The Possibility of Fault Location in Cross-Bonded Cables by Broadband Impedance Spectroscopy

Broadband impedance spectroscopy (BIS) provides a new method for cable fault location, however, this method has not been properly used in locating cable fault of cross-bonded (CB) cables due to the geometric discontinuity of impedance spectroscopy measurement loop. This study addresses the possibility of fault location by BIS in CB cables. First, this paper proposes a fault location method by transforming BIS in frequency domain into the location function in space domain with the aid of integral transformation (IT). The kernel function ej2βxis used to obtain fault location function. Second, this paper demonstrates an impedance spectroscopy measurement loop in CB cables. BIS in CB cables is observed having a generalized orthogonality with the kernel function ej2βx. Given this, the IT method is applicable for fault location of CB cables. Finally, this study carries out the location experiment of cable joints on a 110 kV CB cable in cable trench. The experiment shows that BIS in CB cables could be obtained by the loop proposed in this paper. Besides, the results verify the possibility of fault location in CB cables by IT method using BIS.