Effect of Nonideal Linear Polarizers, Stray Magnetic Field, and Vibration on the Accuracy of Open-Core Optical Current Transducers

Because of the lower cost of open-core optical current transducers (OCTs), they are the first choice among different types of OCTs if their accuracy fulfills the requirements. Therefore, this paper studies the accuracy of the open-core OCTs and attempts to increase the accuracy using special considerations. First, errors due to nonideality in linear polarizers have been determined using Jones matrices mathematics. Then, the effects of vibration and stray-field on the accuracy of the open-core OCTs have been investigated. For this purpose, the OCT has been modeled macroscopically applying finite element method in COMSOL Multiphysics. The results are validated by means of comparison with experimental and computational results. At last, different topologies have been proposed to reach higher accuracies but retain the low price. Results show that the open-core OCT is very sensitive to external effects, but by special techniques the OCT can be accurate enough to work in high-voltage substations.