Reliability Operations of The Tomia Island Microgrid

Abstract

Indonesia’s electrification ratio remained stagnant at 99.2% in 2020, largely due to its geographical challenges. Many areas still lack electricity, especially those located far from transmission lines or on small islands, where installing new infrastructure would be prohibitively expensive. For these remote communities, microgrids present an ideal solution. However, most existing microgrids rely on diesel generator sets to produce electricity. The high cost of diesel fuel limits electricity availability, with some microgrids only supplying power at night, leaving homes and businesses without electricity during the day. To address this issue, photovoltaic power plants have been introduced. While this helps reduce reliance on diesel, integrating inverter-based resources into a microgrid lowers its inertia, making it more vulnerable to instability during disturbances. Furthermore, continued use of diesel generators contributes to higher carbon emissions, posing environmental concerns that must be addressed for a more sustainable energy future. This study focuses on the microgrid of Tomia Island, a small island in eastern Indonesia. The island's microgrid has 23 buses and mainly relies on diesel generators for power. To provide electricity all day, four solar power plants were added to the system. To make the microgrid more reliable and reduce the use of diesel, wind turbines, pumped storage hydropower (PSH), and a grid-forming inverter were introduced. Load-shedding techniques were also used to keep voltage and frequency stable during disturbances. Simulations were conducted using PSCAD/EMTDC to test these improvements. Results showed that the microgrid stayed stable during events like three-phase faults, PSH trips, and diesel generator (DG) trips. It also showed potential for expansion, handling more loads with proper control. With load management, inertia, and damping adjustments, the microgrid's voltage and frequency stayed within acceptable limits during unexpected islanding or generator trips.