A comparative study on MPPT for photovoltaic generation systems

Perturb and observe (P&O) maximum power point tracking (MPPT) algorithms are commonly used in photovoltaic (PV) generation system (PGS) because it is easy to implement. However, conventional fixed step-size P&O exhibits a trade-off between tracking speed and tracking accuracy. By contrast, variable step-size MPPT can achieve satisfactory tracking accuracy and speed while maintains advantage of simple calculation. This paper aimed to study the performance of two different variable step-size P&O MPPT techniques. Initially, a MATLAB based PGS model is implemented and validated. Then, variable step-size MPPT methods are compared in terms of several performance indices under various operating conditions. Finally, the advantages and disadvantages of each method are then summarized.