Self-tuning speed regulator for CVC induction motor drive

A self-tuning speed regulator for a current vector controlled induction motor drive has been designed. Based on practical test the performance and controller parameter convergence are analysed. The analysis showed that the output noise gives drifting controller parameters and achieved dynamical properties which are different from the designed. The adaptive speed controller is robustified against the output noise by using a dead tone. The dead tone secures that the controller parameters is only updated when excitation in load occurs. This dead zone have significant effect on the robustness against output noise. The disadvantage with this approach is that it is very system specific. The optimal selection of the dead zone requires information about the forgetting factor, the variance of the output noise and the load disturbance. This is not a very restrictive requirement in this specific case