Proposal of a Fuzzy Controller for Radial Position in a Bearingless Induction Motor

In this paper, a radial position control approach of a bearingless induction motor is proposed. The rotor is supported by magnetic forces, which is complex to model. Generally, simplifications are adopted to determine a linearized model that hinders classical controllers' performance. On the other hand, fuzzy controllers have non-linear characteristics and do not require precise mathematical models. Instead, it uses the experience and knowledge of human operators to build a knowledge base to be used on the control. The prototype under study is a three-phase induction motor without a rated power of 1 HP, 4-pole, 220/380V and rated current 3/1.75A. It operates on a vertical axis, so there is no need to compensate for the rotor weight. The paper proposes the implementation of a Mamdani Fuzzy PD controller in order to control the rotor radial position of a three-phase induction motor by means of a Texas Instruments TMS320F28335 Digital Signal Processor (DSP). We present experimental results that validate the good performance of the fuzzy controller.