Implementation of One Cycle Control Technique in Dc-Dc Buck Converter K. Subramanian * , V.K. Sarath Kumar, E.M. Saravanan and E. Dinesh Power Electronics and Drives Division, School of Electrical Engineering, VIT University, Vellore-632014, Tamil Nadu, India; ksubramanian@vit.ac.in, sarathkumarvk28@gmail.com, sarvan.em@gmail.com, dinpiolet@gmail.com Abstract A nonlinear control technique is used to controls the duty ratio (T) of a switch in switching converters. i.e., an improved one cycle control technique which is conceptual to the concept of technique of one cycle control. This one cycle control method gives firmness to the source side disturbances, but this technique shows infirmness with the load side disturbances. The proposed new improved one cycle control technique rectifies the drawbacks of one cycle control technique. It strongly rejects both source side disturbances and load side disturbances. Simulations with the buck converter results using MATLAB are given to verify the proposed work. To implement and demonstrate the feasibility of this new control technique over the disturbance, an experimental buck converter prototype has been designed, built, and tested. Keywords: DC-DC Switching Converter, Integrator, Non linear Control, One -Cycle Control Technique, PI Adjustor 1. Introduction Disturbances on power source side and load side of the system reduces the performances of the system. us, a non linear control technique utilizes the nature of the system. Switching converters system has the nature of pulsed non- linear dynamic characteristics. So we can achieve robust performance with fast and excellent dynamic response by using this one cycle control technique with proper pulsed nonlinear characteristics which provides good rejection of source side and load side disturbance than the similar system with linear feedback control technique. To control switching converters for large-signal nonlinear schemes, power electronics community has been a continuous effort in the research. e Conventional feedback control technique responds to the disturbance occurs in source is slow. e number of switching cycles is required in larger count before it regains its steady-state. us, to overcome those problem so many method where taken to consideration. e paper 1–3 proposes the Current-mode control. By using artificial ramp signal we are eliminating the occurred disturbance which is possible when duty-ratio (T) is 0.5 and above. Based on eoretical concept, the inductor current falling slope should match accurately with the artificial ramp which we have chosen. us, the source perturbations rejection on the system is done by using one cycle control method. e condition may be feasible for the buck converter along with constant control reference. If the precision is made with artificial ramp, the power source disturbance will be rejected in one cycle in the system. In switching converter, normally the inductor current falling slope will be functions of some dynamic states; therefore, the matching of generated artificial ramp with the inductor current falling slope in a transient is not possible. us, the rejection of the source side dis- turbance is not possible within one-switching cycle by using current-mode control. is technique can’t able to reject source side perturbations in one cycle and can’t fol- low the control reference under some cases irrespective of the chosen artificial ramp and converter type used in the system. In feed forward buck-converter, duty-ratio (d) is directly controlled by source voltage before the occurrence Indian Journal of Science and Technology, Vol 8(S2), 200–206, January 2015 *Author for correspondence ISSN (Print) : 0974-6846 ISSN (Online) : 0974-5645 DOI : 10.17485/ijst/2015/v8iS2/58692