A power delivery system includes a power sourcing equipment, a powered device and a transmission cable. When the power sourcing equipment is electrically connected to the powered device via the transmission cable, an over-current detecting circuit in the power sourcing equipment is configured to detect over-current occurrence of the powered device. Meanwhile, the power sourcing equipment is configured to determine the functionality of the over-current detecting circuit based on its specific pin and provide single fault protection when the over-current detecting circuit fails.

A power delivery system includes a power sourcing equipment, a powered device and a transmission cable. When the power sourcing equipment is electrically connected to the powered device via the transmission cable, an over-current detecting circuit in the power sourcing equipment is configured to detect over-current occurrence of the powered device. Meanwhile, the power sourcing equipment is configured to determine the functionality of the over-current detecting circuit based on its specific pin and provide single fault protection when the over-current detecting circuit fails.

A method for monitoring switchgear, provided with a switching mechanism, including: monitoring an electric power supply signal to an electromagnetic actuator of the switching mechanism in order to detect the start of the supply of electric power to the actuator, monitoring an impact intensity measurement in the switchgear in order to detect the setting in motion of the switching mechanism, monitoring a parameter representative of the open or closed state of the switchgear in order to detect a change in state of the parameter, representative of an end of an opening or closing sequence of the switchgear.

The method further includes: calculating a time T.sub.ACT that has elapsed between the detection of the start of the supply of electric power to the actuator and the detection of the setting in motion of the switching mechanism of the switchgear, calculating a time T.sub.M that has elapsed between the setting in motion of the switching mechanism and the sequence end.

A method for monitoring switchgear, provided with a switching mechanism, including: monitoring an electric power supply signal to an electromagnetic actuator of the switching mechanism in order to detect the start of the supply of electric power to the actuator, monitoring an impact intensity measurement in the switchgear in order to detect the setting in motion of the switching mechanism, monitoring a parameter representative of the open or closed state of the switchgear in order to detect a change in state of the parameter, representative of an end of an opening or closing sequence of the switchgear.

The method further includes: calculating a time T.sub.ACT that has elapsed between the detection of the start of the supply of electric power to the actuator and the detection of the setting in motion of the switching mechanism of the switchgear, calculating a time T.sub.M that has elapsed between the setting in motion of the switching mechanism and the sequence end.

A time-admittance fault detection and isolation system includes a series of time-admittance switches spaced apart along the power line, each including a respective time-admittance function. Together, the time-admittance functions define a cascade trip sequence in a downstream-to-upstream direction, which autonomously causes a closest upstream time-admittance switch to a fault to trip to isolate the fault on an upstream side of the fault without communication with the time-admittance switches. The fault detection and isolation system may also include a radio communicating a trip signal from the closest upstream time-admittance switch to the fault to a closest downstream time-admittance switch to the fault. The trip signal causes the closest downstream time-admittance switch to the fault to trip to isolate the fault on a downstream side of the fault. A tie switch closes to back-feed a portion of the electric power line downstream from the closest downstream time-admittance switch to the fault.

Disclosed is a power distribution system for detecting and repairing all electrical faults, which performs at least one of immediate alarming, breaking, repairing, notifying, monitoring, and controlling according to a faulty section, place, and position where a fault occurred, if a resistance increase, an arc, an open phase, a connection failure, a partial wire disconnection, an incorrect wire connection, an abnormal voltage input, an electric leakage, a short circuit, a power imbalance occurs in three-phase or single-phase electrical equipment or in the present power distribution system.

Disclosed is a power distribution system for detecting and repairing all electrical faults, which performs at least one of immediate alarming, breaking, repairing, notifying, monitoring, and controlling according to a faulty section, place, and position where a fault occurred, if a resistance increase, an arc, an open phase, a connection failure, a partial wire disconnection, an incorrect wire connection, an abnormal voltage input, an electric leakage, a short circuit, a power imbalance occurs in three-phase or single-phase electrical equipment or in the present power distribution system.

Output circuit devices for use in electric power systems may include a first output subsystem for transmitting a first signal output via an output port to a component of the electric power system, an input subsystem for receiving and monitoring the first signal output transmitted by the first output subsystem, and a second output subsystem for transmitting another signal output to the component of the electric power system. The second output subsystem is to transmit the signal output in response to an indication from the input subsystem. Intelligent electronic devices (IEDs) and associated methods may include one or more output circuit devices.

Output circuit devices for use in electric power systems may include a first output subsystem for transmitting a first signal output via an output port to a component of the electric power system, an input subsystem for receiving and monitoring the first signal output transmitted by the first output subsystem, and a second output subsystem for transmitting another signal output to the component of the electric power system. The second output subsystem is to transmit the signal output in response to an indication from the input subsystem. Intelligent electronic devices (IEDs) and associated methods may include one or more output circuit devices.

A fault isolating device for use in a microgrid disconnected from a main power grid includes a voltage meter for detecting a voltage anomaly indicative of an electrical fault, a timer for establishing a time window that begins and ends a predetermined time after a voltage anomaly is detected, a switch that is opened at the start of the time window, and a microcontroller that determines whether to leave the switch open to isolate a faulted portion of the microgrid or to close the switch. A plurality of fault isolating devices can be distributed throughout a microgrid to isolate a faulted branch or faulted branches of an islanded microgrid without interfering with normal fuse operation when the microgrid is connected to the main power grid.