A new two-stage MPPT technique for enhancing the performance of PV system
摘要
Attributable to the impact of partial shading conditions (PSC), the output characteristic curve of photovoltaic (PV) arrays is susceptible to multiple peaks, under which circumstances conventional maximum power point tracking (MPPT) techniques may prove to be ineffective. This article proposes a novel two-stage MPPT method, termed the improved Harris Hawk optimization (IHHO) and sigmoid function-based Perturb and Observe (SP&O). The standard Harris Hawk Optimization (HHO) algorithm is improved by introducing a nonlinear dynamic energy factor based on the distance between the optimal individual and the current individual vector, which improves the balance between global optimization and local optimization. The dynamically changing population balances optimization accuracy and speed. Using the Sigmoid function to optimize the dynamic step size of P&O, making the algorithm faster and more accurate, and eliminating steady-state oscillations. A comparative analysis is performed against VPSO-LF, Spline-MPPT, HHO, IGWO, and P&O methods under PSC. The results demonstrate that IHHO-SP&O achieves minimal power loss, rapid tracking speed, and no steady-state oscillation.