Double-Linear Approximation Algorithm to Achieve Maximum-Power-Point Tracking for Photovoltaic Arrays

In this paper, a double-linear approximation algorithm (DLAA) to achieve maximum-power-point tracking (MPPT) for photovoltaic (PV) arrays is proposed. The DLAA is based on the approximation that the maximum power point varies linearly with irradiation and temperature. With the DLAA, a maximum power point can be determined instantaneously. Moreover, complicated calculations and perturbations about an optimal point can be avoided. The paper also proposes a corresponding circuit to realize the DLAA. The configuration of the DLAA circuit is simple such that it is cost-effective and can be embedded into PV arrays easily. An example of implementation of a PV power supply system with the proposed MPPT is designed and the DLAA is compared with the perturb-and-observe method. Simulated and experimental results have demonstrated the feasibility of the PV power system and verified the advantages of the proposed DLAA.