Design Of A Fiber-Optic Interferometer Current Sensor

As important equipments in electric power industry, current transducers play a primary rolefor working well and calculating precisely in power supplying system. With the development ofnational economy, new high voltage level emerges continuously, and high accuracy ofmeasurement and protection are demanded increasingly. It is an absolute trend that novel opticalcurrent transducers substitute the old electromagnetic current transformer. Based on modernelectronics technology and optics technology, fiber-optic interferometer current sensors havealready been accepted by electric power engineering because of attractive characteristics of highaccuracy, high reliability and wide bandwidth. In order to satisfy the demands for electric current transducer in modern electric powerindustry, this issue describes a novel fiber-optic interferometer current sensor, which combinespolarized-light interference technology with fiber sensing technology. Compared with the hybridfiber-optic current transducers, novel current sensors don't need special power supply forhigh-voltage unit. The advantages of the sensor are simple structure, wide dynamic range andbandwidth, especially insensitive to temperature and vibration. This issue designs band pass filter and low pass filter. The digital demodulation is realized byuse of recent digital signal processing technology. Much research has been made on the devicesselection, signal processing and software design. The whole circuit's timing generation andsynchronization are realized with the complex programmable logic device. At last, the analysis about this interferometer current sensor is described. The current sensorwe designed is much better than traditional current transducer.