Harmonics are periodic distortions of voltage, existing, or ability sine waves. Harmonics in ability distribution devices tend to be a result of non-linear masses for example switched method dc energy supplies and adjustable velocity motor drives.HLV 'b?t ??c d?' c?a ?H V?n Lang giúp ng?a ô th?ng ??i di?n m?nh Ánh Viên ch?y xe h?n thirty km t?i