Chattering-free robust nonlinear controller for an interior permanent magnet synchronous motor speed drive system

A chattering-free robust nonlinear controller is proposed for the speed control of an IPMSM drive system to compensate for the parameter uncertainties and load disturbances. First, the input-output feedback linearization technique is used with a load torque estimator. Next, the upper bounds of the uncertainties are defined in design of the chattering-free robust controller. After that, in order to derive the chattering-free nonlinear robust control laws without reducing the benefits of the sliding mode control, a new method using the sliding manifold information is proposed. Asymptotic stability of the proposed control method is proven by Lyapunov stability theory and Barbalat´s lemma. A digital signal processor, TMS320LF2407, is used to implement the proposed control scheme. The experimental results show that the proposed system can effectively reduce the chattering phenomenon and has fast transient responses, good load disturbance rejection responses, and good tracking responses.