Two steps towards speed estimation and encoderless identification of two-mass-systems with extended speed adaptive observer structure

This paper presents a two-step identification procedure for two-mass-systems in speed-sensorless operation based on frequency response measurement. By utilizing a speed adaptive observer structure, the encoderless control technique for the induction machine provides estimated speed information that can serve for a basic identification of the mechanical system. The resulting frequency response does not yield the whole system characteristic but allows the extension of the speed adaptive observer structure in the second step. Correct system identification is afterwards achieved, which determines the estimated motor speed to be correctly calculated with the new introduced extended speed adaptive observer structure.