Effects of induction motor end ring faults on motor performance. Experimental results

Abstract

Induction motors are inherently robust in construction, although faults can occur inside or outside in the motor due to various reasons. These failures cause deterioration of the motor performance and it can even cause the motor to be disabled. As a result of literature studies, it has been seen that a hole is opened in the middle part of the rotor bars for the induction motor rotor bar failures. In this study, different the studies in the literature, faults were introduced on the end ring part and on the intersections of the end ring and the rotor bars. The aim of this paper, end ring faults was investigated the effect of a squirrel cage induction motor on the motor performance. Seven motors with the same power and physical characteristics were used in the study. One of the motors is used as a reference (healthy) motor and the other six motors which have got with various faults in the end ring part. The three motors were used exactly as the faulty motor at the intersection of the end ring and the rotor bars, and the other three as the faulty motor which caused a scraped on the end ring part. No-load, locked-rotor and loaded operation tests were performed separately for each motor. The core losses, copper losses, current, power factor, efficiency, torque-speed characteristic and etc. values were obtained for seven motors. The motors that are tested are squirrel cage, 3 phase and 4 kW power. The obtained results are presented in comparative tables and graphs. Core loss and copper losses have increased by 21.57% for 3 scrapped motor and 9.83% for 2 broken rotor bar motor respectively, compared to the healthy motor. The efficiency value is reduced by 3.4% for the 3 scraped motor.