Performance Analysis of Three Phase Induction Motor Under Unbalanced Supply Conditions

Abstract

The induction motor is most essential part of an assembly line in industrial newlineapplications. Squirrel-cage IM is widely used because of its various benefits like low cost, less maintenance, ruggedness and reliability. With the development of adjustable speed drive, usage of IM has been improved. With the help of these adjustable drives control and operation becomes feasible. The velocity of the IM modifies with the change in frequency of AC current with the introduction of electronic controls. Every consumer is affected by bad quality of supply voltage whether it is at domestic or large industry consumer. Awareness of this poor power quality of supply is increasing day by day due to usage of more precise equipments as well as on the other hand ever increasing extension of non linear loads. Windings of transformer are not symmetrical, impedance of transmission lines are not same and loads are not distributed equally are few reasons of supply voltage unbalance. Even the unbalance is small, large opposite phase sequence currents can occur, because of proportionally less value of opposite phase sequence impedance. Main goal of this research is about analysing the impacts of unbalanced supply on IM in terms of transients in rotor current, ripples in electromagnetic torque and calculation of efficiency under various newlineunbalance conditions and to implement a methodology to reduce harmonics with the help of multi-level inverters. newline newline