Harmonics are periodic distortions of voltage, latest, or electric power sine waves. Harmonics in power distribution systems are frequently attributable to non-linear masses for instance switched method dc ability supplies and adjustable velocity motor drives. + Các Web site, ?ng d?ng l?y d? li?u x? s? tr?c ti?p t? Minh Ng?c: K?t qu? c?p nh?t tr�