Hybrid Sensor for Determining Air Gap Anomalies in Synchronous Generators

In the paper shows, that from the moment of the start of production until the moment of final decommissioning, a number of physico-chemical and thermomechanical processes take place in the structural elements of powerful hydrogen generators (HG) in its rotating and non-rotating structural elements. Over time, these processes lead to a change in the actual technical condition of the HG nodes and the development of defects that affect the efficiency of the HG. The determination of the actual technical condition of HG based on the evaluation of a complex of control and diagnostic parameters of various nature, which include electrical, mechanical, temperature, magnetic, and technological parameters. The reliability of determining the actual technical condition, determining the presence of defects in the facility, assessing the possibility of further use of the energy facility depends on how fully the controlled parameters reflect its actual technical condition. The air gap between the rotor and the stator is one of the main nodes of the HG, in which the mechanical energy of the water pressure transformed into electrical energy. The design feature of the air gap in the HG is its relatively small size compared to the bore diameter of the stator. The size and value of the asymmetry and uneven distribution of the air gap largely determine the actual characteristics of the HG and its behavior during operation, and significantly affect a number of other characteristics of the machine (Value of the end magnetic fluxes and losses that occur in the extreme packages of the core and pressure plates of the stator; on the value and distribution of losses on the surface of the rotor poles; as well as on the area of permissible modes of operation of the generators). Determining the value of asymmetry and uneven distribution of the air gap only based on the data of the air gap control does not allow to fully determining the type of defect that led to the change in the air gap distribution on a working machine. For increase the efficiency of determining the types of defects associated with air gap anomalies, it is advisable to use hybrid sensors, which, in addition to capacitive air gap sensors, contain an additional sensor in their structure was shown.The calculation of the additional information component in the form of EMF is given.