An Active Power Control Strategy for grid-connected PV Station

This paper presents an advanced control strategy designed for photovoltaic (PV) power systems aimed at optimizing the active power output of a PV plant in order to actively participate in the primary frequency response of the power system. In detail, the strategy allows the PV system to switch between two different operating modes according to the actual demand during the delivery of active power to the grid. By establishing a specific active power reference target, the method provides guidelines for the regulation of the output power of the PV plant. When the actual output power is lower than this reference value, the system will activate the maximum power point tracking (MPPT) mode to maximize energy capture, at which time the system does not participate in the primary frequency regulation of the grid. Conversely, when the output power of the PV plant exceeds this reference value, the PV units are adjusted to operate at an optimized point that deviates from the MPPT, thus creating additional regulation reserve power. This reserve power facilitates being dynamically called upon when the power system performs primary frequency regulation, enhancing the stability and responsiveness of the grid.