Model based Maximum Power Point Tracker stability over time

Photovoltaic (PV) energy production has become more and more important in the latest years. The need of energy efficiency pushed the research in this field both on material innovation and system management. As well known, an essential task in a PV system is performed by the tracking algorithm that has to assure the maximum power generation of the system. Many Maximum Power Point Tracking (MPPT) techniques have been defined. Among them a very promising category is that based on the modeling of the panel (model-based MPPTs). This technique allows to achieve performance comparable to that of traditional algorithms in steady state conditions. On the other side it features much higher performance from a dynamic point of view. An issue of MB-MPPTs is related to the model parameter identification and in particular to the stability of the model fitting over time. In this paper this stability problem will be analyzed for a MPPT previously proposed by the authors.