Abstract:In order to solve the problem of spectrum aliasing caused by high harmonics, the low-pass filter (LFP) is used by the bay control unit (BCU) before sampling in general. In view of the attenuation of 2~15 times harmonics caused by the low pass filter, and the limitation of fixed compensation method, a frequency autocorrelation compensation algorithm is designed in this paper, in order to ensure the measurement precision, the real-time compensation coefficient of the amplitude and phase is calculated according to the practical frequency calculation, at the same time, in view of the high harmonics influence on frequency calculation, a rotation vector frequency measurement method is designed in this paper, increases the precision of frequency calculation effectively., the effectiveness of the improved scheme is proved through test and actual application.