IEC_60909 Short Circuit Study

PTW IEC_60909 calculates short-circuit currents using the equivalent voltage source as required by the IEC 60909 standard. With PTW IEC_60909, three-phase and unbalanced fault duties for electrical power systems are calculated in compliance with the IEC 60909 standards for low, medium, and high voltage systems.


  • Design safer systems utilizing IEC-rated equipment by complying with IEC 60909 standard for short circuit current determination.
  • Improve accuracy by using load flow results or voltage factor table to assign system prefault voltages.
  • Eliminate duplicate entry by sharing the same project database and one-line diagrams with other PTW study modules.
  • Communicate effectively with one-line datablocks and tabular reports.


  • Three phase, single-line to earth, double-line to earth, and line to line faults.
  • Earth return current for double line to earth faults.
  • Options to use load flow results or voltage factor table for assigning system prefault voltages.
  • Models transformer and generator earthing impedances.
  • Models transformer taps in all three sequence networks.
  • Complete representation of the positive, negative, and zero sequence networks.
  • Calculates near/far and meshed/non-meshed status for each source.
  • Reports positive, negative, and zero sequence Thevenin impedance at each bus.
  • Reports total initial symmetrical apparent power S"k.
  • Reports total asymmetrical breaking current, Ib at user defined Tminimum.
  • Reports total steady state apparent power Sk.
  • Reports total initial symmetrical current I"k.
  • Reports total aperiodic component of short circuit current, idc at Tminimum.
  • Reports total peak current, ip.
  • Reports symmetrical breaking current, Ib at user defined Tminimum.
  • Reports steady state symmetrical current, Ik.
  • Reports system branch flows to each fault location.