Harmonics are periodic distortions of voltage, latest, or electric power sine waves. Harmonics in electrical power distribution systems tend to be attributable to non-linear masses for example switched manner dc electrical power materials and adjustable pace motor drives.16 ??i bóng hàng ??u t?i Vi?t Nam h?a h?n s? mang ??n nh?ng tr?n c?u h?p d?n