earticle

영어

In order to overcome the large power fluctuation under the maximum power point of maximum power point tracking(MPPT) algorithm based on the Perturbation and Observation method(P&O) of traditional solar photovoltaic(SPV), an optimization algorithm based on the three-order difference of power and variable step is presented. In the traditional P&O of MPPT of SPV, the first-order difference of the power is elected as the variation of the power. When the SPV is operated nearby the voltage of maximum power point, the traditional algorithm has its limitation that the power will present the approximate equal amplitude oscillation under the maximum power point because of the false judgment of the algorithm. By analyzing the relationship between the three-order difference of the power and the relative position of the operating point and the maximum power point, the next variation trend of the operating point is presented. The variable step algorithm is applied so the SPV will operate again according to the algorithm based on the three-order difference of power and variable step when the operating point cross the maximum power point first. The correctness and rationality of the proposed algorithm is tested by the results of the Matlab/Simulink.