November 9, 2020 | Improved early fault detection in electrical cables

CEA-List, a CEA Tech institute, partnered with Nicomatic to develop a non-destructive testing (NDT) method for detecting the early signs of faults in electrical cables. They used a new, more sensitive and effective type of reflectometry.

Electrical cables are everywhere in our environment, carrying both energy and data for a variety of uses. The early detection of faults in these cables is vital—and today’s commonly-used reflectometry-based systems[1] are plagued by a phenomenon known as self-blinding, which prevents faults from being detected early on. The Carnot CEA List recently came up with a solution to this problem in research conducted under the institute’s joint lab with Nicomatic.

In electrical cables—one-dimensional systems—the sensor is located in a direct line of sight with the electrical signal that is sent to complete the test. The test signal does not contain any information, but still crowds out the signal returned via the channel being tested—and it is this far-less-perceptible signal that contains the information that is useful for the test. Nicomatic turned to CEA List experts to solve this problem, which they did by generating a signal opposite to the excitation signal and adding this signal to the channel’s response. This ensures that the return signal only contains useful information.

The initial test results indicated that the new technique could effectively improve the detection of faults with very weak signatures. It could potentially be used in a wide range of applications, from self-diagnosing cable and cable network systems in the space (reusable space launchers), aeronautics, automotive (autonomous vehicles), rail, and energy transmission and distribution industries.

[1] Reflectometry is a technique where an electrical signal is propagated inside the system being tested. When the signal encounters a fault inside the system, part of the signal’s energy is sent back to the point from which it originated. This reflected signal is analyzed for information on the system being tested.


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