Imitation Modeling of an Inter-Turn Short Circuit of an Asynchronous Motor Stator Winding for Diagnostics of Auxiliary Electric Drives of Transport Infrastructure

Abstract

A scientific approach to calculating the parameters and characteristics of an asynchronous motor in the inter-turn short circuit mode in one phase of the stator is proposed to create the foundations of a diagnostic complex for assessing the condition of asynchronous motors of the transport infrastructure. This approach consists of the fact that in the model with which the research is carried out, it is proposed to take into account changes in the mutual inductance of the motor when the AC impedance of one of the stator phases changes. Using a new approach to modeling processes occurring in an asynchronous motor during the inter-turn short circuit in one phase of the stator, pulsations of the torque on the motor shaft were studied for different values of the AC impedance and resistance of one of the stator winding phases, which corresponds to varying degrees of the inter-turn short circuits.

Determining an additional diagnostic parameter for improving the accuracy of assessment of the condition of stator windings in an induction motor

“…Preliminary analysis of the effect of simultaneous inter-turn short circuit in two phases on mechanical and operating characteristics [5] revealed that the type of dependences is similar to that of inter-turn short circuit in one phase [4]. In addition, based on the reported studies in work [5], it was established that for the construction of a system of built-in diagnostics, with accurate identification of the type and nature of the resulting defect of the stator winding, the available diagnostic parameters are not enough.…”

“…In works [4,5], it is shown that it is most expedient for further studies of the influence of inter-turn short circuit simultaneously in several phases of stator winding on the characteristics of an induction motor to apply the mathematical model given in paper [24]. The proposed simulation model of an induction motor with a squirrel-cage rotor is made in "braked coordinates" and implemented in the MAT-LAB (USA) programming environment.…”

“…To determine the change in the mutual inductances of the windings, the effect that the change in the complex resistance of one winding (several windings) has on the inductance of the magnetic circuit according to the algorithm presented in work [25] was determined. In works [4,5], that algorithm is implemented for the study of inter-turn short circuits in the stator winding at one and simultaneously in two phases.…”

“…During the operation of the transport, various kinds of malfunctions occur, causing a sudden failure of the engine or a deviation of its parameters from the rated values. When a series of parameters fail to meet the established boundaries, it causes an increase in energy losses in the engine [2,3] and, as a result, a deterioration in its performance characteristics and parameters [4,5].…”

“…With this defect, given a small number of squirrel-closed turns of the damaged phase of the winding, the induction motor may stay in working condition. At the same time, the value of the current in the damaged phase increases, the power consumed from the network increases, the efficiency and power factors decrease [4,5]. With a further increase in the number of squirrel-closed turns in the winding phase, the electric motor enters an inoperable state due to the critically increased value of the phase current in the damaged phase [6].…”