Harmonics are periodic distortions of voltage, present, or electrical power sine waves. Harmonics in electric power distribution methods are frequently caused by non-linear hundreds for example switched manner dc electrical power supplies and adjustable velocity motor drives.Gi?i m?i (bao g?m t?t c? gi?i nào có s? thay ??i, c?p nh?t m?i ho?c ?i?u