This standard provides guidance for the calculation of power station GPR and LI voltages and guidance for their appropriate reduction from worst-case values for use in metallic telecommunication protection design. Information is also included for the determination of the following:a) The fault current and the earth return current levels; their probability, waveform, and duration; and the impedance to remote earthing points used in these GPR and LI calculations as well as theeffective X/R ratio.b) The zone of influence (ZOI) of the power station GPR.c) The calculation of the inducing currents, the mutual impedance between power and metallictelecommunication facilities, and shield factors.d) The channel time requirements for metallic telecommunication facilities where non-interruptible channels are required for protective relaying.
Abstract
Revision Standard - Active.Guidance for the calculation of power station ground potential rise (GPR) and longitudinal induction (LI) voltages is provided, as well as guidance for their appropriate reduction from worst-case values, for use in metallic telecommunication protection design.
