Abstract: A mechanical breaker apparatus for breaking an electric circuit comprises two electrodes that are movable relative to each other, and including an electric arc splitter device having a multitude of distinct conductive elements that are spaced apart and electrically insulated relative to one another. The splitter device has a first portion and a second portion that are movable relative to each other between: an electrical contact position; and a spaced-apart position of the two portions. The splitter device has at least one series of the distinct conductive elements that, in an electrically closed position of the electrodes of the mechanical apparatus, are arranged along the continuous electrically-conductive path for the nominal electric current through the apparatus as defined by the two portions of the splitter device in the electrical contact position.

Abstract: An undersea connection system for connecting together at least three high voltage or very high voltage undersea electric cables comprises an outer cage defining a connection space; and a connection fitting comprising a conductive connection electrode that presents a junction node from which there extend at least three branches. Each of the at least three branches of the conductive electrode includes a male terminal portion that is connected to a respective one of the electric cables in a connection zone about which there is mounted a connection sleeve made of pre-molded insulating material that receives, via its ends, firstly the male terminal portion of one of the branches of the conductive electrode, and secondly the connection end of one of the electric cables.

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: The invention relates to a modular multilevel converter (10) including a control module (12) for regulating the internal energy stored in the capacitors of the submodules of an arm of the converter, the control module being suitable for limiting the internal energy to below an upper limit and/or to above a lower limit, by using parameters measured on the DC power supply network (110) and on the AC power supply network (120) together with setpoints for the operating power of the converter.

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: A current-breaking device for high-voltage direct current includes a main conduction-line and a secondary conduction-line connected in parallel between its terminals. The main conduction-line comprises a first controlled-switch and a circuit connected in series. The circuit comprises a first current-limiter and a first capacitor connected in parallel. The secondary conduction-line comprises a second controlled-switch. These conduction lines cooperate to form an oscillating circuit that oscillates with an amplitude that is at least equal to limiting current passing through the current limiter.

Abstract: A mechanical breaker apparatus for breaking an electric circuit comprises two electrodes that are movable relative to each other, and including an electric arc splitter device having a multitude of distinct conductive elements that are spaced apart and electrically insulated relative to one another. The splitter device has a first portion and a second portion that are movable relative to each other between: an electrical contact position; and a spaced-apart position of the two portions. The splitter device has at least one series of the distinct conductive elements that, in an electrically closed position of the electrodes of the mechanical apparatus, are arranged along the continuous electrically-conductive path for the nominal electric current through the apparatus as defined by the two portions of the splitter device in the electrical contact position.

Abstract: The invention relates to a modular multilevel converter (2) having a control module (4) and a computer (10) for computing a setpoint for the internal energy of the converter stored in the capacitors of the submodules of the arms. The control module is configured to deduce, from the setpoint for the internal energy of the converter, a setpoint for the voltage across the terminals of each modeled capacitor, which setpoint is used for regulating the voltage across the points of common coupling between the converter and the DC power supply network and the voltage across the terminals of each modeled capacitor.

Abstract: A medium- or high-voltage switch (10), comprising a high-vacuum enclosure (111); first and second contacts (121, 122) that are mounted to be movable in translation relative to each other inside the enclosure (111) between an open position in which the first and second contacts (121, 122) are spaced apart; and a closed position in which the first and second contacts (121, 122) are in electrical contact. The switch (10) further comprises a conductor (210, 220, 230) arranged inside the enclosure (111) in such a manner that there exists a pressure threshold inside the enclosure (111) from which partial discharges are generated by said conductor, at least when the first and second contacts (121, 122) are in the closed position and the medium or high voltage is applied to the switch (10). The invention further relates to a switch assembly and to a method of testing such a switch.

Abstract: There is provided a vacuum switching assembly for switching an AC or DC current. The vacuum switching assembly comprises a vacuum switch.