Analysing active power reserve strategies for photovoltaic systems under varying shading scenarios: a comparative study

Abstract The installed capacity of grid-connected solar photovoltaic (PV) systems is increasing rapidly; therefore, in the near future, the total system inertia may possibly decrease. Reserving some active power in PV systems is crucial to manage the problem of low inertia. In this paper, we critically analyse and compare the performances of several active power reserve and frequency regulation techniques for PV systems. The discussed techniques do not use energy storage devices and are aimed at enabling the inertial capabilities of PV systems. These techniques are broadly classified according to the shading conditions and methodologies adopted for reserve generation. In this paper, we closely investigate different deloading techniques used in PV systems. In deloading, PV systems are operated at a voltage distant from the maximum power point. Further, we also address the effectiveness and suitability of the aforementioned techniques under different operating conditions. Through this review paper, we aim to provide a one-stop reference for PV researchers to select appropriately from the available reserve techniques for designing flexible DC–DC controls for PV systems.