Harmonics are periodic distortions of voltage, existing, or energy sine waves. Harmonics in ability distribution systems are frequently brought on by non-linear hundreds for instance switched mode dc electricity materials and adjustable speed motor drives.Không ?? v?n n?n "?n ch?n" ?e d?a th? thao Vi?t Nam Ch? trong vòng ch?a ??y n?a n?m, th? tha