Thermal Short-Circuit Current¶
Current Calculation¶
The equivalent thermal current is calculated as:
\[\begin{split}\begin{bmatrix}
\underline{I}_{th, 1} \\
\vdots \\
\underline{I}_{th, n} \\
\end{bmatrix} =
\begin{bmatrix}
\sqrt{m_1 + n_1} \\
\vdots \\
\sqrt{m_n + n_n} \\
\end{bmatrix}
\begin{bmatrix}
\underline{I}''_{k, 1} \\
\vdots \\
\underline{I}''_{k, n} \\
\end{bmatrix}\end{split}\]
where m and n represent the dc and ac part of the thermal load.
Correction Factors m and n¶
For short-circuit currents far from synchronous generators, the factors are given as:
\[n = 1
m = \frac{1}{2 \cdot f \cdot T_k \cdot ln(\kappa - 1)} [e^{4 \cdot f \cdot T_k \cdot ln(\kappa - 1)} - 1]\]
where \(\kappa\) is the peak factor defined here and \(T_k\) is the duration of the short-circuit current that can be defined as a parameter when running the short-circuit calculation.