The efficiency improvement of series connected PV panels operating under partial shading condition by using per-panel DC/DC converter

The influence of partial shading on series connected photovoltaic (PV) panels lowers the energy yield of the PV power generating system. It causes multiple maximum power points (MPPs) on the power-voltage (P-V) characteristic of a PV string connecting to a converter/inverter unit. With conventional maximum power point tracking (MPPT) algorithm, the controller may track a local MPP, instead of the global one, resulting in a reduction of output power of the PV system. Even if the MPPT techniques may be able to track the global MPP, the resultant output power obtained always less than the summation of the allowable maximum power of independent PV panels operating under the same condition. The aims of this paper are to study and propose the method which uses a concept of individual DC/DC converters per panel in order to improve the performance of the PV power generating system operating under partial shading condition. Matlab/Simulink simulation is conducted to show the efficiency improvement of the proposed system.