Sinusoidal frequency is one of the basic parameters.The high-accuracy sinusoidal frequency measurement technology has wide applications.But in the aspect of low-frequency sinusoidal frequency measurement

the current sinusoidal frequency measurement technology usually has the defects of low accuracy under the environment of harmonic noise interference.This paper proposes a novel sinusoidal frequency measurement method based on precise calculation of initial phase by means of sequence and deconvolution sequence.The measurement principles of precise initial phase sequence calculation and orthogonal mixing calculation for sequence phase measurement are analyzed.It is pointed out that the mixed-frequency interference is the main cause of the measurement error.By severely inhibiting the interference of mixed-frequency

and by calculating the full phase difference of sequence and deconvolution sequence

accuracy of sinusoidal frequency measurement is improved under the environment of harmonic noise interference.Mathematical calculation

simulation test and the physical experiment results also verify the correctness and reliability of the proposed method.