Effect of Voltage Supply Unbalance on Vibration of Three-Phase Induction Motor

Abstract

Abstract The three-phase induction motor is the most popular electric motor used in industry. It has a simple and robust construction as well as a higher power density. It is a self-starting motor, therefore easier to start as compared to other types of electric motor. As the other benefit, a three-phase induction motor requires fewer maintenance measures. In order to maintain proper and continued operation, many parameters of a three-phase induction motor are constantly monitored. Among them is motor vibration. This is an important operation parameter frequently used to determine repair and maintenance needs to be taken on the motor. The vibration of a three-phase induction motor might be caused by mechanical as well as electrical problems. In this paper, the effect of magnitude unbalance of a three-phase voltage supply on the vibration of a three-phase induction motor is carefully investigated. To achieve this objective, two different laboratory experiments have been conducted. The first one is a three-phase induction motor supplied from a balance three-phase voltage supply. The second one is a three-phase induction motor supplied from an unbalance three-phase voltage supply. The unbalanced three-phase voltage supply condition is achieved by making the magnitude of one phase-voltage is 3%, 4%, and 5% lower than the magnitude of the other two phase-voltages. The vibration measurement is then taken in three different directions of the motor non-drive end (MNDE), i.e., horizontal (MNDEH), vertical (MNDEV), and axial (MNDEA). The experiment data show higher vibration in all directions, MNDEH, MNDEV, and MNDEA, as a load of the three-phase induction motor increases. Further, experiment data also show that higher vibration in all directions, MNDEH, MNDEV and MNDEA, is produced when unbalanced in magnitude voltage supply is higher