The Effects of Nonlinear Phenomena and Control in Power Electronic Converters for Photovoltaic Applications
Rachid Darbali-Zamora& Eduardo I. Ortiz-Rivera
University of Puerto Rico, Mayaguez, PR, United States

This paper introduces the concept of nonlinear phenomena in power electronics. Power electronics is the field that combines the concepts of electronics, power and control systems. For these converters to function over a wide range of conditions, control strategies are employed. These control strategies keep the system stable and controllable. Power electronic converters are mainly composed of nonlinear components such as MOSFETs and diodes, among others. These components can cause power electronic converters to experience nonlinear phenomena (i.e., behave in a nonlinear manner), which can cause chaotic behavior. This phenomenon can cause control over a system to be somewhat difficult and can result in system instability. This analysis becomes even more complex when a variable voltage such as a photovoltaic (PV) system is used as the input voltage of the power electronics converter. This paper focuses on describing different methods used to identify and control nonlinearity in a power electronics for PV applications. Nonlinear control schemes such as Sliding Mode Control (SMC) can be employed to control chaotic responses in these power electronic converters. A simulation of a PV module connected to a Buck converter is performed under normally chaotic conditions to demonstrate the effectiveness of SMC.