trong m?t kho?n th?i gian nh?t ??nh tr??c khi ?i?u ch?nh, t?t nh?t b?n nên dùng ph??ng pháp t? ??ng ho?c xây d?ng hàm ?? ki?m tra v?i d? li?u.Harmonics are periodic distortions of voltage, present, or power sine waves. Harmonics in electricity distribution methods in many cases are caused by non-linear hundreds including switched method dc a