Variable Structure Controller for Chaos Elimination in a Single Ended Primary Inductance Converter

Abstract

The paper attempts to off-set the circuit parasitics and the inherent switching nature of the power switch in a SEPIC (Single Ended Primary Inductance Converter) that eclipses its performance from theoretical predictions. The focus orients to design a control strategy that offers a chaotic free operation of the SEPIC. It envisages the use of a Variable Structure Control (VSC) strategy to irradiate the adverse effects of non-linear dynamics and assuage the operating range of the converter. The scheme projects the creation and elimination of this nonlinear property through time domain waveforms and phase portraits. The methodology underscores the theory to ensure an uniform rate of charging and discharging for the inductor current during the process of the converter operating the load. The scheme realizes the benefits of the mechanism through a correlation between the open and closed loop inductor current time domain waveform, with the help of adjustments in the parametric variations. The effort involves evaluating the performance using MATLAB simulation and experimental validation in a DSPIC (Digital signal peripheral interface controller) environment to illustrate its suitability for practical applications.