Abstract: A method of protecting a high-voltage network comprising the steps for maintaining first controlled switches closed and second controlled switches open; measuring voltage and current on high-voltage interfaces; communicating the direction of the current to the other end of a high-voltage line; for each node: identifying a fault; verifying that the current is lower than the current interruption capability of the high-voltage interface switch and opening this switch.

Abstract: The invention relates to a method of protecting a network comprising: electrical lines (120, 130, 230); three interconnection nodes (10, 20, 30) with: a high-voltage interface with controlled switches; a local network interface; local networks for each respective node (10, 20, 30), comprising: an MMC converter (16, 26, 36); a protection circuit with, in parallel, a first controlled switch (14) and a first limiter (15), a second controlled switch (12) and a second limiter (13). The method comprising the steps for: maintaining the said first switches (14) closed and the said second switches (12) open; measuring voltage and current on the high-voltage interfaces; communicating the direction of the current to the other end of a high-voltage line; for each node: identifying a fault; verifying that the current is lower than the current interruption capability of the high-voltage interface switch and opening this switch.

Abstract: An item of interconnection equipment for a high-voltage DC grid includes first and second terminals for connection to first and second lines of a high-voltage DC grid, a third terminal for connection to a local station or a line of the high-voltage grid, a node connected to the first to third terminals, a first superconductor current limiter and a first controlled switch connected in series between the first terminal and the node, a second superconductor current limiter and a second controlled switch connected in series between the second terminal and the node, a third superconductor current limiter and a third controlled switch connected in series between the third terminal and the node, and a current injector configured to inject an electrical current into the node.

Abstract: An item of interconnection equipment for a high-voltage DC grid includes first and second terminals for connection to first and second lines of a high-voltage DC grid, a third terminal for connection to a local station or a line of the high-voltage grid, a node connected to the first to third terminals, a first superconductor current limiter and a first controlled switch connected in series between the first terminal and the node, a second superconductor current limiter and a second controlled switch connected in series between the second terminal and the node, a third superconductor current limiter and a third controlled switch connected in series between the third terminal and the node, and a current injector configured to inject an electrical current into the node.