Perturbation and observation as MPPT for highly penetrated grid-integrated PV generator considering symmetrical three-phase fault

This paper presents perturbation and observation (P&O) as maximum power point tracking (MPPT) technique applied on grid-integrated PV generator. The interfacing is carried out via DC-DC buck-boost converter, three-phase sinusoidal DC-AC inverter, LC filter, transformer and two identical transmission lines. Large-signal stability analysis has been carried out considering symmetrical three-phase to ground fault as a case study at the middle of one of the transmission lines. The idea behind introducing the DC-DC converter is to adjust its duty cycle using the P&O algorithm such that to extract the maximum power available in the PV generator at all practical solar irradiance levels. The results show that the highly penetrated grid-integrated PV generator can keep the stability of its operating point despite the large-disturbance considered. It is also concluded that overshoot and settling time of the power system are highly affected by the fault clearing time and solar irradiance level. The higher the solar irradiance level is, the higher the critical clearing time, the larger the overshoot and the lower the settling time tend to be.