DEFINITION OF A DIAGNOSTIC SIGNAL FOR MONITORING PERMANENT MAGNET SYNCHRONOUS MOTORS
Authors:   Nosov Magnitogorsk State Technical University, Petushkov Mikhail Yu. , Kholodilov Sergey S. ,   Nosov Magnitogorsk State Technical University
Published: February 2024

Relevance Nowadays, it is possible to achieve a significant increase in the technical and economic indicators of enterprises by improving the reliability of electrical and mechanical equipment. In this case, the time between current and overhaul repairs is increased and operating costs and, together with them, material and other resources are significantly reduced. Metallurgical production is the most expensive in terms of electrical consumption and a significant number of electric drives are concentrated there. For more than a hundred years, asynchronous electric machines have occupied key positions in regulated AC electric drives. Along with them, new types of electric machines have been actively developed in recent decades, which structurally in the active part do not contain windings on the rotor, the rotor is asymmetrical in magnetic relation, the stator can have one or two windings. Such machines include synchronous reactive and inductor electromechanical converters. All studies are of a private nature and do not cover the whole class of electric machines as a whole. There are no unified analytical dependencies for electromagnetic torque, active and reactive powers, power factor, methods of engineering calculations of machines, optimization methods, unified approaches to the synthesis of control actions on stator windings, calculation of losses, the peculiarities of synthesis of such machines for specific production mechanisms are not considered, taking into account the nature of load and speed diagrams and modes of operation in an extended range of speeds and load torques. In connection with the above-mentioned, a comprehensive study of permanent magnet synchronous motor (PMSM) is relevant, and there is a need to determine the diagnostic signs of faults both incipient and manifested. Aim of research The article is devoted to the issues of obtaining diagnostic information in the generator mode of PMSM. It is shown that the generator mode is an effective mode for obtaining a diagnostic signal, allowing to fully implement the methods of mathematical analysis of signals, without introducing errors in the form of spectral components from the work of converters. Research methods The methods of theoretical and experimental research were applied in the work. To conduct theoretical studies used software packages Excel and MathCad; software package MatLab for wavelet analysis and Fourier analysis; software package Elcut to develop a computer model and simulation modeling; the basics of wavelet theory. Results The generator mode is an effective mode of obtaining the diagnostic signal, which allows to fully implement the methods of mathematical analysis of signals without introducing errors in the form of spectral components, which inevitably occur during the operation of converters of any type. The use of the generator mode in PMSM diagnostic systems allows obtaining a much cleaner diagnostic signal, which increases the diagnostic accuracy, reduces the number of false diagnoses and minimizes the masking effect. This mode does not require any changes in the structure of the control system, because during the operation of any PMSM, one way or another, when the speed is reduced or stopped, the motors briefly operates in generator mode.