Analysis of HV bushing internal properties using DFR

DFR (Dielectric Frequency Response), also known as FDS (Frequency Domain Spectroscopy) is a measurement technique in which capacitance and losses (dissipation factor/tan delta or power factor) are measured over multiple frequencies to assess the insulation condition of test objects, such as power transformers, bushings, and current transformers (CTs). DFR technology is a long-established test procedure in laboratories that, in an innovative effort by Megger, was adapted for field use through the IDAX range of instruments.