An improved P&O MPPT algorithm for single stage three-phase grid integrated solar PV system

Abstract

This work presents an improved perturb and observe (P&O) algorithm based MPPT (Maximum Power Point Tracking) for a single stage solar photovoltaic (PV) array integrated with a three phase grid. Due to simple implementation and efficient tracking, the P&O approach of extracting maximum power from a PV array is very popular and efficient tracking technique among all MPPT techniques. However, the major pitfalls of this technique are that P&O MPPT is affected from drift, the outcome of drift occurring is much disapproving when there is a quick rate of increment in insolation. Drift takes place because of erroneous judgments taken by traditional P&O technique at the initial step alteration in voltage reference throughout the rise in insolation. An improved P&O algorithm is proposed here to improve the drift issue by deploying the details of variation in PV current (ΔDLI <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pv</inf> ) to make the judgment in extension to the variation in PV power (ΔDLP <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pv</inf> ) and variation in PV voltage (ΔDLV <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pv</inf> ). In this PV system, a VSI (Voltage Source Inverter) and three phase grid are used. In a three phase distribution feeder network for indemnify, the quality of power as per an IEEE-519 standard on harmonics, it satisfies the power quality norms. So, for availing the real power feeding to the grid and to sustain the terminal voltage constant at the PCC (Point of Common Coupling) with sinusoidal grid voltages and grid currents, this system works well simultaneously with improved performance of P&O technique. The Matlab/Simulink is used for simulation and modelling of proposed system and the behavior of proposed MPPT algorithm has been examined for various insolation levels and different environmental situations on an experimental system which is established in the laboratory