Modified Drift-free Beta Method with Illumination Factor for Photovoltaic Systems

Abstract

Maximum power point tracking (MPPT) is crucial for photovoltaic (PV) systems to adjust gain energy under various environmental conditions. However, the limitations of conventional MPPT will lead to the energy loss caused by steady-state three-level oscillations and dynamic slow response. Moreover, the traditional P&O has a drift problem in boosting irradiation intensity. The drift problem is serious when the irradiation intensity increases rapidly. A modified drift-free beta method combined with adaptive step-size and illumination factor is proposed to avoid the drift phenomenon and ameliorate the dynamic and steady-state capability. An intermediate variable beta (β) is introduced for fast convergence speed enhancement. Furthermore, the illumination amplitude factor is developed to improve the tracking accuracy and reduce the instability of sudden irradiation changes. By incorporating the sign of current variation, the drift issue is addressed. The effectiveness of the proposed control is validated in MATLAB with various conditions.