Comparative Study of Improved Energy Generation Maximization Techniques for Photovoltaic Systems

Load mismatch in photovoltaic (PV) systems may lead to considerable energy extraction losses. A DC-DC converter is usually used to match the load to the PV modules while keeping the module operating at the maximum power point (MPP), for power transfer maximization purpose. In this manner, up to 15% from the common energy extraction losses can be saved, i.e. about 6 GW when considering the 40 GW photovoltaic power generated in 2010. The converter is then driven by a pulse width modulation (PWM) scheme obtained from a MPP tracking (MPPT) controller. In this paper, two improved design approaches of the MPPT are illustrated and compared for both slow and fast changing insulation values. Both improved Incremental Conductance (INC) and improved Fuzzy MPPT techniques are fast and accurate in tracking the MPP for both slow and fast changing conditions. Some slight differences in the tracking speed, accuracy, simplicity, and cost factors make one of these two MPPT techniques superior to the other one for a certain application. Evaluation factors of both techniques are simulated and tested in this comparative study.