Study On The Property Of The Optical Current Sensor Based On Faraday Magneto-optical Effect

With the voltage level and capacity development of the power system and the development of digital substation, the traditional power current sensor is increasingly difficult to adapt to system requirements. Optical current sensor with small size, low cost, safe and reliable operation to meet the requirements of digital substations etc., become the object of research focus. Optical current sensors have different principle, advantages and disadvantages also. Still, magneto-optical medium is found in the greatest bottleneck constraining the development of optical current sensors which have different principle. In addition, there are few research of response characteristics. Therefore, this paper uses two new magneto-optical media, MR3-2 new magneto-optical glass and ferrofluid, do system research of response characteristics of the optical current sensor based on Faraday magneto-optical effect.At first, the basic principles of Faraday magneto-optical effect and the related theories have been introduced, focuses on the classical theory of Faraday magneto-optical effect and quantum theory of Faraday magneto-optical effect of Paramagnetic material.Secondly, the response characteristics of the optical current sensor based on Faraday magneto-optical effect have been simulated according to the Malus Law. Include: Waveform of response, Amplitude characteristic, Frequency characteristic in AC sine wave excitation; Waveform of response, Amplitude characteristic in square excitation. The simulation can provide appropriate parameters and conditions, and basis is provided for determining the parameters of experiment.Then, the experiment platform of the optical current sensor based on Faraday magneto-optical effect in this paper has been introduced and established. Parameters of important devices in this experimental platform have been calculated and introduced. To further improve the experimental platform provides an effective basis.Finally, based on the experimental platform, with the MR3-2 magneto-optical glass and ferrofluid, response characteristics of the optical current sensor based on Faraday magneto-optical effect were studied. Include: Waveform, Amplitude characteristic and Frequency characteristic of response in AC sine wave excitation; Waveform of response in square impulse excitation; Temperature characteristics of response in AC sine wave excitation. Through the analysis of experimental data, found the reason of "frequency multiplication" phenomenon in ferrofluid.Made a number of improvements of experimental platforms and the magneto-optical medium parameters, and the different feature of two kinds magneto-optical medium were analyzed.