In-Service Efficiency Estimation with the use Modified Air-Gap Torque Method for Squirrel-Cage Induction Motor

摘要

Squirrel-cage induction motors are used in many industrial applications. Their advantages such as low price and low failure rate has caused the expansion of these machines in many industries compared to other types of electrical machines. These motors are often below face value because they are oversized in relation to the load with which they work most of the time. Squirrel-cage induction motors are supplied from frequency converters. Then motors can work with variable speed. In these case the motor efficiency changes as a function not only load but also frequency. Economic considerations associated are going to move to low energy consumption. Thas why it is necessary to monitoring the efficiency factor of the motor, and ultimately control of his work in energy-efficient [1-3].