Design of Four Fuzzy Controllers for Induction Motor Drives

This paper presents a simple method to design four fuzzy controllers of a fully digital vector-controlled induction motor drive. The outer controllers realise the usual rotor speed and flux control, while the inner controllers are used to control the d- and q-axis stator current components. The design method is based on physical relationships, because accurate model structures of electrical machines are available. The use of fuzzy controllers increases the robustness of the drive to external disturbances and load. The inherent nonlinear characteristics of the fuzzy controllers make it possible to obtain fast and accurate tracking of rotor flux and speed references, and to control the d- and q-axis current components in presence of varying load conditions, changes of mechanical parameters, process nonlinearities, and inaccuracy in the process modelling.