Method and apparatus for pin-pointing faults in electric power lines

A method of locating a fault along a power transmission line comprising:

• isolating the transmission line from a power distribution system of which the line is usually a part;
• providing a single electromagnetic sensor adjacent a point on said transmission line, said sensor being electrically isolated from said transmission line;
• applying a high voltage signal to the transmission line to induce an arc at said fault, said arc producing a fault current;
• determining whether said arc is located to a first side of said point, or to a second side of said point opposite said first side, said determining comprising:
• receiving with said single electromagnetic sensor an electromagnetic field produced by an initial surge of said fault current, said electromagnetic field causing the sensor to produce an electrical signal corresponding thereto;
• if said electrical signal has a first polarity, identifying the fault as being positioned to the first side of said point;
• if said electrical signal has a second polarity opposite the first, identifying the fault as being positioned to the second side of said point.

A method for locating an arcing fault on an AC power distribution line from a location remote of the line, the method comprising:

• sensing, from a location remote of the line, current pulses passing through a region of the line;
• distinguishing an initial current pulse directly associated with a fault current from other current pulses;
• detecting a polarity of said initial fault current pulse;
• and
• determining, from the detected polarity of the initial fault current pulse, a direction to the fault;
• wherein the arcing fault is located by a sensor not physically coupled to the line.

In a method of operating a power distribution system, the system including a line for carrying an AC power signal, the system including a device coupled to the line at a point therealong for sensing data relating to the voltage thereat and relating to electromagnetic fields thereat, the device utilizing said sensed data to determine the direction to a cause of an anomaly in said system, an improvement wherein the anomaly is a fault which causes a high amplitude fault current to flow through said line, and in which the method further includes:

• positioning a plurality of said devices at a plurality of different points along said line;
• generating, at each of said devices, signals corresponding to said sensed electromagnetic fields, and discriminating from said signals a signal produced by an initial surge of the high amplitude fault current;
• generating, at each of said devices, data indicating the direction to the fault therefrom;
• and
• collecting said data from said plurality of devices to locate the fault;
• wherein said logged data memorializes not just the passage of a fault current through said plurality of points, but the direction to the fault, allowing a fault to be located rapidly and without repeated reclosure of system breakers.