Reconfiguration can increase the output power for a PV array under partial shadows. However

traditional reconfiguration methods consider the PV module as either totally shaded or totally unshaded

and module-based simulation is employed to evaluate the reconfiguration effect. Actually

there is an unneglectable error when treating a partially shaded PV module as totally shaded

through using a more accurate cell-based simulation. Based on the analysis of the determinant factors on MPPs' power of a PV array

a new reconfiguration method is proposed based on the exact partial shadow shape projected on the PV array. This method restructures the electrical connection among PV modules of a PV array according to the shaded cells' number (SCN) of every PV module. Extensive cell-based simulations are carried out on a PV array to verify the effectiveness of the proposed SCN-based reconfiguration method. Comprehensive comparisons among various reconfiguration methods and shadow distributions clearly show its suitability to different irregular shadows and its superiority in PV output power enhancement.