Discrete Implementation of Sensorless IM Drive with MRAS-type Speed Estimator

In this paper the discrete implementation of a sensorless IM drive with stator current error based MRAS-type speed estimator is analyzed. The system is discretized using analogue emulation method. Two numerical integration methods, Forward Euler and Modified Euler, are compared in simulation and experimental tests. The comparison is confirmed by ITAE criterion. Moreover, the stability improvement method of the tested speed estimator, developed in continuous time domain, is used and tested in the discrete modeling and implementation. This approach also validate the stable operation of the tested speed estimation method in full operating range of the drive system.