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.

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.

A power restoration system comprising a feeder, a plurality of power sources available to provide power to the feeder, a plurality of normally closed reclosing devices electrically coupled along the feeder, at least one normally open recloser electrically coupled to the feeder, and a plurality of normally closed switches electrically coupled along the feeder between each adjacent pairs of normally closed reclosing devices. Each switch is assigned a position code having a value for each of the plurality of power sources that determines when the switch will open in response to the fault current and which power source the switch is currently receiving power from, where timing control between the reclosing devices and the switches allows the switch to be selectively opened to isolate the fault within a single feeder section between each pair of adjacent switches or between each switch and a reclosing device.

Various embodiments of the present invention are directed to a first trip unit that is configured to be coupled to a power distribution system arranged in a Zone Selective Interlocking (ZSI) arrangement. The first trip unit includes an Input/Output circuit including a ZSI input terminal and a ZSI output terminal, a heartbeat signaling module configured to transmit a second signal to a second trip unit in a lower-level zone than the first trip unit, responsive to the normal condition, a first monitoring module configured to monitor a first signal received by the first trip from a third trip unit in a higher-level zone, responsive to the normal condition, and a second monitoring module configured to detect the fault condition. Related systems, devices, and methods are also described.

A power generation and distribution arrangement that includes at least three switchgear sections. Each switchgear includes at least one or more power generators and an internal busbar in which the one or more power generators are electrically connected to the internal busbar. The internal busbar of each switchgear has one connecting end that is electrically connected to a common conductive node of the arrangement. The common conductive node includes an external interconnecting busbar between the switchgear sections.

A method for circuit breaker failure (CBF) protection in a power substation is disclosed. The power substation includes a first circuit breaker (CB), a second CB coupled to the first CB, a feeder coupled to the first CB and the second CB, a power plant coupled to the feeder, a first plurality of CBs coupled to the first CB, and a second plurality of CBs coupled to the second CB. The method includes sending a first stage tripping command to the first CB and the second CB to trip the first CB and the second CB responsive to a non-high current tripping command being active for a first period of time, and one of a current condition and an energization condition being satisfied for the first period of time, sending a first second-stage tripping command to the first plurality of CBs to trip the first plurality of CBs responsive to the non-high current tripping command being active for a second period of time, and one of the current condition and the energization condition being satisfied for the second period of time, and sending a second second-stage tripping command to the second plurality of CBs to trip the second plurality of CBs responsive to the non-high current tripping command being active for a third period of time, and one of the current condition and the energization condition being satisfied for the third period of time. The second period of time and the third period of time may be longer than the first period of time.

A method for circuit breaker failure (CBF) protection in a power substation is disclosed. The power substation includes a first circuit breaker (CB), a second CB coupled to the first CB, a feeder coupled to the first CB and the second CB, a power plant coupled to the feeder, a first plurality of CBs coupled to the first CB, and a second plurality of CBs coupled to the second CB. The method includes sending a first stage tripping command to the first CB and the second CB to trip the first CB and the second CB responsive to a non-high current tripping command being active for a first period of time, and one of a current condition and an energization condition being satisfied for the first period of time, sending a first second-stage tripping command to the first plurality of CBs to trip the first plurality of CBs responsive to the non-high current tripping command being active for a second period of time, and one of the current condition and the energization condition being satisfied for the second period of time, and sending a second second-stage tripping command to the second plurality of CBs to trip the second plurality of CBs responsive to the non-high current tripping command being active for a third period of time, and one of the current condition and the energization condition being satisfied for the third period of time. The second period of time and the third period of time may be longer than the first period of time.

Electric power Fault detection, isolation and restoration (FDIR) systems using smart switches that autonomously coordinate operations to minimize the number of customers affected by outages and their durations, without relying on communications with a central controller or between the smart switch points. The smart switches typically operate during the substation breaker reclose cycles while the substation breakers are open, which enables the substation breakers to reclose successfully to restore service within their normal reclosing cycles. Alternatively, the smart switch may be timed to operate before the substation breakers trip to effectively remove the substation breakers from the fault isolation process. Both approaches allow the FDIR system to be installed with minimal reconfiguration of the substation protection scheme.

Electric power Fault detection, isolation and restoration (FDIR) systems using smart switches that autonomously coordinate operations to minimize the number of customers affected by outages and their durations, without relying on communications with a central controller or between the smart switch points. The smart switches typically operate during the substation breaker reclose cycles while the substation breakers are open, which enables the substation breakers to reclose successfully to restore service within their normal reclosing cycles. Alternatively, the smart switch may be timed to operate before the substation breakers trip to effectively remove the substation breakers from the fault isolation process. Both approaches allow the FDIR system to be installed with minimal reconfiguration of the substation protection scheme.

A control system and method for sectionalizing switches and pulse-testing interrupter/reclosers in a distribution grid feeder which enables fault location, isolation and service restoration without requiring an external communications infrastructure to pass information between the switches. The method includes switches entering an armed state when they experience a high fault current during an initial fault event. Then, when the interrupter/recloser runs its test pulse sequence, any armed switch counts all test pulses as fault pulses, while non-armed switches count the test pulses as load pulses. Switches open to isolate the fault based on threshold values of fault pulse count and load pulse count. When an initially active interrupter/recloser completes its test pulse sequence, another interrupter/recloser begins its sequence, and all switches reconfigure their threshold values based on the new interrupter/recloser. Interrupter/reclosers after the initial device use a fast close-open event if necessary to arm some switches for proper fault-count opening.