Drift Free Variable Step Size Perturb and Observe MPPT Algorithm for Photovoltaic Systems Under Rapidly Increasing Insolation

The characteristic of a Photovoltaic (PV) panel is most affected by the incident solar insolation temperature, shading, and array configuration. Maximum power point tracking (MPPT) algorithms have an important role in harvesting maximum power from the solar PV arrays. Among the various MPPT methods Perturb and Observe (P&O) algorithm is the simple and efficient one. However, there will be a drift problem in case of increase in insolation. This drift will be more under rapid increase in insolation. To improve the speed of tracking the Maximum Power Point (MPP), a variable step size P&O (VSSPO) is developed. The drift problem will be more in the case of VSSPO as it will have a larger step size for an increase in insolation. In this paper, the maximum output power extraction from Solar PV under rapidly increasing insolation conditions by a drift free P&O (DFP&O) as well as drift free VSSPO (DFVSSPO) method is presented.