A Simple Three-Degree-of-Freedom Digital Current Controller with Dead Beat Response for AC Machines

Since current controllers are implemented digitally, digital need to be established for pursuing high performance alternating (ac) machine drives. Considering enhance the dynamic response, disturbance rejection and stability both, this article proposes a simple three-degree-of-freedom (3DOF) controller. In proposed structure, three needed coefficients have been theoretically designed, which stand response ability, rejection, of instability caused by parameters mismatch, respectively. addition, 3DOF controller can own dead beat characteristic with one-step delay compensation. Experimental results validate effectiveness in ac drive test rig.