Current Measurement with Optical Current Transformer

The development of power electrical systems causes attention to accuracy of protection elements and measurement values. So we need some new measuring devices with high accuracy for power transmission lines. One of these devices is Optical Current Transformer (OCT). Optical current transformers are suitable for power system protection and can replace the magnetic current transformers. In this paper, we described a comparison between optical current transformers and conventional current transformers. Using an optical current transformer has several advantages, e.g. high accuracy, low weight, easy installation and no-saturation. But it has some disadvantages also, like if the magnetic fields induced by the currents through other conductors is sufficiently high, the fault current measured will have some errors. In general, the optical current transformer device is more reliable and suitable for new power systems.