Optical fibre current sensor for electrical power engineering

The paper presents the experimental results of the investigations of optical fibre current sensors with an external transformation. The head of the sensor is made of the glass which has a high value of the Verdet constant. The sensor was built on the glass bar (with high value of the Verdet coefficient), polarisers, plastic optical fibres, a light source and a detector module. The paper deals with magnetic field measurements of two types of electrical current conductors: a typical conductor with circular cross-section and a busduct. Output signals from the optical current sensor were displayed on the digital oscilloscope and memorized in μComp for a further analysis. This type of sensor was investigated on a laboratory stand and on an electrical power line which included conductor where the high intensity electric current flow. The constructed optoelectronic current sensor was tested for detection of current with intensity of the order of 200 A, with an accuracy of a few percent. Practically, the upper border of the current detection by means of this sensor is much higher.