Sensorless vector control of induction motor compensating the variation of rotor resistance

The authors describe a compensation method for the rotor resistance variation of induction machines in a speed sensorless vector control system using an MRAS (model reference adaptive system). In the case of rotor resistance variation, an analysis of the conventional speed sensorless vector control system using an MRAS is presented. and a compensation method for rotor resistance variation using fuzzy logic is proposed. In order to confirm the performance of the proposed algorithm a computer simulation is performed. The compensator consists of a lookup table of the output for all possible combinations of the input signals and is implemented by offline processing. This simple compensator, which is added to the conventional speed estimation mechanism using an MRAS. shows considerable performance improvement