Modeling and analysis of three phase induction motor with broken rotor bar

Owing to their extensive use and waste presence in different procedures and processes, induction machines are rightly called as the work horses of the industry. Adequate and timely maintenance, fault finding and repair of these machines is a mandatory requirement for efficient working. In literature, extensive work has been presented exploring induction machine faults their symptoms and remedies. Broken rotor bar is one of the highly investigated. Due to the complexity involved in observing this fault, indirect methods to detect its presence are employed. Simulation is a modern tool to analyze machines under different operating conditions. However, in case of a faulty machine, model becomes different as compares to the normal mode. In this paper a three phase induction machine model is presented having broken rotor bars. Moreover, comparative analysis is performed between faulty and healthy case. An easy to comprehend model of an induction motor in abc frame is described to understand the parametric change of a faulty model of an induction motor. The implementation of both healthy and faulty model is done using Matlab/Simulink software. First, the healthy motor is simulated and then the results of faulty motor are compared with the healthy motor to understand the change in response of faulty and healthy motor. Consideration is on broken rotor bar fault but other faults like bearing fault, phase imbalance and mechanical faults can also occur because of broken rotor bar. As the motor is the backbone of the process of an industry a short time shut down of a plant is avoided, the method proposed can be helpful in understanding the current and frequency response of an induction motor which can be use to avoid breakdown maintenance.