Coordination of Solid-State Circuit Breakers in Multi-Source DC Microgrids Using Inverse Time-Current Characteristic Profile

Direct current (dc) solid-state circuit breakers (SSCBs) present an ultrafast fault current isolation. In addition to modularity, they leverage the monitoring and control functions advantages. In dc power systems, SSCBs are coordinated as primary and back-up protection to implement selectivity and improve reliability. However, the low inertia of dc systems makes coordination a challenging practice. This digest explores the coordination of ultrafast SSCBs in multi-source dc microgrids. Programmable inverse time-current characteristics (ITCC) are employed to coordinate SSCBs by involving overcurrent, short-circuit, and instantaneous tripping regions. To achieve this, very-ITCC and extreme-ITCC curves are used to coordinate SSCBs for overload and short-circuit protection. To verify the effectiveness of ITCC-based coordination, experiments are conducted in single-source and two-source dc microgrid configurations.