Harmonics are periodic distortions of voltage, recent, or ability sine waves. Harmonics in power distribution units will often be caused by non-linear masses which include switched mode dc electrical power provides and adjustable velocity motor drives. + Các Web page, ?ng d?ng quét t? ??ng d? li?u x? s? tr?c ti?p t? X? S? Minh Ng?c: K?t qu? c?