Stabilization of a fully superconducting, damperless generator by excitation control

Abstract The development of ultrafine filaments superconductors for 50/60 Hz makes possible a fully superconducting generator which has superconducting field windings and armature windings. By omitting dampers and narrowing gaps between the field and the armature windings, the size and the weight of the fully superconducting generator can be drastically decreased. However, the damperless generator is inherently unstable and thus must be stablized by an appropriate method. We have investigated a method of stabilizing the generator in which the excitation voltage of the field winding is controlled by the state value feedback technique. The state values of the system are estimated by a state‐value observer and the feedback constants are determined according to optimal control theory. It is shown that this method is effective in stabilizing a fully superconducting, damperless generator.