Abstract: The invention relates to a transient based method for identifying faults in an electric power transmission and/or distribution system (100) having at least one current transmission line (L12, L13, L23) comprising the following steps: —generation of a physical model of the at least one current transmission line (L12, L13, L23), the physical model depending on the fault parameters and describing the behavior of voltage and/or current transients due to the fault in the at least one current transmission line, fault parameters comprising a fault location parameter on said current transmission line (L12, L13, L23) and a fault impedance parameter, —measurement of voltage and/or currents evolution at least at one specific location in the said power system (100), —iterative simulation of the voltage and/or current evolution by the physical model at the measurement point with a set of fault parameters where at each step of iteration, simulated and measured voltage and/or current evolutions are compared and the set of f

Abstract: A control method allows the control of an installation for transmitting electricity comprising a DC transmission network including a group of electricity transmission lines that are linked to one another. The method allows the opening of at least one N-1 safety system, for each safety system being opened, the contribution to the flow of current through the group of transmission lines, originating from the converter station associated with the safety system that is opened, is removed. Furthermore, the method also allows a search for the short-circuit fault in order to identify the faulty transmission line, and an operation, implemented after identification of the faulty transmission line by the search step, of isolating the faulty transmission line by opening the line circuit breakers of the faulty transmission line.

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: A DC high-voltage electrical installation comprises a switching device for switching an electric current in the main circuit, and a method for controlling the closure of a switching device in such an installation. The installation includes a controlled variable resistor system making it possible to modify the resistance value of the resistor system seen by the current flowing through the main electrical circuit. The resistance value takes at least three distinct values: high, a lower value, and at least one nonzero intermediate value comprised between the high value and the low value. The installation includes a coordination device making it possible to control switching times of the resistance values of the resistor system.

Abstract: A detection device for detecting a short circuit current in an electrical power transmission cable having an electrical power transmission cable for a high-voltage DC network. The network includes a central core, an insulating sheath, a metal screen arranged around the insulating sheath, at least one optical fibre, arranged between the electrically conductive central core and the metal screen by forming windings around the central core in a detection region, two optical transmitters arranged at the ends of the electrical power transmission cable, two optical detectors arranged at ends of the electrical power transmission cable, two interruption devices arranged at the ends of the electrical power transmission cable when a change in the angle of polarisation with respect to a reference angle greater than a predetermined value is detected by the first optical detector.

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 control method allows the control of an installation for transmitting electricity comprising a DC transmission network including a group of electricity transmission lines that are linked to one another. The method allows the opening of at least one N-1 safety system, for each safety system being opened, the contribution to the flow of current through the group of transmission lines, originating from the converter station associated with the safety system that is opened, is removed. Furthermore, the method also allows a search for the short-circuit fault in order to identify the faulty transmission line, and an operation, implemented after identification of the faulty transmission line by the search step, of isolating the faulty transmission line by opening the line circuit breakers of the faulty transmission line.

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: The invention relates to circuit breaker apparatus for a high- or medium-voltage direct current network, the circuit breaker apparatus comprising a branch (A-A?) with a mechanical circuit breaker (S1) inserted in the network line, and, connected in parallel therewith, firstly a lightning arrestor (5) branch, and secondly a series connection of a first capacitor bank (C), a make switch (S2), and an inductor. According to the invention, the circuit breaker apparatus includes at least one resistive voltage divider (Rs) connected to the network voltage and presenting a low voltage stage (R1s) connected in parallel with the capacitor bank (C) in order to charge the capacitor bank.

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.