Re-synchronization of Multi-Power Islands During Blackstart with Enhanced Grid Resiliency

Restoration requires re-connection and re-synchronization of power islands and produces high transient current which leads to cascaded tripping of circuit breaker and decreasing the grid resiliency. This can be mitigated by reduction in inrush currents at the time of cold load pick up which is most vital during blackstart specially with high renewable energy penetration. This paper proposes a bottom-to-top approach for restoration and re-synchronization of a large distribution network consisting of small power islands. The proposed approach is tested on a modified IEEE 33-bus system with four renewable distributed generators. The inrush current is found decreasing by ≈49% during restoration with proposed technique which adheres to IEEE-1547 standard of re-connection, contributing to the increase in resiliency.