Protection Coordination Design for a Microgrid with Multiple Distributed Generations in Central Sulawesi

A distribution system connected to multiple Distributed Generations (DGs) inevitably faces challenges regarding its protection system. The integration of Distributed Generation offers benefits in terms of energy source diversification and efficiency, but it also brings significant changes to power flow and fault current characteristics. One of the main challenges is the occurrence of bidirectional fault currents when DGs are connected to the distribution network. This can potentially disrupt the accuracy of conventional Overcurrent Relays (OCR), which typically detect fault currents only in a single direction, from the main grid towards the load. Therefore, implementing Directional Overcurrent Relays (DOCR) is essential to ensure precise protection selectivity and prevent false trips in areas unaffected by faults. The focus of this study is a distribution system in Central Sulawesi, which includes several hydropower and diesel power DGs. By applying DOCR with appropriate settings, the selectivity of the protection system will be accurate, particularly in managing bidirectional fault currents. To verify this hypothesis, the methodology includes load flow analysis and short circuit simulations using power system simulation software. The simulations are conducted to evaluate the protection performance with DOCR at various fault locations, especially those close to DGs. The expected outcomes of the simulations are to provide appropriate recommendations on DOCR settings to ensure reliable and selective protection for the distribution system in Central Sulawesi.