The measured effects of under-voltage, over-voltage and unbalancedvoltage on the efficiency and power factor of induction motors over wideranges of load

摘要

This paper investigates the effects of over-voltage, under-voltageand unbalanced voltage on the performance of induction machines in termsof line currents, power factor and efficiency. A set of three motors of50 hp, 100 hp and 300 hp respectively, has been tested thoroughly atfive different voltage conditions: rated voltage, 10% over-voltage, 10%under-voltage, 1.25% unbalance, and 2.5% unbalance. At each one of thesevoltage conditions, a load run series was performed for every motor. Thedata obtained shows how the different motors behave similarly, in termsof line current and power factor and differently in terms of efficiency,when subject to the particular voltage conditions