Robust control of digital-controlled buck converter based upon two-degree-of-freedom controller

The main theme of this paper is to present a robust controller for digital-controlled power converters. The controller design and digital implementation to robust control to achieve robustness to load disturbance while retaining steady state performance of digital-controlled buck converter are presented. The robust controller is designed based upon two-degree-of-freedom control law. The specifications of the designed and implemented buck converter include: input voltage of 12 V, output voltage of 3.3 V and output current of 20 A. Experimental results derived from the DSP-based system demonstrate that the buck converter based upon the designed two-degree-of-freedom digital controller provides superior tracking and load regulation performance as compared to conventional controller.