Robust Filtering Applied to Induction Motor Control

Abstract

In this chapter, we present a practical application of robust filtering. This application involves the construction of a robust state estimate required in an induction motor control problem. This application of robust filtering to induction motor control was first presented in the paper [105]. The induction motor control problem investigated in [105] and in a related paper [108] involves the construction of a robust version of Direct Torque Control (DTC) for induction motors. The objective of the DTC induction motor control scheme is to ensure that the torque produced by the motor tracks a given torque reference signal and the magnitude of the stator flux vector tracks a given stator flux reference signal. The standard DTC approach to induction motor control has attracted a considerable amount of interest in the field of electrical machines; e.g., see [37,51,52,151,170]. However, the standard DTC induction motor control scheme is known to have problems with robustness against variations in the motor parameters. This motivated the authors of [105,108] to investigate the possibility of a robust version of DTC induction motor control. The basic idea used in these papers is to replace the observer which forms part of the standard DTC induction motor control scheme by a robust Kalman Filter of the type presented in Chapter 4.