Simultaneous Enhancement of Photovoltaic System Intermittency and Damping Load Variations in Noninverting Buck-Boost Converters Using Robust Weighted Mixed-Sensitivity Control

Abstract

Due to the intermittent and uncertain nature of photovoltaic systems, their incorporation within a DC microgrid presents a challenge to primary control, which directly interfaces with the generation converter. By utilizing a weighted mixed sensitivity control, this study aims to amplify the robustness of a noninverting buck-boost converter integrated photovoltaic system in addressing the uncertainties and disturbances arising from simultaneous fluctuations in irradiance, temperature, and load. The robust control algorithm was formulated by employing frequency-weighting functions and imposing a requirement for the minimum norm of the transformation matrix to achieve robust performance and robust stability. Furthermore, the involvement of reference models in a robust control synthesis offered additional advantages in enhancing the damping of the system. Consequently, the entire design configuration could effectively establish the converter robustness against both generation and load intermittencies occurring simultaneously. The simulation and experiment results are demonstrated to illustrate the efficiency of the designed algorithm.

Keywords

• Robust control
• weighted mixed-sensitivity
• noninverting buck-boost converter
• photovoltaic system
• voltage tracking
• maximum power point