Design and Analysis of Buck Converter Using Sliding Mode Approach

DC-DC converters play an extensive role in power electronics industries. These converters are prone to inherent errors, as a consequence these errors affect the functioning where constant output voltage operation is a must, regardless of the changes in load up to certain extent. Sliding Mode Control can handle huge non-linearities in the systems and ensures stability with respect to load and source variations as well. Despite having exceptional error reduction calibre, these controllers have least behavioural interference in the characteristics of the system on which these controllers are deployed upon. This paper focuses on the small signal (small ac disturbance) analysis of the buck converter for the continuous conduction mode(CCM) and the close loop controlling of the buck converter using sliding mode control(SMC). With these controllers in effect an authentic comparison has been done among open loop and closed loop response employed under different load and source variations. Effects of changes in ESR (effective series resistance i.e $r_{C}$ on these controllers is also brought into light in this paper and the results are recognised to be evident and substantial using MATLAB as testing platform.