A Novel Auto-Scaling Variable Step-Size Maximum Power Point Tracking (MPPT) Method for Photovoltaic System Under Changing Environmental Conditions.

This paper proposes a novel auto-scaling variable step-size maximum power point tracking (MPPT) method. The novel method solves the problems associated with conventional variable step-size method. Firstly, the conventional variable step-size method use individual scaling factor N adjusted in order to modify the step-size to balance between the precision of tracking and its divergence rate during the design stage. However, this individual scaling factor N causes the dynamic response of the PV system to be slow in the extremely irradiation change condition. To address this issue, the proposed method combines the dual scaling factors N, which are (N1) with a high value and (N2) with a low value. The N1 is used for a faster response at the beginning of the execution. In the meantime, the second N2 value is used to help stabilize the power oscillation. The proposed method can automatically adjust the algorithm's step-size to obtain a fast dynamic response that adapts to weather variations, resulting in reliable steady-state output power. Secondly, the conventional variable step-size, which is based on division of the PV module power change by the PV voltage change, endures from steady-state power oscillations and dynamic problems, particularly when subjected to sudden environmental changes. In this paper, an improvement to the conventional variable step-size method is introduced, in which the step-size of the proposed method is based solely on the change in PV power in order to completely eliminate the division calculations involved in its structure. As a result, the complexity of algorithm implementation is reduced, allowing for the use of low-cost microcontrollers to reduce system costs. Simulation results are provided through MATLAB-SIMULINK to verify the performance of the novel auto-scaling variable step-size maximum power point tracking (MPPT) method. [ABSTRACT FROM AUTHOR]