VARIABLE-SPEED DRIVES INCORPORATING INTERACTING MULTILOOP ADAPTIVE CONTROLLERS

A detailed design procedure for multiloop adaptive controllers for a D C drive is presented. Details of the main features of a partitioned-es timator identification scheme, the controller structure and the pole-p lacement design procedure are discussed. Results are presented for bot h twin- and triple-loop adaptive controller configurations. Drive resp onses obtained with the twin-loop configuration are compared to the co rresponding performance obtained with fixed gain controllers. The effe cts of sampling interval, tuning start-up delay, controller and estima tor initialisation and drive parameter variation are discussed, and re commendations are made. The basic transient response of the drive is s hown to be insensitive to changes in operating conditions and drive pa rameters. An important feature is that the adaptive controllers can be implemented from an initial open loop configuration thereby eliminati ng the need for any detailed a priori design. The responses obtained s how that excellent performance can be obtained from the proposed adapt ive triple-loop controller scheme over a range of rotor speeds up to 1 75% of the rated value.