Harmonics are periodic distortions of voltage, current, or electricity sine waves. Harmonics in electrical power distribution techniques are often because of non-linear hundreds such as switched manner dc power supplies and adjustable velocity motor drives. + Các Internet 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 t