“…It is well defined in the literature that the accuracy of the MPP-tracking process depends on the correctly selected perturbation frequency, which guarantees that the PV voltage and current measurements are performed at the moment when the PV power transient is properly settled down [10,12,13,24], -the correctly selected minimum perturbation step size to producing high enough PV-power variation, which overcomes the combined power changes induced by the irradiation change during the perturbation interval and the PV voltage/current ripple [10,12,13,24].…”