Research and Implementation of Fractional Order Controller in AC Servo Motor System

AC servo control system usually uses traditional PI controller to control current and speed. The traditional PI controller is mature in design and has good control effect, but it also has some shortcomings, such as inaccurate parameter design and sensitivity to system parameter changes and so on. When the controlled object’s parameter changes, the fractional $\text{P}\mathrm {I}^{\lambda }$ controller is robust, control effect is better than the traditional PI controller, and the difficulty of implementation is similar to that of traditional PI. In order to achieve higher performance of AC servo control system, In this paper, fractional $\text{P}\mathrm {I}^{\lambda }$ controller is used instead of traditional PI controller, the fractinal order control theory is also studied, the structure and frequency characteristics of fractional order $\mathrm {PI}^{\lambda }$ controller are analyzed, at the same time, the parameter tuning of fractional $\mathrm {PI}^{\lambda }$ controller is also carried out.