Set Of Magnetic Fiber-optic Current Sensors

A new kind of Ferromagnetic collector type fiber-optic current sensor (FCFOCS) is presented in this paper. Its background, principle, construction design, experimental evaluation and error analyzing is also discussed.As the development of the electrical system, the conventional magnetic current transformer can not implement the detection for the large current in high voltage, so finding a substitute is essential. FCSOCS takes fiber as its transmission material, takes magneto-optic material which work followed the Faraday magneto-optic effect as its sense component and uses ferrite material accumulating the magnetic field around the current lead. The sensor has many good characters such as low cost, stable construction, high sensibility and easy to detect the current, thus it is very applicable for the current detection in high voltage of the electrical system.In this paper, the actuality of fiber-optic current sensor is introduced, the sorts of the current sensor are presented, and the merits and the demerits of these kinds of sensors are compared. A new kind of FCFOCS construction that combines the magneto-optic material with the ferromagnetic ring concentrator based upon the usage and the background is also brought in this paper. This FCFOCS construction has many characters of BGOCS, such as large dynamic range, good stability, and high precision, little affected by linear bi-refraction. In addition, the ferromagnetic ring concentrator increases the system precision, reduce the system cost.The construction of FCFOCS is presented in two aspects: optic-circuit design and electro-circuit design. In optic-circuit design, the optic source, the collimator and the polarimeter is chosen; the paramagnet magneto-optic glass is used as its main component, which Verdet constant is-0.33min/Oe ? cm. In electro-circuit, laser driving circuit makes its stable output of optic source by light power feedback. Optic detecting and amplifying circuit makes the optoelectronic signals exchange, amplify, filter and get the voltage signals.Finally, the experimental equipment, experimental evaluation and error analyzing is presented. It can be proved by the experimental evaluation that FCFOCS can detect the current peak value and output the wave precisely.