Thermal Performance of a Three-Phase Induction Motor Under Fault Tolerant Operating Strategies

This paper presents the thermal behavior of a three-phase induction motor under direct torque control, when supplied by a three-phase voltage source inverter with fault tolerant capabilities. For this purpose, a fault tolerant operating strategy based on the connection of the faulty inverter leg to the dc link middle point was considered. The motor thermal profile is obtained through the use of nine thermocouples positioned in both stator and rotor circuits. The experimental results obtained under fault compensated operation show that, as far as the motor thermal characteristics are concerned, it is not necessary to reinforce the motor insulation properties since it is already prepared for such an operation.