The operating principles of three kinds of magneto-optical current transducers（MOCTs） based on single optical path detection method

dual optical paths detection method

and improved dual optical paths detection method

respectively

are analyzed.It is found that the output signals of the MOCTs are influenced by both the fluctuation of operating wavelength and the intersecting angle error of optical axes of polarizer and analyzer.Variation scope and variation trend of the operating wavelength and the intersecting angle error under different central operating wavelengths are analyzed when the output signals of the MOCTs can satisfy the accuracy requirement of 0.2 class or 0.5 class

and the performances of three kinds of MOCTs are compared.This study may offer a reference for the MOCT designers.