A Novel Technique for In Situ Efficiency Estimation of Three-Phase IM Operating With Unbalanced Voltages
Maher Al-Badri, Pragasen Pillay, Pierre Angers · IEEE Transactions on Industry Applications · 2016
Three-phase voltages of any power supply cannot ever be identical due to many technical reasons. Unbalanced voltages severely impact the performance of induction motors. They also increase the difficulty of the process of efficiency estimation. This paper presents a novel algorithm for in situ full-load efficiency estimation of induction motors operating under unbalanced voltages. The proposed technique utilizes the genetic algorithm (GA), IEEE Form F2-Method F1 calculations, and pretested motors' data. The method requires a dc test, full-load rms voltages, currents, input power, and speed measurement. The proposed algorithm uses a sensorless speed measurement. The technique is evaluated by testing four small- and medium-sized induction motors with different voltage unbalance conditions. The results show acceptable accuracy.