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In the Loop

WG B2.56 – Ground Potential Rise at Overhead AC Transmission Line Structures During Power Frequency Faults


As transmission lines are often located close to areas of public access, public and worker safety is always top priority in the operation of transmission overhead lines and effective grounding of each line structure is necessary to provide safety, proper protection operation and acceptable lightning performance. Working Group B2.56 has examined the issues related to ground potential rise (GPR) on overhead transmission lines during power frequency faults and has recently produced Technical Brochure 694 to:

  • Raise awareness of potential safety risks associated with Ground (Earth) Potential Rise (GPR) for overhead lines;
  • Promote a safe operating environment near line structures during power frequency faults and;
  • Aid understanding of the strategic design approach associated with line grounding problems and available solutions for power frequency line faults.

The Australian members on the working group were Charles Crew and Tim De Grauw and Australian Panel Convenor John McCormack.

The Summary of the TB can be viewed HERE

The full Technical Brochure (TB) can be viewed on e-CIGRE and is free to members.  The cost to non members is €160.