Harmonics are periodic distortions of voltage, existing, or electricity sine waves. Harmonics in electrical power distribution units tend to be caused by non-linear hundreds which include switched method dc ability provides and adjustable speed motor drives.Á quân th? gi?i h?ng 50kg Nguy?n Th? Tâm và HC ??ng ASIAD 19 h?ng 75kg L?u Di?m Qu?nh ??