Isolation of a Microgrid with High Penetration of Photovoltaic Solar Generation

RIZZATO, ADRIEL; SUVIRE, GASTÓN ORLANDO; MERCADO, PEDRO ENRIQUE

Foz de Iguazú

Simposio; 3er Simposio Iberoamericano en Microrredes Inteligentes con Integración de Energías Renovables (SiMIIER 2019); 2019

Red CYTED

The connection of photovoltaic (PV) solar generation into ac microgrids (MGs) is steadily increasing. This incorporation can bring problems onto the power quality and dynamics of the electrical grid due to the lack of controllability over the solar radiation and by the type of generation system implemented. This work presents a study of the impact on voltage and frequency of a MG when it is isolated from the bulk power system considering different scenarios. The scenarios considered are: different penetration levels of centralized or distributed PV solar generation, and the operation or non-operation of energy storage devices (SDs). For the SDs, a multi-level control scheme is suggested, which includes two control modes of operation of the SD. The first one is used to maintain constant the voltage at the point of common coupling. And the second one is used to contribute to the frequency control when important faults arise in the system. Results show that the models and developed control algorithms of the proposed SD device have worked satisfactorily. The SD contributes to the recovery of the frequency and enhances the voltage profile when the microgrid is isolated. Therefore, with the SD and control modes proposed, the power quality and the operation security of the microgrid with high penetration levels of PV generation are improved. Moreover, it is observed that the behavior of the frequency is practically the same, either centralized or distributed systems, and a better voltage profile is observed for the distributed system.