Abstract:Aiming at the approximate measurement of magnetic rotation angle in optical current sensor based on light intensity de-tection mode, this paper proposes a current measurement method based on triangular constant transformation to recon-struct magnetic rotation angle, so as to avoid the large current measurement error caused by the approximate measurement of the magnetic rotation angle. By extracting the DC component and the AC component of the light intensity signal de-tected by the photoelectric detector, the sine signal containing the magnetic rotation angle is directly obtained by dividing the two components, and then the triangular identity transformation method is used to linearly demodulate the magnetic rotation angle and reconstruct the current waveform. The experimental results show that the relative error of current measurement does not exceed 1.40% in the current range of 0.05A ~ 0.50A, which is less than the approximate linear measurement method, and the magnetic rotation angle and the current have a good linear relationship.