Photovoltaic system MPPTracker investigation and implementation using DSP engine and buck - boost DC-DC converter

In this paper, solar radiation simulation using clearness index k_t, hour of day omega_s and day of year n is studied. Daily distributions of solar radiation are presented for various clearness indexes k_t. Additionally, taking into account the studies about solar radiation, a photovoltaic array system and a DC/DC buck - boost converter are studied. Simulation of the whole system is presented focusing on DC/DC converterpsilas control strategy so that the system operates in maximum power point (MPP) and converterpsilas output voltage remains constant. Incremental conductance algorithm is used for maximum power point tracker (MPPT) implementation. A simplest method for controlling duty cycle D and photovoltaic arraypsilas voltage by using a new variable (d = D/1-D) is proposed. Simulation results are shown and analyzed. For the implementation of this system, the dsPIC30F2010 Microchippsilas microcontroller was programmed to provide pulses to the semiconductor element of the DC-DC converter in order to track the Maximum Power Point (MPP) of the photovoltaic array.