Comparison of Photovoltaics System Response with Constant and Variable Step MPPT Algorithm

J. Nazdrowicz, W. Tylman, W. Marańda (Lodz Univ. of Techn., Poland)

The basic foundation for obtaining maximum power is reaching the maximum operating point (Maximum Power Point), which makes it the highest possible power produced by the panel in the given solar and temperature conditions. Achieving this power requires adjusting the voltage in the work cycle, which unfortunately requires a kind of "search" by "sampling" the value of the instantaneous power at a given voltage. However, it takes a certain time to reach the maximum power, which implies power losses. One of the best known and quite simple MPPT algorithms is P&O (Perturb and Observation). Its operation, however, has a certain disadvantage related to the abrupt change of parameters, which in certain situations does not allow to obtain the optimal operating point. The paper compares the results obtained from the model with the P&O algorithm used at a constant and variable step.