Earth Potential Rise (EPR) Computation for a Fault on Transmission Mains Pole

The prologue of new High Voltage (HV) transmission mains into the community necessitates earthing design to ensure safety compliance of the system. Conductive structures such as steel or concrete poles are widely used in HV transmission mains. The earth potential rise (EPR) generated by a fault on these structures could result to an unsafe condition. This paper discusses information on the input impedance of the over head earth wire (OHEW) system for finite and infinite transmission mains. The definition of finite and infinite system is discussed, maximum EPR due to pole fault. The simplified equations for EPR assessments are introduced and discussed for the finite and infinite conditions. A case study is also shown.

Authors:

• M. Nassereddine
• J. Rizk
• A. Hellany
• M. Nagrial

Keywords:

• Coupling Factor
• Earth Grid
• EPR
• Fault Current Distribution
• High Voltage
• Line Impedance
• OHEW
• Split Factor
• Transmission Mains.

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