Ultrasensitive lightweight magnetic probe for non-destructive inspection of high-voltage overhead lines

For power utilities with comprehensive asset management programs, inspection of high-voltage line conductors is critical to ensure network reliability. Current non-destructive testing methods for ferromagnetic materials are still not completely adapted to perform these inspections quickly, safely and accurately. This paper presents the prototype of a novel probe that is specifically designed for the inspection of conductors steel core. It is based on a novel lightweight and symmetrical design intended for automated inspection by drone. The sensitivity of the new probe is achieved by compensating for the conductor's imperfect centering during inspection and by creating a zero magnetic field point that allows the use of low range and accurate fluxgate sensors. Experimental results verify that the prototype is capable of detecting broken wires, quantifying metal area loss and inspecting steel core splice joints under unsaturated magnetization, which is the key element to achieve a lightweight probe.