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【多选题】
电力系统供电电压过低或过高产生的危害主要有（）。
A.
当电压过，白炽灯寿命将大为缩短，异步电动机、变压器铁芯损耗增加，电能波形变差
B.
当电压过低时，对照明负荷来说，白炽灯的发光效率和光通量都急剧下降，电灯发暗，荧光灯启动困难
C.
当电压过低时，对异步电动机电磁转矩显著减小，定子、转子电流增大，电动机过热；电热设备输出热能降低；移相电容器输出无功功率降低以及输电线路损耗增加等
D.
当电压过，家用电器使用效率将会提高
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