Utilization of Signal Analysis Techniques in Investigation of Rotor Broken Bars and Misalignment Defects on low power Induction Machines

Induction motors are the important constituent of the industrial machinery used in present date, mainly in the field of power generation, goods manufacturing, fuel refineries and other energy sectors. A large number of machines makes the system much complex. Moreover, these machines are responsible for the production activities undertaken in an industry. If any fault occurs on machine the overall production process hampers leading to consequent loss in income and dangerous condition that may lead to hazardous accidents. Thus, there arises the need of protective system and a proper maintenance strategy to tackle down these conditions. Monitoring the machine’s condition cannot avoid breakdowns, but it may forecast the likelihood of their occurring in the future by assessing various machine metrics. Also, the protective system may protect the equipment but it could not stop the causes that may lead to failure of equipment. The machine gives the signals in the form of temperature, vibrations, oil condition, noise, quality and quantity of stator currents and voltage, etc while operating through which the abnormality may be known. A huge energy loss can be prevented if a proper diagnostic method could be employed. Motor Current Signature Analysis (MCSA) is one of the techniques used to know the condition of machine by sensing the current drawn through the motor. A proper targeted action plan can be generated after knowing the results of motor current signature analysis while running the motor, as the process is online moreover non-destructive in nature.MCSA is capable of detecting an electrical signal that is comprised of harmonic current components that are the direct by-product of one-of-a-kind rotating flux components. Variations in the normal functioning of the motor may cause modifications to the fundamental by introducing harmonic components of the motor’s supply current. In this work, a short introduction to the approach is presented, covering topics such as the basics, fault detection strategies, and the current signature of different faults conditions. A detailed analysis of amplitude of harmonics and the sidebands associated has been carried out to differentiate the faults.