The paper presents the measurement system of a fiber optic polarimetric current sensor using the Faraday effect. The system is powered by 1550 nm light, and the magneto-sensitive element is a fiber optic coil made of single-mode fiber. The analysis of the influence of disturbances on the sensor's operation in the basic configuration was made. The change in the parameters of the light wave depending on the induced damaging birefringence of the linear and circular birefringence resulting from the Faraday effect is presented. The results of measurements of sinusoidal alternating currents with mains frequency in the amplitude range from 100 A to 1000 A are presented. Metrological analysis of the sensor was made. The sensitivity of the measurement system was determined and the uncertainty of the current measurement was estimated using a fiber optic polarimetric sensor, the value of which does not exceed 2%.
In the paper the polarimetric current sensing solution used for measurements of high amplitude currents and short durations is presented. This type of sensor does not introduce additional resistance and inductance into the circuit, which is a desirable phenomenon in this type of measurement. The magneto element is a fiber optic coil made of spun fiber optic. The fiber in which the core is twisted around its axis is characterized by a small effect of interfering magnitudes, ie mechanical vibrations and pressure changes on the polarimeter. The presented polarimetric current sensor is completely fiber optic.
Experimental results of a proposed sensor construction solution operating at 1550 nm and methods of elimination of influence values on the fiber optic current sensor were presented.
The sensor was used to measure the impulse current. The generated current pulses are characterized by a duration of 23μs and amplitudes ranging from 1 to 3.5 kA. The currents in the discharge circuit are shown. The measurement uncertainty of the amplitude of the electric current in the range of measured impulses was determined and estimated to be no more than 2%.