Indirect Vector Control of an Induction Motor with Fuzzy-Logic based Speed Controller

The aim of this paper is to present a new speed control structure for induction motors (IM) by using fuzzy-logic based speed controllers. A fuzzy controller is designed to achieve fast dynamic response and robustness for low and high speeds. Different types of membership functions of the linguistic variables and output/input characteristics are analyzed. A simple but robust structure enables a wide range speed control of the driving system. The rotor flux field oriented control (FOC) is realized by using a flux observer based on the IM model with nonlinear parameters. The control is extended to operate also in the field weakening region with an optimal rotor flux regulation. The control structure was implemented on a computer system, based on a fixed point digital signal processor (DSP). To verify the performances of the proposed driving system, simulated and experimental results are presented.