Research On Temperature Compensation Of Magneto-optic Fiber Current Sensors

Fiber current sensors have many superiorities,such as anti-electromagnetic interference,wide dynamic range,great insulation performance,fast fault response,compact size,and light weight,etc.These merits make them valuable in generator fault detection and protection,high-voltage transmission network fault detection,and wind or solar power generation network measurement and monitoring.However,the main impediment to the practical implementation of fiber current sensors based on the magneto-optical crystal is temperature dependency.In the article,the temperature compensation method of magneto-optical fiber current sensors is investigated to improve the sensor’s accuracy,which is of great significance to realize its wide application.The temperature compensation method of the magneto-optical fiber current sensors is studied in this article.The main contents are as follows:1.A temperature compensation method based on static bias is proposed.By adding a bias magnetic field to the sensor with two toroidal permanent magnets.The temperature compensation of sensors can be implemented only by measuring the Faraday rotation angles induced by the total magnetic field and the bias magnetic field theoretically and experimentally.2.An experimental system is designed and established,and the temperature compensation method is experimentally studied.The experimental results show that the maximum relative error of the sensor is reduced from ±8.0% to ±2.0% in the temperature range of-20℃ to 60℃ after the application of the proposed method.After the correction of the nonlinear response of the Faraday crystal,the relative error is further reduced to ±1.0%.3.The intelligent algorithm of temperature compensation is studied.By applying BP neural network algorithm and optimizing parameters,the relative error of the sensor is reduced to ±0.5% in the temperature range of-20℃ to 60℃.