Concerning the Diagnosis of Asymmetric Modes in the Traction Induction Drive of the Electric Locomotive

Abstract

The result of the study is the justification of the possibility of using the Park vector method to diagnose the presence of asymmetric modes in the drive of an electric locomotive with vector control of induction motors. As a result of simulation it is established that at the symmetry of motor stator windings and supply voltages the Park vector hodograph describes the correct circle, while at asynchronous stator winding asymmetry, or supply voltage vector asymmetry the Park vector hodograph describes an ellipse. Moreover, when the stator windings are asymmetric, the angle of inclination of the ellipse is equal to zero, and the angle of ellipticity decreases with an increasing degree of damage to the windings. The asymmetry of the supply voltage system causes a change in both the angle of inclination of the ellipse and the angle of ellipticity. To identify possible asymmetric modes in the stator windings of the traction motor with asymmetry of supply voltages, an algorithm for recalculating the parameters of the Park vector for the conditions of symmetry of supply voltages is proposed. The structure of the system for diagnosing the presence of asymmetric modes in the elements of the traction drive system of an electric locomotive has been developed.