Harmonics are periodic distortions of voltage, existing, or energy sine waves. Harmonics in electric power distribution devices in many cases are brought on by non-linear masses for example switched method dc power materials and adjustable velocity motor drives.Bên c?nh ?ó, m?t s? gi?i ??u có s? tham gia c?a ??i tuy?n Vi?t Nam c?ng nh?n ???c nhi