Shading Fraction based Global Maximum Power Prediction for Photovoltaic Energy Conversion Systems

Maximum power point tracking is the key to optimum utilisation of photovoltaic energy conversion systems. With increasing photovoltaic system installations in dense areas, the panels become prone to partial shading. In the event of partial shading, it becomes all the more important to operate the system at global maximum power point, failing which the system loses high amount of power. If the PV system does not incorporate shade-aware design: long operations under partial shading lead to potential system failure. This work identifies several possible output characteristics of PV panel arrays under different shading conditions along with a method of identifying the global maximum power point in each case. Using this method, given shading fraction on a PV array, many global MPPT algorithms can be developed and implemented. The understanding of panel output characteristics also facilitates the prediction of partial shading and the shade pattern, which prevents hotspot formation and system degradation.