Decentralized Secondary Frequency Controlin an Optimized Diesel PV Hybrid System

This research aims at investigating if a diesel-based isolated electrical system can be optimized by integratinga high share of solar photovoltaic (PV) generation and if thefrequency stability of such system can be improved by includingthe PV participation in frequency regulation. A case studyis developed in order to explore an island’s expansion of theinstalled generating capacity and its optimization. This studyuses the tool HOMER Energy Pro to solve the optimizationproblem and PowerFactory to verify the frequency stability ofthe proposed system. The PV integration allows for a reductionof diesel fuel consumption, emissions and generation costs.Additionally, in high PV penetration scenarios, the reducedinertia in such systems can lead to high frequency deviationsthat may trip the system protection. The study demonstratesthat the instantaneous frequency deviation after a load andgeneration imbalance can be reduced by designing the PVsto operate with an allocated reserve and a decentralizedtime-based secondary frequency control. The system remainedstable under different disturbance scenarios with high PVpenetration and reduced available inertia, indicating that highPV integration is economically and technically feasible in asmall island system.QC 20181106