Assessment of Electrical Machines’ State Based on Mathematical Modeling of Defect Formation in Windings

The highest quality and timely diagnostics of windings’ state of various types of electrical machines including of asynchronous motors’ windings is an impoitant task. Among the existing diagnostic methods currently the most promising are those ones based on methods for analyzing resonance processes occurring in electrical machines. The aim of the article was to assess the possibility of use resonant processes occurring in electrical machines for qualitative diagnostics of their windings state using the asynchronous motors example, to build mathematical models that allow describing defect formation in windings and to analyze the deviation of mathematical models relative to the results obtained.Analysis of the influence of the level of interturn resistances, the number of closed turns and the location of closed turns in sections on the phase-frequency characteristics of asynchronous motors windings of various classes has been carried out. Mathematical models of the phase-frequency characteristics are obtained, coefficients of polynomials are determined and the relative discrepancy between these mathematical dependences relative to the experimental data is estimated depending on the considered parameters characterizing defects in the coils’ windings of electrical machines.Obtained mathematical models and coefficients for them can serve as the basis for construction of automated control and diagnostic systems for checking of the windings state of electrical machines including assessing the residual life of their work.