Method and system providing feeder fault response

A method for identifying whether a fault is located on a feeder line or a lateral line in a medium voltage power distribution network, said network including a substation, an upstream recloser on the feeder line, a downstream recloser downstream from the upstream recloser relative to power flow from the substation on the feeder line, and a fuse in the lateral line, said lateral line being coupled to the feeder line at a tap location, said upstream and downstream reclosers being operable to allow or prevent the power signal from flowing through the recloser, the method comprising:

• measuring a current and voltage on the feeder line in the upstream recloser;
• identifying that a fault current is present indicating a fault on the feeder line or the lateral line in the upstream recloser;
• determining in the upstream recloser a fault location of the fault by identifying a fault voltage using the measured current and voltage;
• determining in the upstream recloser a first distance from the upstream recloser to the fault location using the fault voltage;
• measuring a downstream voltage on the feeder line in the downstream recloser during the fault;
• transmitting the downstream voltage from the downstream recloser to the upstream recloser;
• determining in the upstream recloser a second distance from the upstream recloser to a last location of the fault current on the feeder line using the downstream voltage;
• determining that the fault location is on the feeder line or the lateral line by comparing the first and second distances where if the first and second distances are the same or nearly the same the fault location is on the feeder line and if the first and second distances are not the same the fault location is on the lateral line;
• and
• opening a switch in the upstream switching device if it is determined that the fault location is on the feeder line.

A system for identifying whether a fault is located on a feeder line or a lateral line in an electrical power distribution network, the network including a power source, an upstream switching device on the feeder line, a downstream switching device downstream from the upstream switching device relative to power flow from the power source on the feeder line, and a fuse in the lateral line, the lateral line being coupled to the feeder line at a tap location, the upstream and downstream switching devices being operable to allow or prevent the power signal from flowing through the switching device, the system comprising:

• a voltage sensor and a current sensor on the feeder line in the upstream switching device having a voltage output corresponding to a feeder voltage and a current output corresponding to a feeder current;
• a fault detection processor couple to the current sensor, the fault detection processor configured to identify that a fault current is present on the feeder line or on the lateral line in the upstream switching device;
• the upstream switching device configured to identify a fault location of the fault by identifying a fault voltage at least using the voltage output;
• a downstream voltage sensor on the feeder line in the downstream switching device, the downstream voltage sensor configured to provide a downstream voltage output to the upstream switching device;
• wherein
• the fault detection processor is configured to determine that the fault location is on the feeder line or the lateral line based on the downstream voltage and the fault voltage and to open a switch in the upstream switching device if it is determined that the fault location is on the feeder line.