comparative study of variable size perturbation and observation maximum power point trackers for pv systems

perturbation and observation (p&o) maximum power point tracking (mppt) algorithms are common in photovoltaic (pv) systems due to its ease of implementation. however, operation with fixed sizeperturbations results in a trade-off between speed of response and maximum power yield in the steadystate. this paper discusses the use of fuzzy logic and non-switching zone schemes for implementing variable size perturbations for improved transient and steady-state responses. the potential performance of four different p&o algorithms is investigated by means of simulations. experimental results are then used to verifyhowthe computational burden of each algorithm and the processing speed of a digital signal processor (dsp) affect the performance of each method in a prototype. the best performance is achieved with a new strategy called non-switching zones in the vpv ×ipv plane. the power electronics converter operates with duty cycle (d) equal to 0 or 1, depending on which non-mpp region the system operates, pushing the operating point the fastest way possible towards the mpp region, for improved transient response. at the mpp region, a reduced fuzzy p&o mppt algorithm optimized for small variations around the mpp is used for reduced oscillations and increased power yield in the steady-state.