Transient maximum power point tracking for single-stage grid-tied inverter

In this paper, a new transient maximum power point tracking (TMPPT) method is proposed for single-stage grid-tied inverters. This method is different from the conventional MPPT schemes since it is based on the maximum power point (MPP) detection during transient process introduced intentionally according to the irradiance change but not based on continuous perturbation. The generated transient performance can be further improved on varying the reference photovoltaic (PV) array terminal voltage precisely as long as it can pass through the expected MPP in the new irradiation level. Henceforth, the MPP can be captured and locked, thus oscillation in steady state is avoided. The simulations conducted in both single-phase and three-phase single-stage inverters using proposed method show that the maximum power point can be quickly and accurately computed with the TMPPT algorithm even in fast changing irradiation conditions.