# 開路測試

## 計算

${\displaystyle \mathbf {W} =\mathbf {V_{1}} \mathbf {I_{0}} \cos \phi _{0}}$

${\displaystyle \cos \phi _{0}={\frac {\mathbf {W} }{\mathbf {V_{1}} \mathbf {I_{0}} }}}$

${\displaystyle \mathbf {I_{m}} =\mathbf {I_{0}} \sin \phi _{0}}$
${\displaystyle \mathbf {I_{w}} =\mathbf {I_{0}} \cos \phi _{0}}$

### 阻抗

${\displaystyle \mathbf {X_{0}} ={\frac {\mathbf {V_{1}} }{\mathbf {I_{m}} }}}$

${\displaystyle \mathbf {R_{0}} ={\frac {\mathbf {V_{1}} }{\mathbf {I_{w}} }}}$

${\displaystyle \mathbf {Z_{0}} ={\sqrt {\mathbf {R_{0}} ^{2}+\mathbf {X_{0}} ^{2}}}}$

or

${\displaystyle \mathbf {Z_{0}} =\mathbf {R_{0}} +\mathbf {j} \mathbf {X_{0}} }$

(以上為錯誤部份)

### 导纳

${\displaystyle \mathbf {Y_{0}} ={\frac {1}{\mathbf {Z_{0}} }}}$

${\displaystyle \mathbf {G_{0}} ={\frac {\mathbf {W} }{\mathbf {V_{1}} ^{2}}}}$

${\displaystyle \mathbf {B_{0}} ={\sqrt {\mathbf {Y_{0}} ^{2}-\mathbf {G_{0}} ^{2}}}}$

${\displaystyle \mathbf {Y_{0}} =\mathbf {G_{0}} +\mathbf {j} \mathbf {B_{0}} }$

${\displaystyle \mathbf {W} }$為瓦特計讀值

${\displaystyle \mathbf {V_{1}} }$為一次側所給電壓

${\displaystyle \mathbf {I_{0}} }$為無載電流

${\displaystyle \mathbf {I_{m}} }$為無載電流的激磁成份

${\displaystyle \mathbf {I_{w}} }$為無載電流的銅損成份

${\displaystyle \mathbf {Z_{0}} }$為激磁阻抗

${\displaystyle \mathbf {Y_{0}} }$為激磁导纳

## 參考資料

• Kosow. Electric Machinery and Transformers. Pearson Education India. 2007.
• Smarajit Ghosh. Fundamentals of Electrical and Electronics Engineering. PHI Learning Pvt. Ltd. 2004.
• Wildi, Wildi Theodore. Electrical Machines , Drives And Power Systems, 6th edtn.. Pearson. 2007.
• Grainger. Stevenson. Power System Analysis. McGraw-Hill. 1994.