Distribution network coordination in the presence of intermittent faults

A method for detecting intermittent faults in an electrical feeder line, the method comprising:

• measuring a current flow through a recloser in the feeder line;
• identifying that a fault current is present indicating a fault in the feeder line;
• opening a switch in the recloser in response to detecting the fault current;
• closing and opening the switch in a pulsed manner for a first pulse duration time;
• and
• closing and opening the switch in a pulsed manner for a second pulse duration time that is longer than the first pulse duration time if it is determined that no fault current was present during the first pulse duration time.

A system for detecting faults in an electrical power distribution network, the network including a power source, a feeder line coupled to the power source and receiving a power signal therefrom, a plurality of lateral lines coupled to the feeder line and receiving the power signal from the feeder line, and a plurality of loads coupled to and receiving the power signal from the lateral lines, said feeder line including a switching device that monitors the power signal on the feeder line and is operable to the power signal from flowing through the device, the system comprising:

• a current sensor associated with the switching device to measure a current flow through the switching device and to provide a current signal to a controller;
• the controller being configured to receive the current signal and to determine therefrom that a fault current is present indicating a fault in the feeder line or one of the lateral lines;
• the controller being further configured to provide an open signal to the switching device to cause a switch in the switching device to open in response to the signal when a fault in the feeder line is indicated;
• the controller being further configured to provide a first pulse signal to the switching device to cause a pulse generator within the switching device to generate a first pulse having a first pulse duration time;
• the controller being further configured to analyze network voltages and the current flow through the switching device that occurred during the first pulse duration time after the first pulse duration time has ended to determine the continuing presence of the fault;
• the controller being further configured to provide a second pulse signal to the switching device to cause a pulse generator within the switching device to generate a second pulse having a second pulse duration time that is longer than the first pulse duration time if it is determined that no fault current was present during the first pulse duration time;
• and
• the controller being further configured to analyze network voltages and the current flow through the switching device that occurred during the second pulse duration time after the second pulse duration time has ended to determine the continuing presence of the fault.