitation control allows the FSDG t o stably recover from fault conditions, if the windings are not quench ed, and that the current limiting devices to prevent the windings from -quenches caused by a fault is necessary for a practical FSDG.