短語詞組短語current of commutation 換曏電流zero electric current commutation 零電流換曏the current commutation principle 電流轉(zhuǎn)移原理zero -current commutation 零電流換流current commutation principle 電流轉(zhuǎn)移原理current commutation in line 電流換流four step current commutation 四步換流zero current commutation 零電流換流forced current commutation 強(qiáng)迫換流 返回 current commutation