Estimation of the turn-to-turn short circuit effect on the induction motor operation quality
The paper is devoted to the evaluation of the influence level of turn-to-turn short circuit in one of rotor phases on induction motor operation quality. The object of research is an induction motor with a phase rotor widely used as a drive mechanism in the cement industry characterized by severe operating conditions. Because of the turn-to-turn short circuit mode specificity, application of a standard method for calculating motor characteristics is impossible in this case. A modification of the classic mathematical model for calculating currents and torques under rotor circuit unbalanced condition is presented as a solution of the problem. As a result of numerical simulation, the dependences of phase currents of the stator and rotor windings, the angular frequency of the rotor, as well as static mechanical characteristics of the machine in the turn-to-turn short circuit mode in one of the rotor phases are shown.Based on the results obtained, criteria are pointed out that make it possible to conclude that it is advisable to continue the damaged motor operation. As future research, it is possible to create a real-time diagnostic system based on the developed algorithm for calculating symmetric modes of an induction motor.