FormulasΒΆ
\[\begin{split}\sf \left[ {\begin{array}{cc}
\sf Y_{VV} & \sf Y_{VI} \\
\sf Y_{IV} & \sf Y_{II} \\
\end{array} } \right]
\left[ {\begin{array}{c}
\sf \underline V_k \\
\sf \underline V_u \\
\end{array} } \right]
=
\left[ {\begin{array}{c}
\sf \underline I_u \\
\sf \underline I_k \\
\end{array} } \right]\end{split}\]
\[\sf \underline V_u = Y_{II}^{-1} \left( \underline I_k - Y_{IV} \underline V_k \right)\]
\[\sf \underline I_u =Y_{VV} V_k + Y_{VI} \underline V_u\]
\[\begin{split}\sf \underline V_p = V_u[m] \\
\sf \underline I_p^{pq} = \frac{\vec S_p}{\vec V_p} \\
\sf i\; in\; a,b,c\end{split}\]