The use of the genetic algorithm for in-situ efficiency measurement of an induction motor

In-situ efficiency determination of working motors in an industrial plant, if done nonintrusively, is less expensive than laboratory tests, which need disconnection of the motors from the loads. This paper presents a new approach to nonintrusive in-situ efficiency determination of an induction motor. By monitoring the input voltages, the input currents, the input power and the motor speed, an equivalent circuit based optimization process using the genetic algorithm calculates the motor efficiency. The convergence and the precision have been improved by taking into account several load points in the objective function, as well as the temperature dependency of the stator and rotor resistances. A sensitivity analysis of the method to parameter changes is also presented. Experimental results confirm. The validity of this method.