A method for restoration of a fault isolation in a medium voltage, MV, network having a plurality of feeders and a plurality of normally open, NO, switches possibly in parallel with MV direct current, DC, links is presented. The method is performed in a control device of the MV network. The method includes closing at least two NO switches in parallel with MVDC links of the plurality of NO switches, being connected to a fault isolated feeder of the plurality of feeders of the MV network, and opening the closed at least two NO switches in parallel with MVDC links except one. A control device, a computer program and a computer program product for restoration of a fault isolation in a MV network are also presented.

The battery assembly includes a control unit and a DCDC converter. The control unit is configured to, when a first load is short-circuited in a process in which the battery assembly supplies power to the first load, control the DCDC converter to output a first current. The first current is greater than a maximum nominal discharge current of the battery assembly, is used to break an electrical connection between the first load and a busbar, and is less than a short-circuit protection current of the battery assembly; and/or the control unit is configured to, after a power supply encounters a power failure, control a discharge capability of the battery assembly to be greater than a maximum nominal discharge capability of the battery assembly, and supply power to a first load and a second load by using a DCDC converter.

A power supply system having a plurality of power systems is provided with a power output section in each of the power systems, an electrical load in each of the power systems, operating from power supplied by the power output section, main paths that connect the power output sections of adjacent ones of the power systems, an inter-system switch that establishes a conducting condition between the adjacent power systems by being turned on and establishes a disconnected condition between the adjacent power systems by being turned off, and an intra-system switch in each of the power systems, which is disposed on the main path between the power output section and the inter-system switch, and which establishes a conducting condition between the power output section and the electrical load by being turned on and establishes a disconnected condition between the power output section and the electrical load by being turned off.

A high voltage, direct current circuit protection system includes a number n of weakened circuit conductors connected in series to one another and being fabricated in a manner to avoid metal fatigue in response to cyclic current loads. The system also includes a corresponding number n of cutting elements operable to sever the respective weakened circuit conductors, at least one energy storage element acting upon one of the cutting elements, a control element causing a release of stored energy in the at least one energy storage element and causing a displacement of at least one of the cutting elements to sever the respective weakened circuit conductor, and a corresponding number n of arc chambers arranged proximate each respective one of the weakened circuit conductors, wherein n is an integer greater than 1 and wherein no circuit protector coordination with the weakened circuit protectors is required.

A stored electric energy distribution arrangement for distribution of stored electric energy on a vessel having one or more AC consumers, in the event of failure of a primary electric energy supply to the AC consumers has a DC-circuit. The DC circuit has a plurality of backup electric energy storage elements connected in a ring, for supplying stored electric energy to one or more AC consumers in the event of failure of the primary electric energy supply. A plurality of breaker systems are provided in the DC circuit for disconnecting one or more backup electric energy storage elements from the DC-circuit, in the event of a fault associated with that backup element.

A direct current (DC) power system includes a plurality of energy sources supplying power to a plurality of loads via a DC bus having at least one positive rail. The DC bus includes two DC bus subsections and a DC bus separator coupled between the two DC bus subsections. The DC bus separator includes a controllable switch with at least one of its terminals coupled with a terminal of an inductor to provide a current path between the two DC bus subsections during normal operation via the inductor. The controllable switch is switched off to break the current path when a fault on the positive rail is detected. Furthermore, the DC bus separator includes a diode connected in parallel to the inductor and arranged to provide a circulating current path to dissipate an inductor current in the inductor when the controllable switch is switched off.

A solar power generation network shut-off unit includes a first circuit breaker and second circuit breakers. The first circuit breaker is provided to a power line connecting a plurality of solar power generation modules and a power conditioner in series, and shut-off the supply of power from the solar power generation modules through the power line and transmits an emergency shut-off signal when an emergency shut-off button is pressed. The second circuit breakers are provided to each of a plurality of solar power generation modules, and shut-off the supply of power from the plurality of solar power generation modules through the power line and transmit a shut-off completion signal to the first circuit breaker when an emergency shut-off signal is received from the first circuit breaker.

A source-network coordination type direct-current (DC) circuit breaker based on pre-charged capacitors for an MMC based DC grid is provided. The MMC based DC grid is provided with four converter stations, each having two converters, which are in loop connection through a double-loop DC overhead line. Two ends of each DC line connecting the converters are separately equipped with DC circuit breakers for isolating a fault of the DC line. An MMC active voltage adjusting control strategy is matched with pre-charged capacitor voltage in the self-adaptive mode to provide a beneficial breaking condition for a quick mechanical switch branch, so that the fault line is effectively cut off.

A power supply control apparatus includes: a first system configured to supply electric power of a first power supply to a first load; a second system configured to supply electric power of a second power supply to a second load; an inter-system switch capable of connecting the first system to the second system and disconnecting the first system from the second system; a battery switch capable of connecting the second power supply to the second system and disconnecting the second power supply from the second system; a primary ground fault detection unit configured to cut off the inter-system switch and conduct the battery switch when a ground fault of the first system or the second system is detected by the primary ground fault detection unit; a secondary ground fault detection unit as defined herein; and a failure determination unit as defined herein.

A system for managing an insulation fault in an electrical installation includes a monitoring device, measuring devices configured to measure an electrical quantity in the installation, and switches controlled by the monitoring device. The monitoring device is configured to: [[.Math.]] detect a first insulation fault in the installation; [[.Math.]] detect a second insulation fault in the installation; [[ ]] and automatically control one of the switches associated with output terminals so as to open in order to eliminate one of the detected electrical faults, the switch to be opened being chosen depending on the location of the detected insulation faults and on predefined control laws making it possible to disconnect only some of the electrical loads.