A.變壓器故障產(chǎn)生少量氣體 B.變壓器運行產(chǎn)生振動 C.發(fā)生穿越性短路 D.氣體繼電器或二次回路故障
A.5~8 B.10~15 C.15~20 D.25~30
A.0° B.45° C.90° D.180°