International Journal of Electrical and Computer Engineering (IJECE) Vol. 10, No. 1, February 2020, pp. 728~737 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i1.pp728-737  728 Journal homepage: http://ijece.iaescore.com/index.php/IJECE Simulation, bifurcation, and stability analysis of a SEPIC converter controlled with ZAD Aquiles J. Morelo 1 , Simeón Casanova Trujillo 2 , Fredy E. Hoyos 3 1,2 Grupo de investigación: Cálculo Científico y Modelamiento Matemático, Universidad Nacional de Colombia - Sede Manizales, Colombia 3 Faculty of Science, School of Physics, Universidad Nacional de Colombia-Sede Medellín, Carrera 65 Nro. 59A-110, Medellín 050034, Colombia Article Info ABSTRACT Article history: Received Jun 11, 2019 Revised Sep 30, 2019 Accepted Oct 7, 2019 This article presents some results of SEPIC converter dynamics when controlled by a center pulse width modulator controller (CPWM). The duty cycle is calculated using the ZAD (Zero Average Dynamics) technique. Results obtained using this technique show a great variety of non-linear phenomena such as bifurcations and chaos, as parameters associated with the switching surface. These phenomena have been studied in the present paper in numerical form. Simulations were done in MATLAB. Keywords: Bifurcation Non-linear phenomena SEPIC converter ZAD technique Copyright © 2020 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Fredy E. Hoyos, Facultad de Ciencias - Escuela de Física, Universidad Nacional de Colombia - Sede Medellín, Carrera 65 No. 59A-110, Medellín, Colombia. Email: fehoyosve@unal.edu.co 1. INTRODUCTION Research on dynamic systems has been applied to different fields such as biology, power converters, impact oscillators, mechanical systems, etc. where a large number of phenomena [1] of a non-linear nature [2, 3] are presented. Dynamic systems defined in pieces are very important topics of study in theoretical and experimental matters, being investigated in depth in recent years. An example of systems defined in pieces, are DC–DC voltage converters, which allow the control of output voltage from a given voltage source; that is, they act as bridges for energy transfers between sources and loads, both of direct current [4]. This leads naturally to the question of how to transfer energy from the source to the load with   amplitude, which needs a  1 voltage, with the minimum loss of power. Multiple applications are presented by these converters including power sources in computers, distributed power systems, power systems in electric vehicles, etc [5, 6]. Therefore, this study has been a source of research in the fields of dynamic systems. Power converters introduce a series of non-linearities in the switching process, which is why they have been studied as variable structure systems. In [7] controllers were designed in sliding mode to work with this type of converter. Later, Carpita [8] designed a controller based on a sliding surface given by a linear proportion of the error and the derivative of the error. These two results allow working with a robust, stable, and efficient controller. However, by generating a discontinuous action of this controller, a "chattering" phenomenon arises in the system [9], which implies an increase in the ripple and distortion at the exit.