A novel of adaptive sliding mode controller with observer for DC/DC boost converters in photovoltaic system

摘要

Photovoltaic output voltage strongly depends on the solar irradiance and temperature. From this point of view, it is not possible to connect the PV panels and load directly. DC/DC boost converter is needed to regulate the output voltage. However, to control DC/DC boost converter is very challenging and not an easy task, since it deals with nonlinearity and non-minimum phase system. The unknown varying output voltage of the photovoltaic and unknown load resistance are common problems that needs to be considered. This paper presents modified adaptive sliding mode controller, in which adaptation mechanism is incorporated in observer designing. Observer is designed in order to estimate the unknown but bounded input voltage and load resistance. Furthermore, the controller is designed by employing PI sliding surface to eliminate steady state error under varying parameters and disturbances and to provide fast-transient response. By using this proposed configuration, the control performance is improved. The proposed method have been successfully proved by using Lyapunov theory to ensure its stability. The simulation results show that the proposed strategy can improve the voltage control of boost converter in various conditions.