# Peak Short-Circuit Current¶

## Current Calculation¶

The peak short-circuit current is calculated as:

where \(\kappa\) is the peak factor.

## Peak Factor \(\kappa\)¶

In radial networks, \(\kappa\) is given as:

where \(R/X\) is the R/X ratio of the equivalent short-circuit impedance \(Z_k\) at the fault location.

In meshed networks, the standard defines three possibilities for the calculation of \(\kappa\):

- Method A: Uniform Ratio R/X
- Method B: R/X ratio at short-circuit location
- Method C: Equivalent frequency

The user can chose between Methods B and C when running a short circuit calculation. Method C yields the most accurate results according to the standard and is therefore the default option. Method A is only suited for estimated manual calculations with low accuracy and therefore not implemented in pandapower.

**Method C: Equivalent frequency**

For method C, the same formula for \(\kappa\) is used as for radial grids. The R/X value that is inserter is however not the

**Method B: R/X Ratio at short-circuit location**

For method B, \(\kappa\) is given as:

while being limited with \(\kappa_{min} < \kappa < \kappa_{max}\) depending on the voltage level:

Voltage Level | \(\kappa_{min}\) | \(\kappa_{max}\) |
---|---|---|

< 1 kV | 1.0 | 1.8 |

> 1 kV | 2.0 |