Real-time efficiency estimation of an electric motor

The cost of energy is growing at a high rate, putting increasing focus on the use of energy-efficient equipment, including electric motors. The efficiency of a motor varies with load, which may be changing continuously. Hence real-time efficiency gives a better insight of the machine performance. Schemes available for efficiency estimation have varying degrees of complexity and accuracy. In this paper, we present a method of loss segregation, and requiring only current measurement to estimate the efficiency of a motor in real time. The proposed scheme is tested experimentally and compared with the direct method to validate its performance.