FEATURES OF MODELING OF ELECTROMAGNETIC FIELD OF ELECTRIC MACHINES WHEN MAGNETIC SYSTEM PROPERTIES CHANGE

• Published in: Natsional'nyi Hirnychyi Universytet. Naukovyi Visnyk no. 6; p. 101
• Main Authors: Zagirnyak, M, Prus, V, Kushch, I, Miljavec, D
• Format: Journal Article
• Language: English
• Published: Dnipropetrosk State Higher Educational Institution "National Mining University" 2016
• Subjects: Computer simulation; Damage; Direct current; Electric motors; Electromagnetic fields; Magnetic properties; Maintenance; Mathematical models
• ISSN: 2071-2227; 2223-2362

Determination of particular features of electric machines electromagnetic field modeling when the change of magnetic system properties is caused by the presence of damages of the main types occurring during electric machines long-term operation and repairs. The comparative experimental analysis of changes of the properties of electric machine magnetic systems during their repair and long-term operation is substantiated. Mathematical grounds for influence of magnetic system main faults on electromagnetic field described by Maxwell's equations. Numerical modeling of magnetic field in electric machines with damaged magnetic systems with the finite-element method. The principles of modeling electromagnetic field in electric machines with magnetic system damages characterized by considerable error-free running time and subjected to a number of overhauls have been grounded. As a result, the necessity of the use of models of various types for calculation of electromagnetic field, depending on the presence and localization of the main types of magnetic system damages, has been proved. The adequacy of the proposed approach to modeling core defects of DC motors has been confirmed. The peculiarities of different types of damages in laminated cores and the ways to take them into account while simulating electric machine electromagnetic field are studied. The ways of solving the mentioned task using the finite element method by the example of computation of the change of vibroexcitation forces caused by the electromagnetic nature in direct current machines are developed. The obtained results make it possible to predict the change of an electromagnetic component of vibration and irregularity of torque distribution of DC motor, caused by laminated core defects. There is also a possibility of estimating the rate of laminated core damage influence on the main IM operating characteristics.