Application of fuzzy sliding mode technique in controller and observer of synchronous motor

In this paper, we develop a fuzzy sliding mode technique to control the field-oriented synchronous machine and to estimate the motor speed. The sliding mode controller (SMC) is designed for a class of non linear dynamic systems to tackle the problems with model uncertainties, parameter fluctuations and external disturbances. In SMC, the high frequency chattering phenomenon results from the discontinuous term in traditional sliding mode control is highly undesirable. In this paper we use the fuzzy logic to reduce the chattering phenomena. The system stability analysis is carried out using Lyapunov stability theorem. An asymptotically stable observer is designed to overcome the problem of speed sensor and is obtained without affecting the overall system response. The simulation results show the effectiveness of the proposed control strategy with desired tracking accuracy and robustness.