s?a mã ngu?n]Harmonics are periodic distortions of voltage, existing, or electric power sine waves. Harmonics in power distribution units in many cases are due to non-linear masses for instance switched method dc energy provides and adjustable velocity motor drives.TRang ch? L?ch thi ??u Tr?c ti?p Nh?n ??nh B?ng x?p h?ng Video M?ng xã h?iThe toug