The present invention discloses a DC solid-state circuit breaker with self-adapt fault current limiting capability. The topology of the DC solid-state circuit breaker is a H-bridge circuit consisting of two unidirectional breakable bridge arms and two series-connected diode bridge arms, wherein the two unidirectional breakable bridge arms are connected in series to the two series-connected diode bridge arms in a same direction to form two series branches, respectively; the series branches are connected in parallel; a series branch formed by a DC reactor L and a DC biased power supply is connected to the PCC between the two unidirectional breakable bridge arms and the PCC between the two series-connected diode bridge arms; the DC line is connected to the two PCCs, respectively.

This application discloses a system that may comprise at least a portion of a supply network. The system may further comprise a load controller that controls current flow with a current level of I1 into a load network that provides power to one or more loads from the at least a portion of the supply network according to a preprogrammed load curve. The system may also comprise a protection system that isolates the at least a portion of the supply network from the load controller in response to detecting a current pattern that is inconsistent with the preprogrammed load curve.

This application discloses a system that may comprise at least a portion of a supply network. The system may further comprise a load controller that controls current flow with a current level of I1 into a load network that provides power to one or more loads from the at least a portion of the supply network according to a preprogrammed load curve. The system may also comprise a protection system that isolates the at least a portion of the supply network from the load controller in response to detecting a current pattern that is inconsistent with the preprogrammed load curve.

Systems and methods to isolate faults and restore power are described herein. For example, an intelligent electronic device (IED) may receive a blocking signal indicating a fault is detected on a power line. The IED may obtain one or more current measurements of the power line. The IED may determine that a fault is not present on the power line at the IED based on the one or more current measurements. The IED may trip a first current interruption device of the IED The IED may send a close permissive signal to another IED indicating that the other IED is permitted to permitted to close an open current interruption device of the other IED to restore power to one or more loads.

Systems and methods to isolate faults and restore power are described herein. For example, an intelligent electronic device (IED) may receive a blocking signal indicating a fault is detected on a power line. The IED may obtain one or more current measurements of the power line. The IED may determine that a fault is not present on the power line at the IED based on the one or more current measurements. The IED may trip a first current interruption device of the IED The IED may send a close permissive signal to another IED indicating that the other IED is permitted to permitted to close an open current interruption device of the other IED to restore power to one or more loads.

In a multi-phase power grid fed by a power source, earth fault (460) is located by means of a power supply source synchronized with the power grid, which is connected between a zero point of the grid and earth. In a fault current compensation mode (420), a control unit controls the alternating voltage source to compensate for any ground fault current in the power grid to a value below a threshold level. In a fault detecting mode (430), the control unit gradually adjusts the output voltage of the alternating voltage source with respect to amplitude and/or phase angle (440). A change of zero-sequence current and zero-sequence admittance between the alternating voltage source and a fault location is measured (450) by means of at least one detector. The at least one detector is communicatively connected to the control unit and reports recorded measured values representing zero-sequence current and/or zero-sequence admittance to the control unit. In the fault detecting mode, the control unit localizes a ground fault (460) based on at least one of said measurement values representing changes of the zero-sequence current and/or zero-sequence admittance, upon which an affected branch is disconnected (470) or the system switches to the fault compensation mode (420).

Systems and methods to isolate faults and restore power are described herein. For example, an intelligent electronic device (IED) may receive a blocking signal indicating a fault is detected on a power line. The IED may obtain one or more current measurements of the power line. The IED may determine that a fault is not present on the power line at the IED based on the one or more current measurements. The IED may trip a first current interruption device of the IED The IED may send a close permissive signal to another IED indicating that the other IED is permitted to permitted to close an open current interruption device of the other IED to restore power to one or more loads.

Systems and methods to isolate faults and restore power are described herein. For example, an intelligent electronic device (IED) may receive a blocking signal indicating a fault is detected on a power line. The IED may obtain one or more current measurements of the power line. The IED may determine that a fault is not present on the power line at the IED based on the one or more current measurements. The IED may trip a first current interruption device of the IED The IED may send a close permissive signal to another IED indicating that the other IED is permitted to permitted to close an open current interruption device of the other IED to restore power to one or more loads.

A direct current electrical network includes nodes linked by branches and protection elements mounted on the branches, each protection element includes a central processing unit, a current sensor, a current limiter device and a circuit breaking device, wherein: the current sensor is configured to determine the direction of the current in the branch relative to the node with which said protection element is associated; the central processing unit is configured to select, as a function of the direction of the current, a selected threshold value as one of a first value or a second threshold value greater than the first threshold value in absolute value, and to compare the value of the intensity of the current to the selected threshold value; and the current limiter device is bidirectional and is configured to limit the current passing through the branch to the selected threshold value.

A method for controlling a power distribution network includes receiving, by an electronic processor, a fault indication associated with a fault in the power distribution network from a first isolation device of a plurality of isolation devices. The processor identifies a first subset of a plurality of phases associated with the fault indication and a second subset of the plurality of phases not associated with the fault indication. The first and second subsets each include at least one member. The processor identifies an upstream isolation device upstream of the fault. The processor identifies a downstream isolation device downstream of the fault. The processor sends an open command to the downstream isolation device for each phase in the first subset. Responsive to the first isolation device not being the upstream isolation device, the processor sends a close command to the first isolation device for each phase in the first subset.