Improvement of FDR Methods for Identifying Defects of Jointed HV Cable

Abstract

This paper considers frequency domain reflectometry (FDR) as an effective way to locate high voltage (HV) cable defects. The formula relating FDR to cable local equivalents impedance value is presented, and critical methods such as window function, frequency step, and bandwidth to process FDR data before Inverse fast fourier transform (IFFT) are also demonstrated. Finally, a multi-periods reflection analysis from the IFFT curve is introduced with illustrations from fields measurement to improve the identification of defects for cables with multiple joints.