On-line Cable Mapping System

How it Works

When significant levels of partial discharge (PD) activity are detected on MV/HV/EHV cable circuits, it is imperative that the site(s) of the PD along the length of the cable are located to direct preventative maintenance intervention in the form of a cable repair. To locate the site(s) of PD activity along cable circuits, HVPD apply the technique of On‑line Cable Mapping using the technique of time-domain reflectometry (TDR).
 
This is achieved using the PDMap© v8 software>expansion software module and HVPD Portable Transponder System to carry out diagnostic TDR OLPD measurements along the cable length.
 
The On-line Cable Mapping technique is non‑intrusive, as it uses split-core, inductive high frequency current transformer (HFCT) sensors connected to the earth points of the cable at the cable termination. A PD site can be accurately located to within 0.5–1% of the length of the cable on long lengths of cable.
 

Example of PD Site Location

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