BASIS FOR NONDESTRUCTIVE INDUCTION CONTROL OF WINDING INSULATION OF ELECTRICAL MACHINES

The relevance of the work is caused by the fact that electric machines are used in most production processes of various industries. The failure of the electrical machine leads to a crash, shutdown and consequently to high economic cost to elimination of the results of machine failure. The results of electric machines failure is especially tangible in exploration, production and transportation of geo-resources in oil, mining, coal, chemical and other industries, as these industries are the basis of budget formation now. The reliability and safety of these machines depend on condition of winding insulation, i.e. the enamel insulation of winding wires. Thus improving control of the enamel insulation of winding wires, their quality is the critical issue. The aim of the research is to study the possibility of using electromagnetic induction for non-destructive testing of enamel insulation of winding wires. Research methods: electromagnetic, for generating and studying the characteristics of a signal of contact defects transducer; micrometer, to determine the geometrical sizes of defects in enamel insulation and to match them with the control results. Results. The authors have studied the possibility of using contact sensors of defects for controlling insulation of winding wires when using the induced EMF as a signal in the controlled wire conductor. The authors developed the method of controlling the defects in enamel insulation of wires to determine the number and length of defective areas of wire moving with any variable speed in it. The scheme of defects meter was proposed and the principle of its work was considered. The authors identified the systematic error when controlling the defects length caused by the finite size of the defect sensor. The paper introduces the method of its elimination.