相与线电压电流#
$$
\left\{\begin{array}{l}
线电压：线与线之间的电压\\
线电流：某输电线的电流
\end{array}\right.
$$
$$
\left\{\begin{array}{l}
相电压：电源或负载电压\\
相电流：电源或负载电流
\end{array}\right.
$$星型连接#
$$
电流：相电流=线电流\\
电压：\left\{\begin{array}{l}
\dot{U}_{AB}=\sqrt{3}\angle{30\degree}\dot{U}_{AN}\\
\dot{U}_{BC}=\sqrt{3}\angle{30\degree}\dot{U}_{BN}\\
\dot{U}_{CA}=\sqrt{3}\angle{30\degree}\dot{U}_{CN}
\end{array}\right.电源侧与负载侧同理
$$三角型连接#
$$
电压：相电压=线电压\\
电流：\left\{\begin{array}{l}
\dot{I}_{AB}=\frac{1}{\sqrt{3}}\angle{30\degree}\dot{I}_{A}\\
\dot{I}_{BC}=\frac{1}{\sqrt{3}}\angle{30\degree}\dot{I}_{B}\\
\dot{I}_{CA}=\frac{1}{\sqrt{3}}\angle{30\degree}\dot{I}_{C}
\end{array}\right.电源侧与负载侧同理
$$三相对称电路的计算#
$$
将\Delta变换为Y型计算\\
由相线关系推算目标值
$$
