A.0.1s B.0.3s C.0.5s D.0.7s
A.動(dòng)力系統(tǒng) B.電力網(wǎng) C.電力系統(tǒng) D.配電網(wǎng)
A.繼電器數(shù)量減少 B.接線簡(jiǎn)單 C.投資少 D.動(dòng)作時(shí)間精確