Design and implementation of a low-cost MPPT controller for solar PV system

In this paper a maximum power point tracking (MPPT) algorithm using perturb and observe (P&O) method is discussed in order to improve the efficiency of the solar photovoltaic (PV) system. The magnificence of this method is the fact that it retains the value of the previous state and iterates for the future values of the system state. Comparing the past and the present states, the one which has more output power will be selected. ATMEGA328 microcontroller is used for constant voltage PWM control which is modulated by using a Buck-Boost converter. This control observes the panel voltage and sets the duty cycle according to the input voltages from the solar panel. As the input voltage of the solar panel increases, the duty cycle decreases and vice versa to keep the output voltage constant. We have designed a low-cost solution which will optimally convert the solar DC voltage to an AC voltage to be used in home appliances.