Design, Simulation and Real-time Implementation of a Maximum Power Point Tracker for Photovoltaic System

Maximization of power from a solar photovoltaic (PV) module is of special interest as the efficiency of the solar PV system is very low. A maximum power point tracker (MPPT) is needed to operate the PV array at its maximum power point. The present work describes the design and implementation of a MPPT for the solar PV array connected to a resistive load. The design consists of a dc-dc boost converter (also known as step up converter) and a control section that uses an ATmega32 microcontroller. The control section obtains the information from the PV array through microcontroller’s Analog and Digital (A/D) ports and hence performs the pulse width modulation (PWM). The incremental conductance method with some modification is used as an algorithm to track the maximum power point of the PV array. By using this algorithm the MPPT is able to track the maximum power point of the PV array very quickly under rapidly changing atmospheric conditions. The simulation is carried out in PROTEUS ISIS environment. The program is written in C and then is complied by a freeware version C compiler “WinAVR”. The power tracker is developed and tested in the laboratory. It is observed that the use of MPPT enhances the output power by 25%. The measured parameters such as the panel voltage, current, power and corresponding duty cycle are displayed on the LCD.