ELIMINATING SEARCH MODE DEVIATION OF MAXIMUM POWER POINT TRACKING IN PHOTOVOLTAIC SYSTEM CONTROL BY USING MODIFIED PERTURB AND OBSERVE TECHNIQUE

摘要

Maximum Power Point Tracking (MPPT) is widely used control technique to extract maximum power available from the photovoltaic (PV) module. Many MPPT techniques have been published such as perturb and observe (P&O) algorithm. Perturb and observe MPPT algorithm suffers from the deviation of MPPT when the solar irradiation level fast changing. In order to eliminate the problem of search mode deviation of MPPT, in this paper, we have proposed a modified variable step size perturb and observe technique. This modified technique is proposed to avoid the problem of rapid change to irradiance by using voltage, current and power characteristic of solar panel. In this context, a boost converter has been designed with direct duty control in order to verify the proposed modified variable step size perturb and observe algorithm. The results of the modified, conventional variable step sizes perturb and observe algorithms are compared. The simulation results showed that the proposed algorithm accurately, eliminating the mode deviation of MPPT in fast changing irradiation. The effectiveness of the proposed MPPT algorithm is verified using MATLAB/Simulink.