Vertical hydraulic generators experience with dynamic air gap monitoring

Dynamic air gap monitoring is the process of measuring the rotor-to-stator distance of a salient pole hydroelectric generator while it is in any of its operating modes. The main purposes for using dynamic air gap monitoring are to assist in minimizing loss of revenue through preventing the loss of rotor-to-stator air gap, and to aid in the maintenance and maintenance scheduling of large hydroelectric generators. The authors discuss the air gap measuring principle, the technique, and the equipment used. They also include several case studies in which dynamic air gap measurement data was analyzed and correlated to generator performance