Robust maximum power point tracking of photovoltaic generators based on real-time dynamic conductance estimation

In this paper, an innovative approach aimed to robustify maximum power point tracking, intended for managing a photovoltaic generator is presented. The method exploits the bond between photovoltaic generator static and dynamic conductance, utilizing their sum as the base controller management mutable data of the maximum power point tracking loop. Environmental condition and operating point are the significant variables that influence dynamic and static conductance values, consequently, when using a controller which design to a single nominal operation point a nominal response is un-achievable, thus, system response can vary from overdamped to underdamped. Notwithstanding, dynamic and static conductance sum calculation always yield zero when the photovoltaic generator operates at the maximum power point. Therefore, forcing the sum to zero drives the system to be at maximum power point no matter the states of the environmental conditions. Uneven and variable response time calls for implementing a disturbance observer as a counteraction to the nonlinear maximum power point tracking loop regulation variables, operation point, and environmental condition variations. Test results of implanting disturbance observer revealing a unified and nominal response all over the operation range, therefore the proposed approach enhanced and robustified the common integral controller.