Model following servo control of CSI-IM vector control system

An application of model-following servo (MFS) control to the current source inverter (CSI)-fed induction motor (IM) vector control system is studied. The MFS control is a kind of two degree-of-freedom control, and the controller is designed systematically by using optimal regulator theory. For the speed control of IM, a comparison between the MFS control, conventional PI (proportional plus integral) control, and PI control with a load torque observer is made under the assumption of ideal vector control. A linear model in which a PI current controller and the change of rotor resistance are considered is presented. The robustness of the MFS control is discussed by examining the trajectories of poles and zeros and the transient responses.<<ETX>>