Design and implementation of output voltage based MPPT controller for Stand-alone Photovoltaic system

Abstract

There is an increase in interest and investment in renewable energy thus giving rise to fast development of high efficiency solar energy. Power electronics converter is the main focus which is used as an interface between the Photovoltaic output and the DC or AC utility network. Also, solar is finding greater utility in many applications like Battery operated vehicles (BOV), sail boats, quad copters etc. which requires high voltages. In such application the boost topologies finds its utility. Besides in these applications the tracking speed of the(Maximum Power Point Tracking( MPPT) algorithms has to be very fast because the irradiance changes very rapidly and thus the perturbation in duty cycle must be rapid and adaptive type to full fill the requirements of fast convergence and lower power loss due to voltage oscillations at steady state.
In this paper, an efficient adaptive step size output voltage based maximum power point (MPP) tracking (MPPT) algorithm is presented. The proposed algorithm meets the requirement of faster convergence by choosing larger perturbation steps to improve dynamic response and defining smaller perturbation steps to reduce steady state oscillations. Besides, in this technique, the voltage oscillation around the MPP is two levels as compared to three-level operation of classical MPPT technique resulting in reduced power loss. This output voltage based MPPT controller is implemented in Arduino microcontroller. A comprehensive theoretical analysis and experimental validation of the adaptive MPPT algorithm is done for the stand-alone PV system.