A Master-Slave-Based Power Reserve Control Approach for Solar PV Participation in Frequency Control

Due to diminishing system inertia, system operators currently mandate solar photovoltaic (PV) systems to participate in frequency control. In the literature, the standard approach for achieving this has been to combine a PV system with energy storage. However, it has a number of technical and financial drawbacks. With the goal of providing power reserve control (PRC) and allowing PV systems to participate in frequency regulation, this article offers a novel storage-free master-slave-based power control technique for solar photovoltaic (PV) systems. A substantially small-rated master PV operating in maximum power point (MPP) mode estimates the irradiance and temperature online, which are further utilised to evaluate the entire PV curve of the slave PVs. A novel adaptive voltage control mechanism (inner control) is designed for rapid conversion of a power instruction into an appropriate voltage instruction for the linking DC-DC converter. The proposed method merges the MPP and PRC operating regimes into a single integrated regime, enabling a seamless transition between the modes. Additionally, an inertial and damping control scheme is integrated with the proposed PV system, with active power reserves maintained to modulate the PV power reference of the inner controller in response to system requirements. The proposed control strategy is verified on a three-area test system and the Kundurs multi-machine test system in order to quantify the impact on system performance. The findings show that the suggested control method significantly lowers frequency and tie-power variations.