Shadowing Compensator for Grid-Connected Photovoltaic Generation System

The solar cell array may shade or partially shade. The maximum output current of the shaded or partially shaded solar cells is smaller than that of un-shaded solar cells, and it depends on the degree of shadowing. This can cause multiple peaks in the power-voltage (P-V) curve for the solar cell array and increases the difficultly of maximum power point tracking in the photovoltaic generation system. A shadowing compensator for the grid-connected photovoltaic generation system is proposed in this paper. This shadowing compensator uses a multi-winding fly-back DC-DC converter. The shadowing compensator supplies compensating power to the shaded or partially shaded solar cells to sustain their voltage, so the solar cell array avoids multiple peaks in the P-V curve for the solar cell array and can easily trace the maximum output power. Computer simulation is used to verify the performance of the proposed shadowing compensator. The simulation results are as expected.