Study of the Operating State of a Synchronous Motor Electric Drive by Means of Changes Estimation of the Stator Current Behavior

Abstract

The article proposes a model for the research of the changes in the operating state of a three-phase synchronous motor used in an electric drive of the technological mechanisms. The model has been implemented in the MATLAB software environment based on the Park-Gorev equations, which has found wide application in Electromechanics. It has become possible to estimate during transient changes in the electromagnetic torque of the electric motor along the axes d and q, and stator currents in phases a, b, c, as well as the changes in the ratios of the currents of the reverse and direct sequence. It is confirmed that when the supply voltage of the network and the load torque of the technological mechanism change, in the stator phase windings, currents of the reverse sequence appear. For the considered electric drive motor, the reverse sequence current does not exceed 1.5% of the direct sequence currents, meanwhile the permissible limit according to the standard is 8%. The research model of the operating state of the synchronous motor can be successfully used to identify the pre-emergency state of the operated electric drive systems, assess the causes of their occurrence, and make optimal decisions. The obtained results can also be successfully used for intelligent diagnostics in order to develop automated control systems.