Off-Line Efficiency Mapping of Induction Motors Operated in Wide Torque-Speed Ranges

In the context of a progressive component virtualization for energetic assessments in variable speed and load operations, this paper presents a methodology for computing the efficiency maps of three-phase induction motors. The proposed approach is based on the conventional machine equivalent circuit to quickly obtain a set of efficiency maps at different machine temperatures and supply voltage levels. The well-known no-load and locked-rotor tests are used to determine the motor parameters at different frequencies and voltages, taking into account the machine nonlinearities and the iron losses. The approach has been validated on an 11 kW, 4 poles, 50 Hz induction motor tested in different operating conditions.