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 method determines the frequency of an alternating input signal includes storing the input signal, sampling the input signal at a first sampling frequency, a first calculation and a first angular comparison of two phasors representing the input signal at two respective instants, as a function of the input signal sampled at the first sampling frequency, estimating the frequency of the input signal, and searching for a modification of frequency of the input signal. When a modification is detected the method includes, determining a second sampling frequency, sampling the stored input signal with the second sampling frequency, a second calculation and a second angular comparison of two phasors representing the input signal, at two respective instants, as a function of the input signal sampled at the second sampling frequency and of the stored input signal sampled at the second sampling frequency, and estimating the frequency of the input signal.

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 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: A method determines the frequency of an alternating input signal includes storing the input signal, sampling the input signal at a first sampling frequency, a first calculation and a first angular comparison of two phasors representing the input signal at two respective instants, as a function of the input signal sampled at the first sampling frequency, estimating the frequency of the input signal, and searching for a modification of frequency of the input signal. When a modification is detected the method includes, determining a second sampling frequency, sampling the stored input signal with the second sampling frequency, a second calculation and a second angular comparison of two phasors representing the input signal, at two respective instants, as a function of the input signal sampled at the second sampling frequency and of the stored input signal sampled at the second sampling frequency, and estimating the frequency of the input signal.

Abstract: The electrical power distribution network comprises a medium-voltage feeder having an upstream end intended to be connected to a power source. The feeder includes at least first and second consecutive protection relays positioned along the feeder and defining the ends of a first element to be monitored. The first protection relay includes a search module configured to trip a breaker to interrupt the electrical power distribution: after a first time delay when the search module detects a single-phase permanent fault in a monitoring area of the first element; and after a second time delay longer than the first time delay when the search module detects a single-phase permanent fault in an additional monitoring area located downstream of the area.