Voltage Unbalance Impacts on Temperature of IE2, IE3 & IE4 Class Induction Motors

Abstract

Energy efficiency actions is a shared policy goal of many governments in the world. In that sense, drive systems represent an important opportunity for energy savings. With an average of 20.1 million installed motors that represents approximately 30% of total energy consumption In Brazil, old motors sub-stitution for new and more efficient technologies is now a reality. The present work analyses the impact of voltage unbalance (VU) with under and over voltage on the line current and temperature of electric motors classes IE2, IE3 and IE4, the latter being a hybrid permanent magnet and squirrel cage motor. To do this, six different unbalance voltage conditions were applied to each motor while measurements were made to capture the main variations for each technology. The results show how the voltage unbalance results in considerable uneven increases in current and temperature in each motor, it was also observed how the hybrid permanent magnet motor shows less dependence on voltage variations, mainly with undervoltage.