Power Generation Control Algorithm for the Participation of Photovoltaic Panels in Network Stability

The push for renewable energy and sustainable development has led to an ever-increasing integration of grid-tied photovoltaic (PV) systems. To maximize revenue, this resource generally operates in maximum power point tracking (MPPT) mode. However, to ensure grid stability and reliability, system operators will continue to introduce new requirements, eventually forcing PV plants to adhere to primary frequency regulation. To perform this task, PV plants will have to be capable of operating outside the MPP and varying their power production, to maintain an active power reserve, according to grid request. This paper presents an innovative model-based (MB) tracking algorithm devoted to supporting power network regulation. Thanks to the updated formulation, the algorithm can vary the power curtailment according to a reduction factor given by the power system operators. Results show the remarkable performance and accuracy of the new algorithm, providing power regulation capability in the range 20% - 100% of the maximum available power. Moreover, the impact of the employment of constant reduction coefficients on the algorithm performances has been evaluated. Validation has been performed on the base of data collected over an observation interval of more than six months. Thanks to its flexibility, this could be the basis for the participation of PV systems to frequency regulation.