Partial Shading Detection Method in Photovoltaic Systems

Abstract

The energy harvested by photovoltaic (PV) systems might be greatly reduced by partial shading conditions (PSCs). Nevertheless, energy can increase if the PV system runs at the global maximum power point peak (MPPP), which is found using global peak finding tools. The multi-use of these tools, however, will decrease the output of PV systems because they push the PV system to run outside of its power region while sweeping the I–V curve to locate the global MPP. Thus, the global peak finding tools must only be used as soon as a PSC happens. In this chapter, an accurate method is outlined for discovering PSCs by watching out for any sign of changes in voltage (positive or negative). PSC occurs when the sign of each successive voltage change remains the same for a defined number of consecutive changes. The presented method was examined on two PV array types (series and series parallel) with various different shading cases simulated on-site. The method detected all of the simulated shading cases correctly and in an appropriate timeline.