93. 在正常的情況下,下列三相變壓器結線法中,那一種允許零序電流(zerosequence current)在一、二次側間流通?
(A)△-△ 結線 (delta-delta
connection)
(B)接地Y-接地Y 結線(grounded Wye-grounded Wye
connection)
(C)接地Y-不接地Y 結線(grounded Wye-ungrounded Wye
connection)
(D)不接地Y-不接地Y 結線(ungrounded Wye-ungrounded Wye
connection)。