Underground jacketed and unjacketed power distribution and transmission cables are subject to ongoing deterioration. Furthermore, the concentric neutral (CN) wires in these cables can corrode and break. Power utilities have great interests in determining the condition of CNs -- in situ while they are energized in their normal state. The use of non-magnetic flexible chains to support current sensors enables a single sensing tool to inspect CN currents in underground power cables with various diameters. This approach lowers inspection costs by reducing tool inventories and technician time.
To refine this cable inspection approach, researchers at UC Berkeley have developed an inexpensive and safe means of tracking the motion of a CN current sensor during the inspection of high-voltage energized power cables. The Berkeley approach uses off-the-shelf wireless optical mouse systems along with specially developed software to simply, quickly, and safely obtain coordinates of the current sensor movement as the sensing device moves along or circumferentially around the cable under inspection.
The software enables the operator to keep the position display automatically within the allowable display area of a computer screen, or to adjust the display parameters for optimal monitoring of the sensor.