Geraskin A. Vibrodiagnostics of rotor’s damages of powerful asynchronous motors on the basis of the field mathematical models.

The object of research: powerful asynchronous short-circuited motors with damaged winding rotor. The purpose of research: the development of scientific-methodological support for systems of vibration condition monitoring and diagnosis of injuries of powerful short-circuited rotor induction motors by the research of electromagnetic vibroexcitant forces in damaged induction motors based on the field mathematical models. Methods of research: solving of problems in the work was carried out using: methods of mathematical modeling, based on a numerical solution of equations of the electromagnetic field of induction motor using finite element method; the method of the theory of electric circuits; methods of spectral analysis of periodic signals. Vibroexcitant electromagnetic forces are calculated via tensor magnetic tension. Theoretical and practical results and innovations: improved field mathematical model of the induction motor with a damaged rotor, which is based on the assumption of conditional property of the rotor, by considering the influence of electric potential difference; a new field mathematical model developed that takes into account the rotation of the damaged rotor relative to stator in time and allows simulate signal of located on the stator vibration acceleration sensor; first developed circuit-field mathematical model for the analysis of electromagnetic vibroexcitant forces and signals of vibration sensors in induction motors at fracture segments short-circuited rings of winding rotor; developed two methods of diagnosing injuries short-circuited winding rotor of induction motors based on changes in their electromagnetic vibration in the appearance of damages; developed scientific- methodological support for the systems of vibration diagnostics; developed the system of rules of diagnostics based on diagnostic signs and coefficients by which is possible with high accuracy to diagnose the type and degree of damage of rotor of induction motors. A subject degree of introduction: results of the dissertation is used in two companies: the JSC "Scientific and Production Enterprise" Smila Electromechanical Plant" and JSC " Ukratomenergobud ", Kiev, and the results of research in learning process and used by the Department of Electrical Engineering NTUU "KPI" in teaching discipline "Noise and vibration of electrical machines" and performance of students of Bachelor and Master's works; Effectiveness of implantation: received considerable scientific and technical effect which is to increase opportunities clearly identify damages of rotors of induction motors; Sphere of use: systems of vibration control and diagnostics short-circuited induction motors of different types in different variants of rotor damage.