A new variable step size INC MPPT method for PV systems

摘要

Maximum power points tracking (MPPT) techniques are widely utilized in photovoltaic (PV) systems to operate at the peak power of PV array which depends on solar and ambient temperature. Between all the MPPT strategies, the incremental conductance (INC) algorithm is extensively employed due to the high tracking accuracy at steady state and good adaptability to the rapidly changing atmospheric conditions. In this paper, a novel variable step-size incremental conductance MPPT algorithm is used in solar array power systems with direct control method, which automatically adjusts the step size to track MPP without the proportional-integral control loop. Compared with conventional INC and variable step-size INC method, the proposed method can largely improve the MPPT response speed and accuracy at steady state simultaneously without steady-state oscillation. The proposed algorithm was tested in MATLAB/SIMULINK environment. Results show the feasibility, a faster response speed and higher tracking accuracy in changing irradiance.