Subnetwork A ~ ~ Substation Subnetwork B ~ Generation Subtransmission Circuit Transmission Circuit VSC Station ~ dc Circuit Autoswitch Subnetwork C ~ Subnetwork D FIG 1 An effective strategy to increase urban grid resiliency is to strategically split the network into smaller subnetworks under emergency conditions to minimize the risk of spread outages. Emergency power and dynamic voltage support can be provided by such dc interties between the split subnetworks. (Figure courtesy of ABB.) Black Start Capability and Fast Restoration In the event of a local blackout of one subnetwork at one end of the HVDC intertie, the converter station can operate in standby mode with the HVDC link energized from the other end converter. HVDC intertie can significantly simplify the black start sequence and enable fast system restoration in a controlled procedure by the network control center via remote supervision. System restoration proof of concepts has been achieved in actual grids, e.g., at the Åland Islands in Finland [1]. As demonstrated, even when the HVDC link is not in active operation, the system can be restoredhttp://teledynelecroy.com/static-dynamic-complete