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 ch?nh)Harmonics are periodic distortions of voltage, present-day, or electricity sine waves. Harmonics in electric power distribution systems in many cases are because of non-linear masses for example switched manner dc power supplies and adjustable pace motor drives. + B?n