Harmonics are periodic distortions of voltage, recent, or power sine waves. Harmonics in power distribution units in many cases are brought on by non-linear masses such as switched method dc electrical power materials and adjustable speed motor drives.B??c 1. Ng??i ch?i v?n l?a ch?n link ?? truy c?p an toàn t?o ?i?u ki?n các b??c sau th?c Hello?n