A current limiting device for a power grid includes a first current limiting reactor; a first smart fast switch connected with the first current limiting reactor in parallel; a current transformer sleeved on a bus bar located on one side of a circuit resulting from the parallel connection of the first current limiting reactor with the first smart fast switch to monitor the current in the bus bar in real time; and a controller connected with the current transformer to control the switch-off of the first smart fast switch when the current in the bus bar is higher than a first preset value and the switch-on of the first smart fast switch when the current in the bus bar is smaller than a second preset value, wherein the first preset value is higher than the second preset value. The current limiting device improves the operational reliability of a power grid.

A module for a converter includes submodules, a first coupling inductor and a second coupling inductor which is activatable in the event of a fault. A method for controlling fault currents in a converter is also provided.

A Fault Current Limiter (FCL) comprising a magnetisable limb, an electrically conductive coil associated with the magnetisable limb and arranged to induce a field in the limb member and magnets spaced such that the coil is positioned intermediate the spaced magnets. Magnetisable shield elements are positioned at either end of the coil.

Example methods and systems for short-circuit current control in power systems are disclosed. One example method includes determining a respective maximum short-circuit current (SCC) value at each piece of equipment in the power system. A respective SCC rating of each piece of the equipment in the power system is compared with the respective maximum SCC value at the piece of the equipment. A target reactance of a variable series reactor in a mobile short-circuit control unit (MSCCU) to be installed between two points of the power system is determined in response to the maximum SCC values at one or more pieces of the equipment exceeding the SCC ratings of the one or more pieces of the equipment. A reactance of the variable series reactor is adjusted to the target reactance. The MSCCU is installed between the two points of the power system.

An electrical assembly for an AC network, including a first subcircuit electrically connected, in series, between first and second electrical points of connection. The first subcircuit includes a capacitor means, a first reactor means, and a second reactor means, in series with each other. A first switching means is electrically connected in parallel with the first reactor means. A second switching means is electrically connected in parallel with the second reactor means. A second subcircuit is electrically connected in parallel with the capacitor means, and includes a varistor means. A third subcircuit is electrically connected in parallel with the second subcircuit and includes a third reactor means and a third switching means. The first, second, and third switching means can be configured to providing a multifunctionality to the electrical assembly.

A fault current limiter is provided that comprises a fault current limiter comprising first, second and third magnetically saturable cores. The fault current limiter comprises a magnetic biasing arrangement arranged to produce a first magnetic circuit in the first magnetically saturable core, a second magnetic circuit in the second magnetically saturable core, and a third magnetic circuit in the third magnetically saturable core; first and second AC coils connected in series and connected to a first phase AC source, wherein the first AC coil is wound on a portion of the first magnetically saturable core and the second AC coil is wound on a portion of the third magnetically saturable core; third and fourth AC coils connected in series and connected to a second phase AC source, wherein the third AC coil is wound on a portion of the first magnetically saturable core and the fourth AC coil is wound on a portion of the second magnetically saturable core; and fifth and sixth AC coils connected in series and connected to a third phase AC source, wherein the fifth AC coil is wound on a portion of the second magnetically saturable core and the sixth AC coil is wound on a portion of the third magnetically saturable core.

A device for controlling change in an impedance of a power supply circuit during a fault. Further, the device includes a current jump control (CJC) component. Further, the CJC component is configured to be electrically connected with the power supply circuit in a series connection on a power source side of the power supply circuit between a power source and the power supply circuit for controlling the change in the impedance of the power supply circuit during the fault. Further, the CJC component includes an inductor. Further, the inductor is associated with at least one specific value of at least one characteristic of the inductor. Further, the at least one specific value of the at least one characteristic is based on at least one equation describing a transient input impedance associated with a practical, faulted, and finite length charged transmission line.

In an embodiment, a power delivery system includes a first current limiter and a second current limiter in parallel with each other, wherein a direct current (DC) voltage is provided to each of the first current limiter and the second current limiter; a first transformer electrically coupled to the first current limiter; a second transformer electrically coupled to the second current limiter; first differential signal traces electrically coupled to the first transformer; and second differential signal traces electrically coupled to the second transformer, wherein the DC voltage is transmitted from the first transformer to the first differential signal traces simultaneous with the DC voltage being transmitted to the second differential signal traces by the second transformer. The power delivery system includes a third transformer electrically coupled to third differential signal traces. The third differential signal traces comprise a return current path corresponding to the DC voltage.

A device for controlling change in an impedance of a power supply circuit during a fault. Further, the device includes a current jump control (CJC) component. Further, the CJC component is configured to be electrically connected with the power supply circuit in a series connection on a power source side of the power supply circuit between a power source and the power supply circuit for controlling the change in the impedance of the power supply circuit during the fault. Further, the CJC component includes an inductor. Further, the inductor is associated with at least one specific value of at least one characteristic of the inductor. Further, the at least one specific value of the at least one characteristic is based on at least one equation describing a transient input impedance associated with a practical, faulted, and finite length charged transmission line.

A substation connected to a high or extra-high voltage transmission line is disclosed. The substation includes a power line electrically connected to the transmission line. A circuit device is electrically connected by way of the line to receive the high or the extra-high voltage from the transmission line. The circuit device is responsive to a faulty condition that can arise during operation of the substation. A power voltage transformer is electrically connected to the circuit device to supply low voltage power directly transformed from the high or the extra high voltage received by the power voltage transformer from the circuit device. Example applications that can benefit from disclosed embodiments include applications for establishing a low voltage electrical power distribution in a rural or semi-rural area, such as may be used to power electric vehicle charging stations, sites involving telecommunication equipment (e.g., arrays of 5G antennas), or effective for village electrification.