Peak and RMS symmetrical short-circuit currents on a shipboard bus - IEC 61363-1 approach for switchgear sizing.
Formula
$$ I’’k = \frac{I\text{base}}{X’’_d}, \quad i_p = \kappa \cdot \sqrt{2} \cdot I’’_k $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $I_\text{base}$ | Base current = MVA/(√3·V) | A | derived |
| $X’’_d$ | Sub-transient reactance pu | pu | generator data sheet |
| $κ$ | Peak factor | - | IEC 61363 |
| $I’’_k$ | RMS symmetrical SC | A | result |
| $i_p$ | Peak SC | A | result |
Sources
- IEC 61363-1 - Short-circuit calculation for shipboard installations.