Quantification of Voltage Unbalance Conditions

Abstract

This paper confers the various effects of voltage unbalance on the performance of three-phase induction motor (3-Φ IM). The need of quantification of the voltage unbalance conditions is asserted to make precise and unique assessment of the performance 3-Φ IM. Further, the slip of 3-Φ IM is evaluated under different conditions and values of degree of voltage unbalance. It is revealed that the slip is not affected with the change in degree while change of the conditions of voltage unbalance greatly affects its value. Hence, slip can be considered as suitable index for the quantification of the various conditions of supply voltage unbalance. Additionally, the variations of performance parameters of 3-Φ IM, viz., efficiency, input power, power factor, copper loss, etc., with respect to slip are investigated. It is found that, these performance parameters are not only dependent on the degree of voltage unbalance but the information of slip is also required for accurate and inimitable assessment of these performance parameters.