Self-regulating maximum power point tracking for solar energy systems

Abstract

As the electric power supplied by solar arrays is dependent upon the insolation, temperature and array voltage, it is necessary to implement maximum power point tracking (MPPT) in order to move the solar array operating voltage close to the peak power point, thus drawing the maximum power from the solar array. The solar panel is integrated with a dc-dc converter, and a control algorithm, performed by a microcontroller, carries out a search to track the maximum power continuously. The method described is applied to a solar generator, an array of photovoltaic cells, in order to charge a storage battery. The dc-dc converter is responsible for the regulation of the output voltage at the peak power point while also providing a constant voltage to the charging battery. Impedance matching is also carried out by the dc-dc converter to ensure maximum power transfer. The paper describes some existing maximum power point tracking algorithms and introduces two new proposed methods.