Robust Design of Perturb & Observe Maximum Power Point Tracking

The perturb & observe (P&O) maximum power point tracking (MPPT) is widely used in photovoltaic (PV) systems due to its simplicity and reliability. To optimize the performance, two parameters should be designed, i.e., step size and perturbation frequency, in practice. However, for the step size, the prior-art design could not perfectly balance the static and dynamic performance of the P&O MPPT. Moreover, its behaviors under dynamic irradiance variations were barely revealed. As such, in this paper, the operation principles and the corresponding characteristics of the MPPT are analyzed. Then, the mathematical model to describe the impact of the design parameters is presented. More importantly, a robust design guideline taking into account both the static and dynamic irradiance conditions is proposed. Finally, the proposal is validated through simulations and hardware-in-the-loop (HiL) tests, where the effectiveness of the theory is verified and great design performance is shown.