The significance of the mode of voltage imbalance on the operation and energy losses of a 3-phase induction motor

Abstract

Induction motors are key to the operation of industries due to their ruggedness, but their performance is often impaired by power supply quality issues. This has triggered research on how voltage imbalance affects the operation and performance of such motors. This study considers the effect of the manner of variation of the positive sequence voltage component on the output power, losses and sensitivity of induction motor parameters. It applies three scenarios of positive sequence variation with respect to the negative sequence component. The results show that the performance of the motor, i.e., motor losses, output power, and the sensitivity of the motor’s torque, power, and efficiency to sequence currents is dependent on the level of imbalance, and also, on the nature of the positive sequence voltage variation. Hence, the same level of voltage imbalance can trigger different operational scenarios and losses depending on how the imbalance occurs.

Keywords

• Voltage unbalance
• Motor performance characteristics
• Three phase induction motor
• Positive and negative sequence component
• Power quality
• Sensitivity analysis