Estimation of motor efficiency using measured data and nameplate information

Abstract

Induction motors consume a large percentage of the electrical power as they are commonly used in the industry. With the cost of energy increasing, the impact of motor efficiency on its operating cost is becoming significant. The performance data supplied by the motor manufacturers are usually limited and do not reflect the actual efficiency at different operating conditions. Therefore, it is necessary to establish its equivalent circuit to determine the actual performance characteristic at various operating speed. It has been recognized that the parameters of the equivalent circuit of an induction motor are not constant but speed dependent because of nonlinearities caused by skin effect and saturation.