Photovoltaic optimizer boost converters: Temperature influence and electro-thermal design

Photovoltaic (PV) systems can operate in presence of not uniform working conditions caused by continuously changing temperature and irradiance values and mismatching and shadowing phenomena. The more the PV system works in these conditions, the more its energy performances are negatively affected. Distributed Maximum Power Point Tracking (DMPPT) converters are now increasingly used to overcome this problem and to improve PV applications efficiency. A DMPPT system consists in a DC–DC converters equipped with a suitable controller dedicated to the Maximum Power Point Tracking (MPPT) of a single PV module. It is arranged either inside the junction-box or in a separate box close to the PV generator. Many power optimizers are now commercially available. In spite of different adopted DC–DC converter topologies, the shared interests of DMPPT systems designers are the high efficiency and reliability values. It is worth noting that to obtain so high performances converters, electronic components have to be carefully selected between the whole commercial availability and appropriately matched together. In this scenario, an electro-thermal design methodology is proposed and a reliability study by means of the Military Handbook 217F is carried out.