A photovoltaic power generation system includes a protection switch and a plurality of DC-DC converters. Each DC-DC converter includes a direct current bus, a DC-DC circuit, and at least one input interface. The input interface is configured to connect to a photovoltaic unit. The photovoltaic unit includes at least one photovoltaic module. The input interface is connected to the direct current bus by using the protection switch, the direct current bus is connected to an input end of the DC-DC circuit, and an output end of the DC-DC circuit is an output end of the DC-DC converter. The protection switch includes a release device and a switching device that are connected in series. The release device is configured to: when a short-circuit fault occurs on a line in which the release device is located, control the switching device to be disconnected.

A method and a device for locating faults along an energy supply chain for DC current systems. To provide a reliable fault location for DC current systems, at least one reference short circuit is generated at a known reference fault location of the energy supply chain and at least one physical property of the energy supply chain is determined during the reference short circuit. At least one physical property of the energy supply chain during the operational short circuit is determined, and a fault location of the operational short circuit is determined, taking into account at least the determined physical properties during the reference short circuit and the operational short circuit and the reference fault location.

An arc detection device includes: a low-impedance circuit connected between a node on wiring connecting the positive electrode of a DC/DC converter and a plurality of DC/DC converters, extending from the positive electrode of the DC/DC converter, and branching toward the plurality of DC/DC converters and a node on wiring connecting the negative electrode of the DC/DC converter and the plurality of DC/DC converters, extending from the negative electrode of the DC/DC converter, and branching toward the plurality of DC/DC converters; an electric current detector that detects an electric current flowing through the low-impedance circuit; and an arc determiner that determines, on the basis of the electric current detected by the electric current detector whether an electric arc has occurred.

An arc detection device includes a voltage detector connected between a first wire and a second wire to detect a voltage between the first wire and the second wire, the first wire connecting a positive electrode of a DC/DC converter and a plurality of DC/DC converters and branching from the positive electrode of the DC power source into the plurality of DC/DC converters, the second wire connecting a negative electrode of the DC/DC converter and the plurality of DC/DC converters and branching from the negative electrode of the DC/DC converter into the plurality of DC/DC converters; and an arc determiner that determines an occurrence of an arc based on the voltage detected by the voltage detector.

The present disclosure includes: a power generator; and a power line through which power generated by the power generator is transmitted to a load. The power line between the power generator and the load is provided with: a current limitation device configured to, when detecting occurrence of a fault current, limit the fault current; and a current interruption device configured to interrupt current heading for the load, in conjunction with the limitation of the fault current performed by the current limitation device.

A fault protection apparatus includes a first diode, a first switch component, a control unit, a first port, a second port, a third port, a fourth port, and a fifth port. The first port is connected to a positive common direct current bus of the common direct current bus. The second port is connected to a negative common direct current bus of the common direct current bus. The third port is connected to a positive local bus of a branch on which the fault protection apparatus is located. The fourth port is connected to a negative local bus of the branch on which the fault protection apparatus is located. The first diode and the first switch component are connected to the power system through the first port, the second port, the third port, and the fourth port.

A vehicle electrical system, particularly for a motor vehicle. The vehicle electrical system has at least two electrical system branches, a disconnecting switch device between the two electrical system branches, wherein the disconnecting switch device has a first controllable switch unit and a series circuit having a second controllable switch unit and an overcurrent protection unit, wherein the first switch unit and the series circuit are electrically connected to each other in parallel between the two electrical system branches, and a control unit which in an idle mode of the vehicle electrical system, is equipped to switch the first switch unit into an open, current-disconnecting switching state and to keep it in the current-disconnecting switching state and to switch the second switch unit into a closed, current-carrying switching state and to keep it in this current-carrying switching state. A motor vehicle with the above-mentioned vehicle electrical system is also disclosed.

There is disclosed a circuit breaker arrangement for interrupting a current flowing through a direct current (DC) transmission line including a semiconductor switching device and a pulse injection circuit configured to inductively inject into the transmission line a pulse current that opposes the current flowing through the transmission line to thereby reduce the current in the transmission line to cause the semiconductor switching device to turn-off to interrupt the path for the current flow through the transmission line.

Systems and methods are provided herein for improving distance protection in transmission lines. Such systems and methods may involve receiving one or more current and voltage inputs, and determining, based on the one or more current and voltage inputs, one or more current and voltage phasors, wherein the one or more current and voltage phasors are determined using a short window phasor estimation. Such systems and methods may also involve determining, within a single power cycle and based on the one or more current and voltage phasors, a fault in a transmission line. Such systems and methods may also involve sending, to a distance protection element and based on the determination that the fault exists, a signal to clear the fault in the transmission line, and clearing the fault in the transmission line.

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.